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WorkSpace
05-29-2008, 07:48 PM
Hello from down-under :wave: . This is my first post here, and I haven't made mead before. So I have been reading the newbee guide and some relevant threads. As an extract beer, wine and spirit wash brewer, I have been trying to make sense of the process. Two aspects of it seem odd to me, and maybe you could explain what I am missing.

I am trying to understand why it should be neccessary to heat the must. I understand that this is done to get rid of natural yeasts and micro-organisms. But I would have thought that honey is pretty clean stuff. We have jars of it that has been sitting on the shelves for years, and it is still fine. What happens if the must isn't heated. Has anyone done both and compared results?

The other thing I couldn't understand was aeration during the fermentation process. Is this really neccessary? With all the beer, wine and spirit washes I have made, I have never done this. After pitching the rehydrated yeast, the fermenter is closed up, the airlock is fitted and it is left alone for about a month (depending on temperature). I know aeration is done to promote yeast growth. But wouldn't it be better to ensure that adequate yeast is available before fermentation starts? I would have thought that interfering with the fermentation process would be counter-productive. Introducing air slows fermentation, and opening the fermenter increases the risk of contamination. What happens if you don't aerate?

I hope this doesn't sound too argumentative. I just need to understand why things have to be done. ???

akueck
05-29-2008, 08:23 PM
Welcome WorkSpace!

Good questions, and as you read more of the zillions of posts you're bound to find lots of opinions.

In a nut-shell, GotMead folks recommend NOT heating the must. As you said, honey is pretty darn clean. Moreover, heating will only destroy the delicate aromas of honey. Advice to heat is usually due to either historical recipes or recipes stemming from beer-brewing practices, both of which use heat during must/wort preparation.

Aeration is more important in mead than in other fermentations since honey is almost devoid of natural nutrients (which helps with the biologically clean part). Oxygen is needed to build up strong cell walls. As you said, a big healthy yeast pitch would reduce the oxygenation requirements. Not knowing exactly how you like to prepare your yeast, I can't comment on whether you'd need to do much additional aeration. The best thing you can do is a pair of batches, one with extra aeration and one without. No substitute for personal experience! (and be sure to post your results)

Again welcome and let us know what your first batch will be!

Medsen Fey
05-29-2008, 08:35 PM
Welcome to the forums WorkSpace!

Your are quite correct that honey is clean stuff - very little can survive in it, and those things that can are destroyed by the osmotic shift when you dilute the honey with water, so there is no need to heat honey musts. In fact, it may be detrimental as you boil off aromatic elements that you want to keep. You'll find most folks here don't heat other than a little warming to make the honey easier to pour.

As for the aeration, there have been good studies in wine that explain the need for aeration/oxygen. The oxygen stimulates the yeast to form more sterols that strengthen the cell membrane, allow for more efficient division, promote increased tolerance to alcohol, and allow nutrients to be taken in and utilized late in the fermentation. Completely anaerobic fermentation results in lower amounts of sugar utilization unless the must is supplemented with sterols and long chain fatty acids. Allowing air will actually speed the fermentation. For meads it seems to work the same. Pitching more yeast will not make them stronger or more alcohol tolerant. In wine, oxygenation on day 2 of fermentation seems to be the critical window, but typically folks here will aerate during the first 2 or 3 days - or up to the point that the gravity has dropped by 1/3 (the 1/3 sugar break).

I hope that helps, and if you continue using the search tool you will find much more discussion on these topics.

Good meading!
Medsen

Oskaar
05-29-2008, 08:42 PM
Hello from down-under :wave: . This is my first post here, and I haven't made mead before. So I have been reading the newbee guide and some relevant threads. As an extract beer, wine and spirit wash brewer, I have been trying to make sense of the process. Two aspects of it seem odd to me, and maybe you could explain what I am missing.

WELCOME TO GOT MEAD?!



I am trying to understand why it should be necessary to heat the must. I understand that this is done to get rid of natural yeasts and micro-organisms. But I would have thought that honey is pretty clean stuff. We have jars of it that has been sitting on the shelves for years, and it is still fine. What happens if the must isn't heated. Has anyone done both and compared results?

Heresy! Not heating the must???? Are you mad man???? LOL

J/K LOL - In fact you'll find most of us here don't heat their must in part because honey is indeed very clean (inherently very bacteriostatic due to the low amount of water) but more because when you heat honey you cook off the enzymes, proteins and delicate floral characters and other volatile aromas that translate more complexity and flavor into your mead.



The other thing I couldn't understand was aeration during the fermentation process. Is this really necessary? With all the beer, wine and spirit washes I have made, I have never done this. After pitching the rehydrated yeast, the fermenter is closed up, the airlock is fitted and it is left alone for about a month (depending on temperature). I know aeration is done to promote yeast growth. But wouldn't it be better to ensure that adequate yeast is available before fermentation starts? I would have thought that interfering with the fermentation process would be counter-productive.

Actually the reason that we aerate is to not only promote yeast growth, but because as generations of new yeast are produced during fermentation, those new generations need a constant supply of oxygen in order to form strong cell walls with other components (sterols, etc.) and keep the cell wall supple and flexible. If the cells do not get adequate supplies of oxygen and nutrient the cell walls will become brittle and they will not form enough strength to regulate osmotic pressure and will undergo premature autolysis. During that time before they do die off they will be stressed from lack of oxygen and nutrient and produce off flavors. When you see a mead fermentation that lasts more than a couple of weeks what you're seeing in many cases is an under aerated and nutrient deprived fermentation.

From a recent SO2 in Wine lab report I did:
...snip...Molecular oxygen serves as a micronutrient for many organisms, required for the biosynthesis or degradation of many compounds. PPO successfully competes with the microbes present in wine for O2. Oxygen is required by the yeast for optimal ethanol tolerance (this is why we aerate in order to get O2 into the must for the yeast so they can synthesize sterols to strengthen the cell walls and have a higher ETOH tolerance), if PPO activity is unchecked, the yeast may be in a nutrient deficient situation (in this case O2 as a nutrient). This is an additional reason to add SO2 in grape musts. It is not clear at the molecular level exactly how SO2 is able to inhibit PPO activity....snip...

OK, we're dealing with honey vs grape must here and the rate of aeration and stages of aeration are going to be different. With grapes you're dealing specifically with a couple of anti-oxidants that will compete with with yeast for oxygen as the skins are in contact with the juice (most specifically PPO - Polyphenoloxidase) While you don't have that in honey must, you do have higher osmotic pressure so a couple of aerations daily during the first 1/3 of the ferment is beneficial (in order to build strong cell walls) and will not present risk of oxidation because the oxygen is being stripped from the yeast cells by the rapid production of CO2.

From Dr. Clayton Cone of Lallemand:
Yeast need a trace amount of oxygen in an anaerobic fermentation such as meadmaking, winemaking and brewing to produce lipids in the cell wall. With out O2 the cell cannot metabolize the squalene to the next step which is a lipid. The lipids make the cell wall elastic and fluid. This allows the mother cell to produce babies, buds, in the early part of the fermentation and keeps the cell wall fluid as the alcohol level increases. With out lipids the cell wall becomes leathery and prevents bud from being formed at the beginning of the fermentation and slows down the sugar from transporting into the cell and prevents the alcohol from transporting out of the cell near the end of the fermentation. The alcohol level builds up inside the cell and becomes toxic then deadly. Lallemand packs the maximum amount of lipids into the cell wall that is possible during the aerobic production of the yeast at the factory. When you inoculate this yeast into your must, the yeast can double about three time before it runs out of lipids and the growth will stop. There is about 5% lipids in the dry yeast.

In a very general view:
At each doubling it will split the lipids with out making more lipids (no O2). The first split leaves 2.5% for each daughter cell. The second split leaves 1.25% for each daughter cell. The next split leaves 0.63%. This is the low level that stops yeast multiplication. Unless you add O2 the reproduction will stop. When you produce 3-5% alcohol beverage this is no problem. It is when you produce higher alcohol beverage or inoculate at a lower rate, that you need to add O2 to produce more yeast and for alcohol tolerance near the end of fermentation. You definitely need added O2 when you reuse the yeast for the next inoculum.

Dr. Clayton Cone


References:
Texts:
Bisson, L., 2005. VEN 124 Wine Production for Distance Learners, Lesson 5: Juice and Must Treatments and Additions Topic 5.2: Juice Additions
Boulton, R., V. Singleton, L. Bisson, and R. Kunkee. 1996. Principles and Practice of Winemaking. Chapman and Hall. New York
Peynaud, Emile, 1984. Knowing and Making Wine, (English Translation) John Wiley and Sons, Inc. USA

Journal Articles:
Baldwin, G., Basic Effects of Sulfur Dioxide on Yeast Growth. American Journal of Enology & Viticulture Volume 2: 45–53. 1951
Cocolin, L., and D.A. Mills Wine Yeast Inhibition by Sulfur Dioxide: A Comparison of Culture-Dependent and Independent Methods. Am. J. Enol. Vit. 54: 125 – 130. 2003

Other Articles:
Delteil, D., Enological yeast effect on the sulfur dioxide content and management in wines. Institut Cooperatif du Vin, 1 – 4 1992




Introducing air slows fermentation, and opening the fermenter increases the risk of contamination. What happens if you don't aerate?

Introduction of air does not slow fermentation. Opening the fermenter does indeed increase the risk of contamination, but with proper aseptic technique that possibility is heavily mitigated. If you don't aerate you'll run into issues as outlined above.




I hope this doesn't sound too argumentative. I just need to understand why things have to be done. ???


Not at all, they're good questions. I hope my answers will help you decide to try something different and compare your results in a blind tasting with friends and other mead makers.

Cheers,

Oskaar

wayneb
05-30-2008, 12:06 AM
Well, I'm coming late to this party, but let me add my welcome to the chorus! You've stumbled on the most comprehensive compendium of mead information in the world here at GotMead, so it is understandable that if you have perused the forum postings as well as read the newbee's guide, you have seen some of the evolution of thought and the results of research performed specifically on fermentation kinetics in mead musts over the past several years. We've all revised our processes based upon the information that we've gleaned, and our own experiences that we've shared, in recent years. As you've probably seen, Oskaar is the best single source of detailed data to support all the techniques espoused here -- without him, we'd still be in the meadmaking Dark Ages. ;) But the evolution of process that occurs amongst the participants of this forum is truly a group effort, so we tend to have access to the best current thoughts of the meadmaking community as a whole.

Your question about heating has obviously been put to rest -- heating was an old technique that has fallen out of favor in recent years as we have learned that it is not necessary, and may be detrimental, to the results.

The issue of oxygenation of mead must is a newer concept, borne of both recent research into optimization of wine fermentation as well as our personal experiences, having done batches of mead both with and without various aeration techniques applied. The bottom line is that mead musts, for all the reasons cited by Oskaar and Medsen, benefit greatly from the addition of oxygen into the must between yeast pitch and approximately the 1/3 sugar break (the point at which 1/3 of the fermentable sugar has been consumed by the yeast). That might be counter-intuitive to anyone in the hobby for a number of years -- it certainly took me a while to come around to adopting the process -- but the results that I've achieved using early aeration of mead musts have been nothing short of phenomenal! First, primary fermentation times have been cut from weeks (or months) to just days for musts of all starting gravities. Second, and more importantly, my resulting meads taste better! Under those circumstances, I will never "pitch and forget" a mead must into a closed carboy again.

WorkSpace
05-30-2008, 01:03 AM
Thanks, guys, for your welcomes and helpful information. It all makes good sense. There certainly is a huge amount of info here. I have only skimmed some of it, but I have probably seen enough of it to get started - experience is the best teacher. So it is time to jump in the deep end. But I don't even know what mead tastes like, and I am wary of ending up with a 23 litres of undrinkable hooch. If it is undrinkable, I suppose could run it through the still and make spirit :confused1:. But I would like to experiment with a smaller quantity, perhaps 5 litres. As a type 1 diabetic, I also have to keep away from the sweet stuff. So it will have to be dry. I will go to the homebrew shop tomorrow to see if I can get what I need. Any suggestions welcome! ;)

Oskaar
05-30-2008, 01:16 AM
Well, before you buy anything why don't you post up your idea for a recipe and we'll help you fine tune it to something that will be a great first batch.

Cheers,

Oskaar

holycontagion
05-30-2008, 01:22 AM
Welcome to the forums and congrats on what will hopefully be a new obsession. I'm pretty new to mead making myself and I'd like to direct you toward a book by Ken Schramm.

http://www.amazon.com/Compleat-Meadmaker-Production-Award-winning-Variations/dp/0937381802/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1212124727&sr=8-1

Long link heh. I've seen a few posts by Mr. Schramm here on the forums and this isn't a shameless plug for his book or anything hehe. I highly recommend his book and some constant usage of the search tool here on gotmead.com. So far everything I know about mead making has come from one or both sources. Good luck and happy mead making sir :D

WorkSpace
05-31-2008, 02:58 AM
Thanks for the comments. I will try to get hold of that book by Ken Scramm. It looks very good. And thanks Oskaar for offering to help with a recipe for the first batch. But I decided to "just do it". I don't like thinking too much before trying something new :confused5:. So I went to the local homebrew shop and got what I need to turn a 12 litre pale I have into a fermenter. And I got the ingredients for a basic 4 litre batch. This is essentially a training exercise, so I am keeping it simple. I am using "Tiffany's Easy Mead Recipe" (Tiffany runs the homebrew shop).

After assembling and sterilising the fermenter, I poured the honey into it and added water to 4 litres. I also added some potassium bisulfite, presumably to inhibit bacteria growth. I stirred it well and took a hydrometer reading, which was about 1.075. Tomorrow I will add the other ingredients, being an acid mix, tannin, nutrient salts and vitamin B. After rehydrating it, I will pitch the yeast (Lalvin EC1118).

Oskaar
05-31-2008, 04:57 AM
STOP STOP STOP!

Whatever you do don't add any acid up front.

Acid will drive the pH of the must down and more than likely stress your yeast and in turn cause your fermentation to limp along slowly or stall altogether. This is an old, brewer's approach to meadmaking and is not recommended.

The internal pH of a yeast cell is near neutrality (pH 6.5- 7.0), while the pH of the medium is 3.0 to 4.0. This creates a large gradient of protons, and entry of hydrogen ions into the cell is energetically favorable. Therefore, movement of amino acids is coupled with that of protons. Amino acid transporters transfer both an amino acid molecule and a proton into the cell. The proton is then exported out of the cell via a proton pump. The pump extrudes protons in an energy dependent manner since excretion occurs against the proton gradient.(Bisson 2005)

Hydrolysis of ATP provides the energy for operation of the pump. Continued amino acid uptake requires efficient excretion of the protons that are being co-transported with the amino acid; so amino acid uptake is a very energy intensive process.

Since amino acid uptake is coupled to protons it's no mystery that the pH of the medium (must in this case) affects amino acid uptake. If the pH is too low, below 2.7, protons tend to enter the cell due to passive proton flux. The proton pump must then be directed towards removal of these protons. The cell has a limited capacity for the removal of protons, thus at very low pH the cell is not able to sustain amino acid uptake due to the lack of capacity of the proton pump.

There are several other factors that impact fermentation and H2S production that are associated with pH as well, most of them are NOT good for your mead.

Hope this helps and that you read this BEFORE making that acid addition. I'd also hold off on the tannin until the end.

Cheers,

Oskaar

Teufelhund
05-31-2008, 10:26 AM
And if THAT doesn't help...Stable versions of Newton & Apos's iteration for computing the principal matrix pth root A1/p of an n x n matrix A are provided. In the case in which X0 is the identity. A parallel fast direct solution method for linear systems with separable block tridiagonal matrices is considered. Such systems appear, for example, when discretizing the Poisson equation in a rectangular domain using the five-point finite difference ...

:cheers:

:notworthy:

WorkSpace
05-31-2008, 09:17 PM
... Hope this helps and that you read this BEFORE making that acid addition. ...
Thanks, Oskaar, for that tip. I read your post just in time ... :laughing7: . While the technical explanation kinda went over my head :icon_scratch: , I read around the subject and found several references to this effect. The last thing I want is slow fermentation, and/or one that doesn't go the full distance. So I will only add the acid after fermentation has completed.

I added the other ingredients and pitched the yeast a few hours ago. I have just checked on the air lock and pressure is building up in there. At what point should I aerate, and how often should this be done?

wayneb
06-01-2008, 01:07 AM
Since Oskaar's offline at the moment, I can answer your question about aeration. The yeast need oxygen from the must during their exponential growth phase, and partly into the stationary phase, in order to produce the sterols that keep yeast cell walls flexible and permeable. Without a source of O2, as yeast bud and divide to reproduce, the available lipids (sterols) in each cell goes down, as the total quantity is shared by the parent and all daughters. This leads to the cell walls becoming less flexible, and harder to exchange fuel for waste products. As a result, the yeast will work harder, and exhaust themselves sooner, than if the proper amount of sterols are available for each cell.

So, oxygen in the first 1/3 of fermentation (the period when the first 1/3 of fermentable sugars are consumed), which corresponds to that exponential growth phase, is a very good thing. You can oxygenate by injecting pure gaseous O2 into the must, or you alternatively may aerate with forced air through an airstone, or simply vigorously stir the must, splashing as much as practical, to mix as much room air with the must as possible. Do this immediately prior to yeast pitch, and then at least once daily thereafter until the 1/3 sugar break has been reached. I actually aerate via an aquarium pump and sanitized airstone for 30 minutes prior to pitching, and I do the vigorous stirring approach post-pitch with most of my meads, performing it twice daily, for about 5 minutes per shot.

After the 1/3 sugar break your yeast are pretty well along in the anaerobic stationary phase, and adding more O2 does little to help them, and can actually end up oxidizing the mead. So, O2 (or air) is good early on, but undesirable thereafter.

WorkSpace
06-01-2008, 03:05 AM
Thanks for that, Wayne. I stirred vigorously before pitching, and I will do it again tomorrow. This is the first time that I am using this pale as a fermenter, and I am not sure that I have a good seal. So I will have to see what happens tomorrow.

If I understand it correctly, fermentation is an anaerobic process. And in the presence of oxygen, ethanol is not produced. Does this mean that aerating the must will, stop fermentation until there is no more available oxygen? That being the case, how long does it take to get fermentation going again? :confused1:

Medsen Fey
06-01-2008, 11:00 AM
Hello Workspace,

I'm glad to hear your batch it off and running!


If I understand it correctly, fermentation is an anaerobic process.

While fermentation is anaerobic, the presence of oxygen does not stop fermentation. In wine or mead musts, the high sugar content inhibits the yeasts' ability to utilize oxygen for energy generation, so it keeps fermenting the sugar as its source of energy. Even though the fermentation won't be stopped by air exposure, as Wayneb pointed out, after the 1/3 sugar break (the point where the yeast have consumed 1/3 of the sugar in the must), exposure to air and oxygen won't be helpful and may cause oxidized aromas (acetaldehyde) and flavors in your mead.

When you vigorously stir (or Whack The Crap out of it) you will de-gas the must and it may take a few hours for the CO2 to build back up and start bubbling again.

I hope yours turns out well.
Medsen

Dan McFeeley
06-01-2008, 11:55 AM
Hello Workspace,

I'm glad to hear your batch it off and running!


If I understand it correctly, fermentation is an anaerobic process.

While fermentation is anaerobic, the presence of oxygen does not stop fermentation. In wine or mead musts, the high sugar content inhibits the yeasts' ability to utilize oxygen for energy generation, so it keeps fermenting the sugar as its source of energy. Even though the fermentation won't be stopped by air exposure, as Wayneb pointed out, after the 1/3 sugar break (the point where the yeast have consumed 1/3 of the sugar in the must), exposure to air and oxygen won't be helpful and may cause oxidized aromas (acetaldehyde) and flavors in your mead.


I think you're referring to the Crabtree effect? Here's a quick Wikipedia description:

http://en.wikipedia.org/wiki/Crabtree_effect

Named after the English biochemist Herbert Grace Crabtree, the Crabtree effect describes
the phenomenon whereby the yeast, Saccharomyces cerevisiae, produces ethanol (alcohol)
aerobically in the presence of high external glucose concentrations rather than producing biomass
via the tricarboxylic acid cycle, the usual process occurring aerobically in most yeasts eg.
Kluyveromyces spp [1]. Increasing concentrations of glucose accelerates glycolysis (the breakdown
of glucose) which results in the production of appreciable amounts of ATP through substrate level
phosphorylation. This reduces the need of Oxidative phosphorylation done by the TCA cycle via the
Electron Transport System and therefore decreases oxygen consumption. The phenomenon is
believed to have evolved as a competition mechanism (due to the antiseptic nature of ethanol)
around the time when the first fruits on Earth fell from the trees [2].

Welcome to the forums WorkSpace!

Oskaar
06-01-2008, 12:08 PM
Thanks for chiming in Dan!

Hey Workspace, here's from one of my earlier posts about fermentation during the anaerobic phase. This is from Dr Clayton Cone of Lallemand who is the reigning yeast guru in the wine industry.




From Dr. Clayton Cone of Lallemand:
Yeast need a trace amount of oxygen in an anaerobic fermentation such as meadmaking, winemaking and brewing to produce lipids in the cell wall. With out O2 the cell cannot metabolize the squalene to the next step which is a lipid. The lipids make the cell wall elastic and fluid. This allows the mother cell to produce babies, buds, in the early part of the fermentation and keeps the cell wall fluid as the alcohol level increases. With out lipids the cell wall becomes leathery and prevents bud from being formed at the beginning of the fermentation and slows down the sugar from transporting into the cell and prevents the alcohol from transporting out of the cell near the end of the fermentation. The alcohol level builds up inside the cell and becomes toxic then deadly. Lallemand packs the maximum amount of lipids into the cell wall that is possible during the aerobic production of the yeast at the factory. When you inoculate this yeast into your must, the yeast can double about three time before it runs out of lipids and the growth will stop. There is about 5% lipids in the dry yeast.

In a very general view:
At each doubling it will split the lipids with out making more lipids (no O2). The first split leaves 2.5% for each daughter cell. The second split leaves 1.25% for each daughter cell. The next split leaves 0.63%. This is the low level that stops yeast multiplication. Unless you add O2 the reproduction will stop. When you produce 3-5% alcohol beverage this is no problem. It is when you produce higher alcohol beverage or inoculate at a lower rate, that you need to add O2 to produce more yeast and for alcohol tolerance near the end of fermentation. You definitely need added O2 when you reuse the yeast for the next inoculum.

Dr. Clayton Cone

Basically as budding occurs, the new generation of yeast needs oxygen. Oxygen in trace amounts will not slow or stop the anaerobic cycle, but will in fact help the yeast to ferment more rapidly and aggressively. Also of note is that during the aerobic and the early anaerobic phase of fermentation the yeast will produce up to and above 30 times the amount of ethanol that will be produced in the rest of the fermentation. This in the presence of oxygen, especially during the first 72 hours of fermentation. Hence, oxygen will not slow, stall, impede or otherwise muck up the works for a good strong anaerobic ferment after most of the alcohol has been produced in the early stages.

Hope that helps,

Oskaar

WorkSpace
06-01-2008, 05:25 PM
Medsen, Dan, Oskaar, thanks for the great info. The process is a lot more compicated than I thought, but I am getting the general idea. I think I will apply this newfound knowledge to making wine as well. In the past, I haven't aerated after pitching the yeast, and it takes more than a month for the ferments to complete. So I will be using your method with next wine batch too ... ;)

Earendil
06-01-2008, 07:48 PM
As for the aeration, there have been good studies in wine that explain the need for aeration/oxygen. The oxygen stimulates the yeast to form more sterols that strengthen the cell membrane, allow for more efficient division, promote increased tolerance to alcohol, and allow nutrients to be taken in and utilized late in the fermentation. Completely anaerobic fermentation results in lower amounts of sugar utilization unless the must is supplemented with sterols and long chain fatty acids. Allowing air will actually speed the fermentation. For meads it seems to work the same. Pitching more yeast will not make them stronger or more alcohol tolerant. In wine, oxygenation on day 2 of fermentation seems to be the critical window, but typically folks here will aerate during the first 2 or 3 days - or up to the point that the gravity has dropped by 1/3 (the 1/3 sugar break).




I am so thankful to have found this site, already! I have made all of mine with one heavy oxygenation at the time to pitching yeast. I learned from Ken Schramm's book and he instructs the reader to vigorously shake and then lock. I can't find any advice in the book regarding subsequent aeration (I may have missed it, but have re-read it a couple of times). I'm so glad to find this out! I'm starting two batches today and will repeatedly aerate.

I have a question regarding this: when you say "folks here will aerate during the first 2 or 3 days - or up to the point that the gravity has dropped by 1/3 (the 1/3 sugar break)", does that mean that the Specific Gravity drops by 33 of the 100 points that it 'ideally' should drop during fermentation? Or is it 1/3 of something else?

I expect that the 33/100 is right (it's certainly logical), but having missed out on what now seems so glaringly obvious and sensible a technique makes one a bit cautious. I'd rather ask a 'silly' question than miss the information ...

Thanks Again, both to Workspace for asking the question and for so many others for answering it!


Earendil

Oskaar
06-01-2008, 10:29 PM
Earendil,

For simplicity sake if your mead starts out with a brix of 30 take that number and divide it by three, which equals 10 (aka 1/3 or 33%) Then subtract that from the total to get the 1/3 sugar break.

e.g. 30 brix starting divided by 3 = 10 (30/3=10) then to determine the 1/3 sugar break, Original brix - one-third brix (30-10=20) so 20 brix is your 1/3 sugar break, and then 10 brix would be your 2/3 sugar break.

That's why I work mostly in brix, I hate decimals!

Cheers,

Oskaar

wayneb
06-01-2008, 11:33 PM
But if you're like me and hate to convert between SG and Brix even more than working with decimals, :D then you are correct, Earendil. For the purpose of determining the 1/3 sugar break, take your starting SG, then subtract from that the SG that you expect to end up with when all fermentable sugars are gone (actually, although most totally dry meads end up at slightly less than the SG of plain water, using 1.000 - the SG of water - is close enough for most purposes). That gives you the total change in SG that will occur during fermentation. Take 1/3 of that result, and subtract that from your original SG. The result will be the SG at your 1/3 sugar break.

Here's an example: For a starting SG of 1.126, assuming the mead would be at 1.000 after all the sugars are gone, the total change in SG is 0.126. Take 1/3 of that, which turns out to be 0.042. Subtract that from the original SG: 1.126 - 0.042 = 1.084. 1.084 is the SG at your 1/3 sugar break!

... and your question is not at all silly! :cheers:

Earendil
06-02-2008, 12:17 AM
Ah; I understand. I haven't used Brix, yet; I saw the Specific Gravity and % Potential Alcohol and just started using them. Is there a benefit to using Brix?

I am so glad to have gotten all of this great info! I'm mixing my next must right now; I love that moment when one can put new knowledge to work and this is that moment. Again, my thanks to you all.

I have two meads in fermentation now; one of Brazilian Tropical Flower and one of Pumpkin Blossom. I also have enough of the Pumpkin Blossom honey to make another batch, so I'm going to do that and compare the fermentation, flavor, etc. between the one-shake batch and this one.

I have a related question. I've been fermenting in a 60˚ to 65˚ environment. I've seen various recommendations from 60˚ (Schramm) to 75˚ (Papazian). Which (if any) is better? During the reproductive phase, is it beneficial to have a warmer or cooler environment?

Medsen Fey
06-02-2008, 09:21 AM
Hello Earendil,

Ideal fermentation temperature will vary depending on the individual yeast's tolerance and the specific recipe, but as a general rule, the lower end of the yeasts temperature range is usually the better place to be. I think cooler fermentations preserve more aromatic elements.

Oskaar posted the Pros and Cons of temperature (http://www.gotmead.com/forum/showthread.php?t=10671&highlight=high+temperature+fermentation)in another thread.

If you use the Search Tool (http://www.gotmead.com/forum/search.php)(highly recommended), you can find several other discussions of temperature along with answers to many other questions as they develop.

Good meading!
Medsen

Earendil
06-02-2008, 12:06 PM
Thanks; will do!

Earendil

Oskaar
06-02-2008, 09:36 PM
But if you're like me and hate to convert between SG and Brix even more than working with decimals, :D then you are correct, Earendil. For the purpose of determining the 1/3 sugar break, take your starting SG, then subtract from that the SG that you expect to end up with when all fermentable sugars are gone (actually, although most totally dry meads end up at slightly less than the SG of plain water, using 1.000 - the SG of water - is close enough for most purposes). That gives you the total change in SG that will occur during fermentation. Take 1/3 of that result, and subtract that from your original SG. The result will be the SG at your 1/3 sugar break.

Here's an example: For a starting SG of 1.126, assuming the mead would be at 1.000 after all the sugars are gone, the total change in SG is 0.126. Take 1/3 of that, which turns out to be 0.042. Subtract that from the original SG: 1.126 - 0.042 = 1.084. 1.084 is the SG at your 1/3 sugar break!

... and your question is not at all silly! :cheers:



LOL, no conversion necessary if you use brix hydrometers, I only speak specific gravity here on the forums, everything I do is by brix in the Meadworx.

Cheers,

Oskaar

wayneb
06-02-2008, 10:54 PM
LOL, no conversion necessary if you use brix hydrometers, I only speak specific gravity here on the forums, everything I do is by brix in the Meadworx.

Cheers,

Oskaar


Yeah, well call me "old fashioned!" :laughing7: I still use my old hydrometers (older than many of you here on the forum), and they don't know from Brix! :laughing4:

Oskaar
06-02-2008, 11:56 PM
Yeah, well call me "old fashioned!" :laughing7: I still use my old hydrometers (older than many of you here on the forum), and they don't know from Brix! :laughing4:


Hahaaaa!

Betchya my brix hydrometers are older than you!

Cheers,

Oskaar

Teufelhund
06-03-2008, 10:34 AM
HEY! An OZZY! :laughing7: Welcome to GotMead?!

How many times you been married?? :laughing4:

:cheers:

DD



But I decided to "just do it". I don't like thinking too much before trying something new

wayneb
06-03-2008, 11:03 AM
Yeah, well call me "old fashioned!" :laughing7: I still use my old hydrometers (older than many of you here on the forum), and they don't know from Brix! :laughing4:


Hahaaaa!

Betchya my brix hydrometers are older than you!

Cheers,

Oskaar


Yeah, but that's because they're European. ;)

Oskaar
06-03-2008, 01:36 PM
Yeah, but that's because they're European. ;)


LOL, tomAto tomAAHto.

Cheers,

Oskaar

Earendil
06-03-2008, 08:39 PM
I have another question about aeration. It occurred to me that shaking has to be relatively inefficient; for one thing, the air in there is already mostly CO2, so not much real oxygenation is taking place. For another, I can't really agitate an 80# carboy as thoroughly as one might want. And I don't want to blow new air into the headspace for obvious reasons.

A fellow at my local brew supply store suggested I use a tank of oxygen, a wand and a diffusion stone. He said that I could take a must to its maximum ability to hold oxygen in this way in about 20-30 seconds each time. He has a tank (about 15" high) that he filled over a year ago. He has made over 20 batches of beer with it and it is still far from empty. He didn't know about mead, though he suspected that the requirements would be about the same.

I had read a posting on this site by someone (might have been Oskaar) who used an aquarium pump to pump air through the must to aerate it. The fellow at the brew-store said that this would be largely self-defeating, as the nitrogen in the air would scrub much of the oxygen out of the must as it travels through it.

I've browsed about 400 postings and read nearly 100 posts, on this site, that relate to aeration/oxygenation, but few that address the use of pure oxygen and fewer by those who use the technique. This method seems, in theory, like far and away the best way to aerate, but I'd like to get the opinions of other meadmakers who have used this method. Do you feel it is superior to other techniques? Any noticeable difference in quality of product? Convenience? Expense? How long does a tank of oxygen last?

Thanks!

nbagshaw
06-03-2008, 10:33 PM
One thing I've learned about meadmaking is to have fun and enjoy the process as much as the end result.

Reading the posts I've come to the relization I'm not alone.....girls & pool parties, dynamiting trout...

In that vein, I think I'll aerate my next mead with a trip to Busch Gardens and a ride on the fastest roller coaster.
That's not the travelocity gnome, that's CarboyMan!

wayneb
06-04-2008, 12:43 AM
Earendil, I'll defer to Oskaar on this one. I've not used a pure O2 injection in any of my meads. Not because I'm inherently against it (although I think that I'd like to see someone do quantitative studies on homebrew-sized batches before I'll be convinced that it is significantly more efficient than my air through an airstone technique), but mostly because I don't have the funds to invest in the hardware to try it myself.

Oskaar
06-04-2008, 01:32 AM
I have another question about aeration. It occurred to me that shaking has to be relatively inefficient; for one thing, the air in there is already mostly CO2, so not much real oxygenation is taking place. For another, I can't really agitate an 80# carboy as thoroughly as one might want. And I don't want to blow new air into the headspace for obvious reasons.

A fellow at my local brew supply store suggested I use a tank of oxygen, a wand and a diffusion stone. He said that I could take a must to its maximum ability to hold oxygen in this way in about 20-30 seconds each time. He has a tank (about 15" high) that he filled over a year ago. He has made over 20 batches of beer with it and it is still far from empty. He didn't know about mead, though he suspected that the requirements would be about the same.

I had read a posting on this site by someone (might have been Oskaar) who used an aquarium pump to pump air through the must to aerate it. The fellow at the brew-store said that this would be largely self-defeating, as the nitrogen in the air would scrub much of the oxygen out of the must as it travels through it.

I've browsed about 400 postings and read nearly 100 posts, on this site, that relate to aeration/oxygenation, but few that address the use of pure oxygen and fewer by those who use the technique. This method seems, in theory, like far and away the best way to aerate, but I'd like to get the opinions of other meadmakers who have used this method. Do you feel it is superior to other techniques? Any noticeable difference in quality of product? Convenience? Expense? How long does a tank of oxygen last?

Thanks!




You'll find that LHBS folks who aren't mead makers by preference are for the most part reguritating information they heard from someone else without testing it for themselves.

Bottom line is that you can read and read and read until you pass out. The best way to determine what works best for your purposes is to try each method for yourself. I've used aquarium pumps with great effect and produced excellent meads using that method. I've also used pure O2 through a diffusion stone as well which worked out really nicely too. Honestly, neither of them is any better than using a lees stirrer to WTC out of your must during the first 1/3 of fermentation in my experience. If someone is telling you that one way is the best way I'd be surprised if they weren't telling you what their personal preference is as opposed to what the facts are.

Hope that helps,

Oskaar

PS, My opinion is that a lees stirrer will kick ass on a pure oxygen infusion. My ferments run as short as 5 days to as long as 14 days. Ask your LHBS guy how long his run.

Cheers,

Oskaar

wayneb
06-04-2008, 11:30 AM
PS, My opinion is that a lees stirrer will kick ass on a pure oxygen infusion. My ferments run as short as 5 days to as long as 14 days. Ask your LHBS guy how long his run.

Cheers,

Oskaar


Yeah! My contention is that the must can only hold O2 to a certain equilibrium when in solution in the must; any more will just percolate out to the atmosphere very quickly. So once you've incorporated as much as you can get in via mechanical methods (lees stirrer or aquarium pump), any more won't stay in the must long enough to be of any use. So "pure" O2 sounds like it should be better than room air (after all, high tech is sexy!!), but unless you know that what goes into the must stays in the must, it can't be expected to be demonstrably better than the low-tech methods.

Earendil
06-04-2008, 01:10 PM
It's a good thing I love the learning of new things; now I have to find out what a lees stirrer is, what 'WTC' stands for (though I can make a rough guess), etc.

wayneb, I can see the validity of the idea that the must can only hold so much gas, but it seems to me (again, all in theory) that 1) if you're going to infuse gas into a liquid and 2) if the liquid can only hold so much gas and 3) if what you want is oxygen in there, it would make sense (theoretically) to infuse it with pure oxygen; otherwise about 80% of the gas that is in the must is actually nitrogen, CO2 and trace gases.

I'm curious about the lees stirrer. It sounds like it agitates the lees at the bottom of the carboy and that mental picture doesn't suggest the introduction of fresh air/oxygen into the must. I want to ask a bunch of questions, but I'll school myself to patience and do some research.

First, I'm going to find out what a lees stirrer is and how it works. But being an equipment wonk, I may try the pure-O2 thing, side-by-side with an identical must using the 'KC and the Sunshine Band' technique (shake, shake, shake ...) and see how they compare.

I have to say, after meadmaking all by myself, all this time, it's a real pleasure to find and hobnob with all of you. I've learned a lot in the last 3 days ...

Thanks!

WorkSpace
06-04-2008, 07:23 PM
.... being an equipment wonk, I may try the pure-O2 thing, side-by-side with an identical must using the 'KC and the Sunshine Band' technique (shake, shake, shake ...) and see how they compare. ...

Are you going to try the olive oil trick? By all accounts, it replaces aeration, and there is no risk of contamination. Maybe you could make it part of your controlled test :icon_scratch: .

wayneb
06-04-2008, 08:17 PM
wayneb, I can see the validity of the idea that the must can only hold so much gas, but it seems to me (again, all in theory) that 1) if you're going to infuse gas into a liquid and 2) if the liquid can only hold so much gas and 3) if what you want is oxygen in there, it would make sense (theoretically) to infuse it with pure oxygen; otherwise about 80% of the gas that is in the must is actually nitrogen, CO2 and trace gases.



I can see why you might think that, but in actuality unless there is a pure O2 gas blanket immediately above the must, all the dissolved gas constituents in the must will naturally disperse to an equilibrium that is similar in relative composition to the partial pressures of the constituent gases in the atmosphere, pretty quickly. There is no evidence that extra O2 stays in the must for very long. How quickly do we getr back to a "room air" equilibrium? Well, I don't know the answer to that without being able to conduct an experiment, but the anecdotal evidence from those of us who only introduce atmospheric air to the must (via either the WTC or forced airstone techniques), strongly suggest that it is quick enough that there is no significant benefit derived from using the pure O2. I haven't heard of anyone using O2 infusion getting faster fermentations than Oskaar or I do, nor do they report better ETOH tolerance, nor any other significant differences in any of the other measures of fermentation kinetics.

And yes, WTC stands for what you might think it does -- "Whip the C&@% out of it!" ;)

Also, using a lees stirrer nearer the surface of the must will force a lot of liquid exposure to the gas above it, since it gets the must spinning around at a pretty good clip. When I do WTC, I use a large (12") stainless steel wire whisk, only because I like the forearm workout that I get as a side benefit! The lees stirrer technique is the most efficient mechanical means of forcing exposure to the room air that I've seen. It is even better than the aquarium pump. I only use the pump/airstone method before I've pitched yeast, because I can set it and walk away from it for 30 mins or so as I prep and then rehydrate yeast to ready it for pitching. After fermentation starts I'll either use my whisk or a lees stirrer, depending on my mood. :cheers:

So, yeah, my argument is anecdotal. But I like a good anecdote from time to time! :laughing7:

Earendil
06-06-2008, 05:32 PM
Hmm ... so in theory, if one wanted to make the most of 'oxygen therapy', you'd want to fill the headspace with oxygen as well.

I'm using WTC, right now, and I'm not unhappy doing so; I'm glad to understand some of the techniques, perspectives and trade-offs.

Thanks to All,


Eärendil

Earendil
06-06-2008, 05:53 PM
.... being an equipment wonk, I may try the pure-O2 thing, side-by-side with an identical must using the 'KC and the Sunshine Band' technique (shake, shake, shake ...) and see how they compare. ...

Are you going to try the olive oil trick? By all accounts, it replaces aeration, and there is no risk of contamination. Maybe you could make it part of your controlled test :icon_scratch: .


Wow; sorry I didn't catch this; I never heard of this technique. How in the world can you get oxygen into your must through a film of olive oil? (or at least that's the picture that 'olive oil trick brings to my mind!)

Now I have another thing to research!


Eärendil

Medsen Fey
06-06-2008, 06:17 PM
There is a very interesting thread discussing Olive Oil Here (http://www.gotmead.com/index.php?option=com_smf&Itemid=412&topic=5977.0).

WorkSpace
06-07-2008, 01:06 AM
... After assembling and sterilising the fermenter, I poured the honey into it and added water to 4 litres. I also added some potassium bisulfite, presumably to inhibit bacteria growth. I stirred it well and took a hydrometer reading, which was about 1.075. Tomorrow I will add the other ingredients, being an acid mix, tannin, nutrient salts and vitamin B. After rehydrating it, I will pitch the yeast (Lalvin EC1118).
By way of an update, I didn't add the acid before fermentation, and I gave the must a good stir to aerate it every day during the first 72 hours. I took a hydrometer reading on day 3, expecting gravity to have fallen by a third. I based that expectation on comments I had seen here. But I was only doing a 4 liter batch, and I had used the standard packet of yeast. So fermentation was a lot quicker than I expected it to be. The aeration no doubt helped, and by day 3 the SG had dropped by two thirds to about 1.020. That was three days ago. SG is now about 1.000, and it tastes fairly dry.

I will leave it for a few more days to see if it the hydrometer reading drops any further. I want to get it as dry as possible. Then I will rack to a glass demi-john and I guess I should add the acid blend, although 3 teaspoons sounds like a lot for a 4 litre batch. What do you think? And do you use potassium-bisulfite at this stage?

Oskaar
06-07-2008, 02:58 AM
OK, I'm going to ask you to give us a quick update on how it tastes before you add the acid.

Remember, gluconic acid is a key flavor ingredient in honey, and in most cases one doesn't need to add acid, even at the end. So, let us know how it tastes. I'm probably going to ask that you let this stand and clear before you add any acid. Bottom line is that I haven't added any acid to my dry meads in a very long time, and it's enirely probable that you won't need to either. Remember, the acid additions were old brewer, and even older historical additions based on simple ignorance of how yeast worked, and what mead did and didn't need. A lot of wine drinkers contend that mead is not acidic enough. Mead is from honey, not from grapes, so the additional acid in many cases is based on a non-existant fault from critics who are judging mead as a wine or beer. Evaluate it for what it is, and if you feel you need more acid after it has aged and matured, then you'll be better off adding the acid just before you bottle.

Hope that helps,

Oskaar

WorkSpace
06-09-2008, 05:55 PM
... in most cases one doesn't need to add acid, even at the end. So, let us know how it tastes. ...

Thanks for that Oskaar. I tasted it last night, and I don't think adding acid would improve it. The person who gave me the recipe told me that the acid was needed to to protect from infection. Is there any merit in this? Anyway, the hydrometer reading hadn't changed in three days, so I racked to a glass demijohn. It was quite fizzy. Do you add anything to help it clear? And how long should I expect it to take?

WorkSpace
06-28-2008, 10:44 PM
To refresh your memory, I made an initial 4 litre batch with 1 Kg of clover honey and some tannin - thats all. After fermentation finsihed, I added some bentonite and the mead cleared quickly. After 2 weeks, it was as clear as white wine, so I have bottled it. My wife thought it was dreadful, but I thought it may have promise. Beer and wine doesn't taste like much when it is bottled either. It tasted it very dry (which is what I wanted), but it was lacking flavour I thought, and it was a bit rough. Will it improve with time, do you think? And how long should I wait before opening a bottle?

wayneb
06-28-2008, 11:50 PM
It will very likely improve with age. I would give it at least 6 months before you try another bottle, and keep them stored in a place that will keep the temperature as close to constant as possible.