PDA

View Full Version : Rehydrating Your Yeast



Fred Bee
06-21-2011, 10:49 PM
Greetings all...this is my first post here on the forum. Just recently started making one gallon batches of mead. My last batch was a pear melomel. Now to my question...

I was told that when you rehydrate your yeast (prior to pitching) that you should open the pack of yeast (Lalvin D47) and add to a small bowl of warm water about 94 degrees and let it set for 15 minutes prior to pitching. This is what I have done. However, I was also told the yeast would start getting active and bubbly prior to pitching. In my case, I have not noticed much action with the yeast getting bubbly in the small bowl prior to pitching.

That said, after pitching my yeast into the mead, within the next 24 hours every batch seems to be chugging along nicely. So, the yeast is obviously actively working and doing its thing. All this said, I suppose my question is, do I need to do anything differently to rehydrate my yeast? Or...is it as simple as adding it to the warm water - waiting 15 minutes and pitching it in? Thanks in advance for your help and advice.

wildoates
06-22-2011, 12:51 AM
Yep, most of us add Gro-Ferm to the water when hydrating the yeast. Works a treat as far as I can tell. :)

wildoates
06-22-2011, 12:52 AM
Oh, and welcome to Gotmead!!!!

YogiBearMead726
06-22-2011, 01:56 AM
Also, try having the warm water at 104F next time, not 94F. Something else that some people like to do (not necessary, but is an easy additional step) is to add some of the must you want to ferment into the rehydration vessel. That should give you active bubbling before pitch.

Otherwise, just rehydrate in some warm water, wait 15 min, then pitch.

And welcome to GotMead! ;D

Chevette Girl
06-22-2011, 03:33 PM
Heathen that I am, I usually just dry-pitch (sprinkle directly from the packet on top of the must) unless it's a high-gravity must (more than 3.5 lb of honey in a gallon of water or SG above 1.120). And when I rehydrate with water, I don't usually see/smell activity with wine yeast the way I do with bread yeast.

Welcome, and how did your pear mel turn out? Others on this forum seem to think pear's a very subtle flavour but I ferment something with pears every year and mine always seem to come out pretty dominantly pear flavoured.

AToE
06-22-2011, 05:32 PM
Something else that some people like to do (not necessary, but is an easy additional step) is to add some of the must you want to ferment into the rehydration vessel. That should give you active bubbling before pitch.



Just for clarification, this must is added after 15 minutes of rehydrating in just water, or water and goferm, then you let it sit for a while (10 minutes, whatever) and pitch that. This gets your yeast ready for the temperature and sugar content of the must.

I personally often do this in two steps, 15 minute rehydration, add about a cup of must, wait 10 minutes, add another cup, 10 minutes, then pitch. Sometimes even more steps.

I never really see the yeast apear to be active when rehydrating them until I add the must.

YogiBearMead726
06-22-2011, 07:18 PM
Just for clarification, this must is added after 15 minutes of rehydrating in just water, or water and goferm, then you let it sit for a while (10 minutes, whatever) and pitch that. This gets your yeast ready for the temperature and sugar content of the must.

I personally often do this in two steps, 15 minute rehydration, add about a cup of must, wait 10 minutes, add another cup, 10 minutes, then pitch. Sometimes even more steps.

I never really see the yeast apear to be active when rehydrating them until I add the must.

Ah, yes. Thanks for clarifying the time schedule for that. :)

Fred Bee
06-22-2011, 09:49 PM
Thanks all for your helpful comments. I appreciate learning more about this and how others prepare their yeast prior to pitching. Chevette Girl...in response to your question about my pear melomel, it is not far enough along to be ready for tasting just yet...but when I do, perhaps I can report on how it came out.

mccann51
06-22-2011, 11:15 PM
Just for clarification, this must is added after 15 minutes of rehydrating in just water, or water and goferm, then you let it sit for a while (10 minutes, whatever) and pitch that. This gets your yeast ready for the temperature and sugar content of the must.

I personally often do this in two steps, 15 minute rehydration, add about a cup of must, wait 10 minutes, add another cup, 10 minutes, then pitch. Sometimes even more steps.


Have you noticed a reduction in lag time?

Oskaar
06-23-2011, 02:03 AM
Okay folks, let's not forget to mention that you need to stir the yeast until there are no clumps whatsoever left in your yeast slurry.

Rehydrating your yeast works better when you have the yeast in a clean and sanitized mixing vessel and you add the 104F water to it rather than adding the dry yeast to standing water. Just think of hot cocoa, instant soup or bouillon. It blends and dissolves easier that way.

You want to stir the be-jeezus out of it until there are no clumps, and no undissolved yeast in your mixing vessel. Then let it sit for 15 minutes and stir again, then let it sit for 5 minutes. Once the 5 minutes are up, add an amount of your must equal to twice (2X) the amount of your yeast slurry.

So if you have a 200 ml yeast slurry, you add 400 ml of the must, then stir and allow to stand for 5 more minutes. If there is a temperature difference between your must and your yeast slurry of 18F or greater you will need to do an atemperation step for each 18F degree difference until the must and the slurry are less than 18F apart in temperature.

If you follow the instructions and are careful about checking your temperatures and making sure your yeast is fully dissolved before letting it rest between steps, your fermentation will take off like a rocket.

Cheers,

Oskaar

AToE
06-23-2011, 02:14 AM
Nice, thanks Oskaar, that's good refinement on my current process, I'll follow that from here out.

mccann51 - no, I haven't noticed a specific decrease in lag time. My lags are generally all over the place, usually between 1-4 hours, sometimes as much as 12 in a mead. I haven't been acclimatizing the rehydrated yeast for long enough/enough batches yet to really be able to say for sure it's decreasing lag.

It's one of those things though, even if my observations don't tell me it's helping, scientifically I know it is so I'll do it - also, I don't generally expect big changes in my product from any one new step or process, each one is just another brick in the wall, when I add 15 new techniques all together I can definitely see my meads improve (generally I see the improvement in how early it's drinkable, and how truely "clean" it is once it's aged).

Oskaar
06-23-2011, 02:25 AM
Happy to help.

Also, just a quick note. When I make wine I have yet to wait the entire 5 minutes after I add the must to the slurry. The reason is the yeast is already taking off and the resultant bubbling and CO2 production will boil over the top of the vessel.

I pitch that foaming, rabid, frothy, growing slurry into the the must and it is like watching a kettle start to boil!

Cheers,

Oskaar

Chevette Girl
06-23-2011, 03:00 AM
When I make wine I have yet to wait the entire 5 minutes after I add the must to the slurry. The reason is the yeast is already taking off and the resultant bubbling and CO2 production will boil over the top of the vessel.


More evidence that yeast love grapes but have a harder time with honey? ;D

Your yeast are far more vigorous than mine, mine generally get the job done in good time but I don't think I've ever had a wine yeast get that excited about any must, maybe there's something to this 'goferm' stuff :)

Loadnabox
06-23-2011, 08:37 AM
Oskaar,

I'll definitely give this a try next time.

I'm very curious about the deviation. Directions on a pack of Lallevin yeast say NOT to stir until the 15 minutes are up, then stir it all into suspension.

Any word on why it is better to pre-stir it up?

Chevette Girl
06-23-2011, 08:46 AM
In my experience, if you sprinkle it on top of your rehydration water, the Lalvin yeast just spreads out on the top and doesn't clump unless you stir it, which is probably why they recommend against.

Matrix4b
06-23-2011, 10:55 AM
The way that I do my yeast is:

I pull out a plastic cup, put 1/4 room temp water and put 1/4 of my hot must, or rather warm must. Then I put in my yeast and stir with a sanitized spoon. I then go back to my must and wait about 1 hr for my must to be cool enough to toss the yeast.

What happens in that time is that the yeast bubbles up and I get about 1/2 a cup of foam. I then toss that in my Must when it is of proper temp to toss the yeast.

The reason why you get no activity is that the yeast have no sugar to eat. Try puting a teaspoon of sugar and disove it in prior to putting the dry yeast in the bowl. The yeast might be a little starved for nutrients until you put it in the must but it should become active and come back to life.

The reason I use a plastic cup is so that I can toss the cup and so I don't need to sanitize it. Oh, an I put the cups in an empty sink in case of overflow. It has happened once or twice.

Matrix

Loadnabox
06-23-2011, 10:59 AM
The way that I do my yeast is:

I pull out a plastic cup, put 1/4 room temp water and put 1/4 of my hot must, or rather warm must. Then I put in my yeast and stir with a sanitized spoon. I then go back to my must and wait about 1 hr for my must to be cool enough to toss the yeast.

What happens in that time is that the yeast bubbles up and I get about 1/2 a cup of foam. I then toss that in my Must when it is of proper temp to toss the yeast.

The reason why you get no activity is that the yeast have no sugar to eat. Try puting a teaspoon of sugar and disove it in prior to putting the dry yeast in the bowl. The yeast might be a little starved for nutrients until you put it in the must but it should become active and come back to life.

The reason I use a plastic cup is so that I can toss the cup and so I don't need to sanitize it. Oh, an I put the cups in an empty sink in case of overflow. It has happened once or twice.

Matrix



I know that Oskaar has mentioned in the past that Lallevin yeast are intended to be rehydrated in water or water/goferm. I recall reading somewhere that adding sugar to the rehydration can actually decrease the number of viable cells.

Chevette Girl
06-23-2011, 11:06 AM
I know that Oskaar has mentioned in the past that Lallevin yeast are intended to be rehydrated in water or water/goferm. I recall reading somewhere that adding sugar to the rehydration can actually decrease the number of viable cells.

Yeah, it's simple science, the yeast are dehydrated so you need to rehydrate them with water BEFORE you feed them sugar, otherwise there is an osmotic effect which will tend to pull the water OUT of the yeast at higher sugar concentrations (like drinking straight honey to rehydrate yourself - yeah, there's some water in there but drinking it when you're dehydrated is the opposite of help, whereas the goferm would be like adding some Gatorade powder to your water to help rehydrate you). When I make a starter for a high-gravity must, I give my yeasties 15 min in their 1/4 cup of water, then I add 1/4 cup of must and double it every time I see a little activity (20 min-2 hours depending on the situation) till I have a nice amount of happily frothing must. I've just never had it foam up like crazy even after leaving it overnight.

Medsen Fey
06-23-2011, 11:29 AM
Some studies have shown a small amount of sugar (like 50 g/L) in rehydration solution may be helpful.

TheAlchemist
06-23-2011, 04:06 PM
Guess I just don't have enough Virgo in my chart...Sometimes I just throw the dry stuff on top of the must and see what happens...if it takes a little longer to get going, that's OK with me.

chams
06-23-2011, 05:31 PM
Okay folks, let's not forget to mention that you need to stir the yeast until there are no clumps whatsoever left in your yeast slurry.

Rehydrating your yeast works better when you have the yeast in a clean and sanitized mixing vessel and you add the 104F water to it rather than adding the dry yeast to standing water. Just think of hot cocoa, instant soup or bouillon. It blends and dissolves easier that way.
Oskaar

The Lalvin packets I use clearly state to dissolve the yeast in the rehydration vessel, wait 15 minutes without stirring, then stir to suspend the yeast and pitch.
That said, I'm like Chevette Girl. Sometimes I just pitch right on top of the must. :)

AToE
06-23-2011, 05:51 PM
The Lalvin packets I use clearly state to dissolve the yeast in the rehydration vessel, wait 15 minutes without stirring, then stir to suspend the yeast and pitch.
That said, I'm like Chevette Girl. Sometimes I just pitch right on top of the must. :)

This has come up before, I remember a discussion between Oskaar and one of the other senior members, can't recall who, about this issue specifically: whether it's better to stir immediately or wait until after rehydration.

I think the idea behind waiting is that the cell walls are still very weak at the beginning of the rehydration process, but there was a good counter argument to this as well.

It's probably a case of old information (don't stirr at beginning) compared to new information I'm thinking? Or it's just a case of differences of opinion, I can't honestly remember how that conversation finished.

EDIT: Just thought of this too: Lalvin might be more warning people away from stirring during rehydration, whereas what Oskaar is talking about is just the dissolving process right at the beginning, maybe as this is before the rehydration really begins it doesn't do whatever Lavlin is worried about stirring doing?

Oskaar
06-23-2011, 05:59 PM
More evidence that yeast love grapes but have a harder time with honey? ;D

Your yeast are far more vigorous than mine, mine generally get the job done in good time but I don't think I've ever had a wine yeast get that excited about any must, maybe there's something to this 'goferm' stuff :)

Part of the reason is something you stated before, and I don't know if you do this for all batches or just some. You mentioned sprinkling the yeast into the must rather than rehydrating it. That's part of the issue. Most dry yeast needs to be rehydrated in clean 104F water for 15 minutes after stirring.

Active Dry Yeast are not designed to flourish when introduced into high sugar solutions. In fact, you will generally kill off a large number of your yeast in doing so. The sugar will get most of them, and then the lower temperature will get even more.

The ideal temperature for hydration is 104F. This represents the best balance between the water being warm enough to maintain an ideal elasticity of the yeasts cell membrane as it is being reformed, while not being too hot so as to start damaging the cell itself. Higher temperatures are definitely not recommended so as to avoid the “poaching” effect, slightly lower ones are acceptable.

When you start to go below 95F there is a phenomenon that happens due to the lack of adequate heat needed to make the cell wall fluid enough to fold back out and reform itself during the critical hydration process. As a result, parts of the cell wall will remain permanently wrinkled and the yeast never fully recover from the folded, crinkled form it took when it was dehydrated.

In the end, the yeast will essentially be mortally damaged and it will eventually die. So, with this in mind, if you can try and target the 104F - 102F range for your hydration water you will be doing both yourself and the yeast a great favor.

Another issue to consider is that the added yeast produces 30+ times as much alcohol per yeast cell during its growth phase than it does during the stationary phase. You can keep it in its growth phase longer by using a proper rehydration nutrient (I like Go-Ferm) addition in order to give your yeasties the best rehydration gradient you can provide. You'll notice that your stationary or "lag" phase will be shorted and your fermentation should be more vigorous and take less time as well.

Hope that helps,

Oskaar

AToE
06-23-2011, 06:06 PM
I might have to do a simple test for myself to see if I can actually observe the improvement in the final product with proper rehydration vs sprinking the yeast into the must (which I've never done). Theoretically a happy yeast produces less off characterists than a stressed one, so the mead should be better.

Of course one test would hardly be even remotely conclusive.

Loadnabox
06-23-2011, 06:25 PM
The ideal temperature for hydration is 104F.

Hope that helps,

Oskaar


Very interesting....

I've always gone with what the packet says which is between 104-109Fi often adding the yeast at the higher end (108-109)

As usual Oskaar I bow to your knowledge :)

Fred Bee
06-23-2011, 11:51 PM
Well, it sounds like I need to start rehydrating my yeast in warmer water than what I have been using. I have been going with 94 degree water instead of 104 degree water. I think I will use warmer water at about 104 degrees next time and will see what happens.

Oskaar
06-23-2011, 11:53 PM
I might have to do a simple test for myself to see if I can actually observe the improvement in the final product with proper rehydration vs sprinking the yeast into the must (which I've never done). Theoretically a happy yeast produces less off characterists than a stressed one, so the mead should be better.

Of course one test would hardly be even remotely conclusive.

No theory involved in this dude. Unhappy yeast produce off-flavors and reductive characters in the wine, mead, and beer. They also manifest as sulfur aromas during the ferment. Many years ago it was theory, but it's now a given in the wine, mead and beer making world.

Hope that helps,

Oskaar

Oskaar
06-23-2011, 11:54 PM
Well, it sounds like I need to start rehydrating my yeast in warmer water than what I have been using. I have been going with 94 degree water instead of 104 degree water. I think I will use warmer water at about 104 degrees next time and will see what happens.

You can get a nice bottle of still mineral water to rehydrate your yeast. The minerals help with rehydration.

Cheers,

Oskaar

Fred Bee
06-24-2011, 12:52 AM
You can get a nice bottle of still mineral water to rehydrate your yeast. The minerals help with rehydration.

Thanks! I have been using spring water, but I may give the mineral water a try.

mfalenski
06-24-2011, 11:59 AM
Rehydrating your yeast works better when you have the yeast in a clean and sanitized mixing vessel and you add the 104F water to it rather than adding the dry yeast to standing water.


And the 104F water has the Go-Ferm already mixed in, if you're using it?

AToE
06-24-2011, 12:15 PM
No theory involved in this dude. Unhappy yeast produce off-flavors and reductive characters in the wine, mead, and beer. They also manifest as sulfur aromas during the ferment. Many years ago it was theory, but it's now a given in the wine, mead and beer making world.

Hope that helps,

Oskaar

I'm a science type fellow, when I say "theory" I mean "fact" ;) - where most people use "theoretically" to mean "guess" I'd use "hypothetically". ;D

So yes, I know! I'm just curious to see to what degree it will manifest. Also good to note I have so many test batches planned that I'd be getting to this one in a few years, if ever... more likely never since it's one I already know roughly what to expect.

Oskaar
06-24-2011, 01:38 PM
I'm a science type fellow, when I say "theory" I mean "fact" ;) - where most people use "theoretically" to mean "guess" I'd use "hypothetically". ;D

So yes, I know! I'm just curious to see to what degree it will manifest. Also good to note I have so many test batches planned that I'd be getting to this one in a few years, if ever... more likely never since it's one I already know roughly what to expect.

I hear ya! LOL

mccann51
06-24-2011, 08:27 PM
You can get a nice bottle of still mineral water to rehydrate your yeast. The minerals help with rehydration.

Cheers,

Oskaar

My understanding was that tap water served the same purpose, though I guess a municipality's water quality could be prohibitive to this approach.

Riverat
06-24-2011, 09:16 PM
My understanding was that tap water served the same purpose, though I guess a municipality's water quality could be prohibitive to this approach.

The general concerns with tap water are probably more along the line of what was needed to treat it to drinking quality, chlorine being the most common thing you don't want in your stuff, no doubt there are others.

wayneb
06-24-2011, 11:50 PM
And the 104F water has the Go-Ferm already mixed in, if you're using it?

Yes, Matt. Typically when I am rehydrating yeast I will start with water at 110F, then add the Go-Ferm, and then when that slurry is well mixed I'll add my dry yeast. If you're using the recommended ratio of water to Go-Ferm and your Go-Ferm is at normal room temperature, the slurry will be right about at 104-105F and ready for your yeast to be pitched.

Now we do need to note that the 104-109F temperature range is what Lallemand recommends for their yeast. I know that LeSaffre (Red Star) recommend some slightly different temperatures for some of their strains, and many ADY beer strains are even different from that. Always follow the yeast manufacturer's recommendations for rehydration temperature, because if they have properly done their jobs they have tested for viable cell counts as a function of temperature, and they should be giving you the ideal range for their particular product.

Chevette Girl
06-25-2011, 01:10 AM
Part of the reason is something you stated before, and I don't know if you do this for all batches or just some. You mentioned sprinkling the yeast into the must rather than rehydrating it. That's part of the issue. Most dry yeast needs to be rehydrated in clean 104F water for 15 minutes after stirring.

Active Dry Yeast are not designed to flourish when introduced into high sugar solutions. In fact, you will generally kill off a large number of your yeast in doing so. The sugar will get most of them, and then the lower temperature will get even more.


[FONT="Arial"]If it's less than about 1.110 I sprinkle (every wine kit I've ever used contains Lalvin yeast and each one has advised to sprinkle), between that and 1.120 I rehydrate in warm water (body temp) and if it's above 1.120 I make a starter by adding small amounts of must.

Thank you for the information on how important temperature is though, I didn't know that, I just always used warm water because it works for bread yeast :)

Oskaar
06-25-2011, 02:48 AM
My understanding was that tap water served the same purpose, though I guess a municipality's water quality could be prohibitive to this approach.


You'll need to check your chlorine and chloramine levels before you can rely on your tap water. This information should be available in your municipal water report.

Cheers,

Oskaar

Oskaar
06-25-2011, 03:08 AM
If it's less than about 1.110 I sprinkle (every wine kit I've ever used contains Lalvin yeast and each one has advised to sprinkle), between that and 1.120 I rehydrate in warm water (body temp) and if it's above 1.120 I make a starter by adding small amounts of must.

Thank you for the information on how important temperature is though, I didn't know that, I just always used warm water because it works for bread yeast :)

This doesn't surprise me. Remember that the wine kit is made by different folks than the ones who manufacture the yeast, and they don't necessarily have a clue about the needs of the yeast based on the manufacturer's spec.

See here (http://www.lalvinyeast.com/importance_rehydration.asp) and here (http://www.lalvinyeast.com/faq.asp) for Lalvin's take on yeast rehydration.

Below is some information from Jack Keller's website, http://winemaking.jackkeller.net You'll see references to ADY which is simply Active Dry Yeast.

Yeast Starters
An active culture gets the fermentation up to speed in hours

The preferred method of adding an ADY culture to a must is to add a yeast starter, or activated culture to the aseptic must. This simply means the yeast is introduced to a liquid medium favorable to rapid activation and propagation a day or so prior to adding to the must. The liquid with the activated culture is then added to the must as required, where the yeast culture very rapidly propagates to a desired density.

This method is preferable to adding the ADY culture to the must for several reasons. First and foremost, it results in a rapid fermentation. The flavors, aromas and nuances we want to capture from the must and impart into our wine are often very perishable and dissipate or change within days if not hours. The sooner the yeast can get to work capturing them, the better the resulting wine will be as a result. Adding a starter, as opposed to adding the ADY culture directly from the foil packet, can save one to several days, depending on the yeast strain and the size of the batch of must.

Secondly, it ensures viability of the strain. Normally, when you purchase a sachet of yeast you have no idea how old the ADY culture inside the packet is. Given a constant and acceptable temperature, the culture can survive for years in the foil without detriment. But the foil packets could have been--and probably were--shipped without regard to temperature. The box in which they were shipped could have sat in the sun on the tarmac at Los Angeles International in 110 degrees heat for an hour before being loaded in the plane that took it to your regional airport hub or local point of entry. It was then taken by truck to a transshipment warehouse where it may have dwelled for days in similar heat before being trucked to your city and then to your supplier. If 90% of the culture baked in the process, it will take that much longer for the culture to build to a density conducive to your needs. If 100% of the culture baked, you could easily waste a week discovering that fact, and during that week your must deteriorates and possibly is ruined. By making a stater solution two days before needed, you would have discovered that the yeast was non-viable within a day and still had time to prepare another.

Thirdly, a starter properly made, using water, a small quantity of the must itself or a juice substitute (grape, orange or apple juice) and some nutrients, will acclimate the yeast to its destined environment. When the starter is added to the primary, it will practically explode with activity and do what nature and selection programmed it to do and do it that much more efficiently.

The correct method of making a starter is to rehydrate the yeast, activate its life cycle, and add it to the must. The optimum way to rehydrate the yeast is to add it directly to 1 cup of 100-105-degree F. tap or spring water (the harder the water the better; do not use distilled water). Stir gently, cover, allow to rehydrate for at least 30 minutes, check on it to be sure it is viable, and then leave it another 3 1/2 hours. During this time, allow the starter and must (or fruit juice) to attemperate to within 10 degrees F. of one another, and then add to the starter 1/4 cup of pre-sweetened, reconstituted juice (not pure concentrate) or strained must. Re-cover the starter, set it in a warm place and leave it alone. Check on it 4 hours later to ensure it is viable and add to it another 1/4 cup of juice or strained must. Again, cover and leave it alone for 4 hours. You can now add it to the must or add another 1/2 cup of juice or strained must to really increase the yeast population (at the end of an additional 4 hours, the colony will be approximately 64 times as large as it was when rehydrated). For highly acidic (native grapes) or potentially troublesome musts or juices (like blueberry, peach, or Ribena blackcurrant), the more must you add to the starter, the better acclimated the yeast will be to the conditions they will be living in. There are other methods of starting a culture and most are just as successful, but this method, only slightly varied, was recommended by George Clayton Cone of Lallemand, the makers of Lalvin wine yeasts, and that is good enough an endorsement for me.

Lallemand's scientists found that some musts and juices contain sprays, toxins and excessive SO2 that can be detrimental to the activity of yeast. The dry yeast is like a sponge for the first few seconds in liquid and will absorb everything into the cell that it would normally reject in the rehydrated form. Many home winemakers add the ADY culture directly to the must or juice and get away with it. However, many times it is the beginning of a sluggish or stuck fermentation. There are over 150 billion yeast cells in a 5-gram packet of Lallemand yeast. If you kill off half of them by improper rehydration, you still have 75 billion cells to work with. This 75 billion will go on to do a good job most of the time, but whatever killed off the other 75 billion may have seriously affected the health of the survivors. Can you spell "stuck fermentation?" A little prudence is good insurance.

If you forget to make a starter or simply don't want to, then inoculate the must by sprinkling the ADY culture evenly over the top of the must and DON'T stir it in. Cover the primary and take a peek 12 hours later. If viable, there will be a prominent yeast colony across the surface and evidence in the form of a thin foam and/or a distinctly yeasty smell. Stir it shallowly into the must and 12 hours later stir it deeply. If there is no evidence of the yeast's viability, wait another 12 hours and check again. If still no evidence, inoculate again. Better yet, make a starter. Better late than sorry.

Hope that helps,

Oskaar

Chevette Girl
06-26-2011, 12:50 PM
Looks like "yeast abuse testing" is another one on the To Do list... boy is that list getting long. Maybe it's that I've never found go-ferm, but even when I do make an acclimated starter, I don't get the violent frothing and MEA's some people describe...

And I have had one dead packet of yeast so yeah, now and then you get a dud. I tried multiple times (for a 1-gal batch I use about 1/3 packet so I had enough to sprinkle, then rehydrate, then make a starter, all no go) to get it to do something before I finally either pitched a fresh packet or innoculated it with some of another active ferment.

And I obviously need to get off my lazy butt and do some research about a lot of things I've been mostly ignoring... thanks for the kick! :)

Chevette Girl
06-26-2011, 12:59 PM
You'll need to check your chlorine and chloramine levels before you can rely on your tap water. This information should be available in your municipal water report.


I used to work for my city's water plant, I know that dissolved chlorine will dissipate on its own within a couple of hours left to air, I can't say for sure but I do believe that if you use boiled tapwater, that should get rid of the chloramines, they're pretty hardy but not THAT hardy, and some water testing I did when I tried selling water softeners seems to agree. The chloramine level in my tapwater is supposed to be 1 ppm and I don't know how much dissipates on its trip through the hot water tank if I use warm tapwater, I haven't noticed much difference in how vigorous a starter it makes if I use warm tapwater versus boiled water. And that cursed list gets ever longer.:rolleyes:

I've also got a friend who's convinced that adding a campden tab to water will dissipate the chlorine and chloramine as well but I have done no research on it and can't tell you what chemical reaction that would be...

Medsen Fey
06-27-2011, 12:14 PM
I've also got a friend who's convinced that adding a campden tab to water will dissipate the chlorine and chloramine as well but I have done no research on it and can't tell you what chemical reaction that would be...

Your friend is correct.

See Here (http://www.environmental-expert.com/articles/comparison-of-dechlorination-rates-and-water-quality-impacts-for-sodium-bisulfite-sodium-thiosulfate-and-ascorbic-acid-236157) for some scientific data - you'll note that ascorbic acid (Vit C) can also be used to remove chlorine, but may not remove chloramines.

This page (http://www.jcichem.com/jcipages/prodpgs/SodSulfite.html) describes the reactions and I've cut and pasted the tables below.

Although I don't recall the exact dosing, I believe 1 Campden tablet will treat about 40 gallons of water.

Chevette Girl
06-27-2011, 12:41 PM
Your friend is correct.

Although I don't recall the exact dosing, I believe 1 Campden tablet will treat about 40 gallons of water.

Thanks, Medsen. Your search-fu is stronger than mine, when he first mentioned it I did a cursory search and didn't come up with anything useful.

I think he was using 1 tab for a 5-gal cooler but likely only because cutting them in half is a pain and a little extra won't hurt anything, the amount of dissolved CL2 is quite small so that dosing makes sense... Thanks for explaining the mechanism, it makes a little bit of hydrocholoric acid out of the chlorine. He just told me it converted into yeast food, which sounded hokey to me.

I know our water uses chloramines so I did a bit more poking around and came up with the equation for chloramine, it's just using another step of dissociation of the chloramine in water to get to hydrochloric acid and sodium sulphate, plus the leftover ammonia.

NH2Cl + H2O <-> NH3 + HOCL
NaHSO3 + HOCL <->NaHSO4 + HCL

I guess it still leaves you with a tiny bit of ammonia in solution, which is a problem for an aquarium but likely what he was calling yeast food, since I think they can use that. Not so hokey after all :)

Matrix4b
06-29-2011, 12:09 PM
Yeah, it's simple science, the yeast are dehydrated so you need to rehydrate them with water BEFORE you feed them sugar, otherwise there is an osmotic effect which will tend to pull the water OUT of the yeast at higher sugar concentrations (like drinking straight honey to rehydrate yourself - yeah, there's some water in there but drinking it when you're dehydrated is the opposite of help, whereas the goferm would be like adding some Gatorade powder to your water to help rehydrate you). When I make a starter for a high-gravity must, I give my yeasties 15 min in their 1/4 cup of water, then I add 1/4 cup of must and double it every time I see a little activity (20 min-2 hours depending on the situation) till I have a nice amount of happily frothing must. I've just never had it foam up like crazy even after leaving it overnight.

Hmm, That is interesting. Now from what I have experienced is that it hasn't hurt the yeast. Also, the website posted later says:

"Thirdly, a starter properly made, using water, a small quantity of the must itself or a juice substitute (grape, orange or apple juice) and some nutrients, will acclimate the yeast to its destined environment. When the starter is added to the primary, it will practically explode with activity and do what nature and selection programmed it to do and do it that much more efficiently."

Which is essentially what I am doing, Using mostly water at room temp, the heated Must that I add is usually only about a tablespoons worth for a cup volume. The Must also has my DAP or Yeast Energizer and Yeast Nutrient mixed in at that point. So by te sounds of the website post, I am doing it right. With the exception of the temp. I would have to guess that the resulting temp is about 80F. Ofcourse this is also in Colorado so I don't know that Altitude has any effect. Logically, for oxygen density and boiling temp differing at 5000 ft above sea level should have some effect.

With my method, I always end up with a very dense starter that has foamed up a lot and then calmed down a bit. Never had a dud yeast pack.

So, I don't know. By the sounds of things the initial yeast has time enough to replicate past the crumpled stage and have some starving but very eager and active yeastie beasties.

I am in process of improving my brews though, much thought. I don't do step nutrients, just put it all in at once and let it go, rack at about a month when it slows down. and rack again when clearing with sparkloid if neccessary. I usually do about 3-4 rackings total before I am done, ofcourse I put in the element of oaking, fruit, spices, all on seperate rackings to layer in the flavors. so I don't know.

matrix

Chevette Girl
06-29-2011, 12:32 PM
The Must also has my DAP or Yeast Energizer and Yeast Nutrient mixed in at that point.


Current wisdom suggests that DAP not be included in any rehydration because it can 'burn" the yeasties, many don't even add it until after the lag phase. Although if it's diluted in your must and you don't use much must in your starter it's probably fine. That said, for the last six years I added my DAP to the must right before I dry-pitched the yeast and it doesn't look like it's ever hurt anything.

But again, you never know what final effects may result from early yeast abuse...

Medsen Fey
06-29-2011, 07:29 PM
With Lallemand yeast, it is definitely recommended not to use DAP during the rehydration. During rehydration, the membranes of the yeast are "leaky" and they cannot properly regulate the uptake of ammonium ions. This can lead to toxicity. While the effect of mixing in some must with DAP included will probably be negligible from what you can see with the eye, it may cause lower viable cell counts.

Proper rehydration is important, especially the temp. Below about 90F, the phospholipids of the membrane may crystallize causing damage to the membranes as Oskaar has described. However, there are some companies, like Vintner's Harvest which recommend dry pitching of their yeast. They claim to have data showing this results in the highest cell counts. I have asked them to show me such data, but have received nothing to date. What I can say is that from the published scientific studies on rehydration of ADY, the process folks here are describing has been shown to produce the greatest number of viable cells.

AToE
06-30-2011, 12:51 AM
The way that I look at is this: I'm sure that good, even great, mead can be made with any method, rehydration perfectly, imperfectly, no rehydration at all. But, the science (and experience of many senior mead makers) says that the exact same recipe that makes a good/great mead with dry pitching yeast, would make an even better mead with proper rehydration. I don't find it difficult, expensive, or overly time consuming to rehydrate as best as I can, so that's what I do. Frankly, I find that part of the process one of the more fun parts. :)

Medsen Fey
06-30-2011, 09:04 AM
But, the science (and experience of many senior mead makers) says that the exact same recipe that makes a good/great mead with dry pitching yeast, would make an even better mead with proper rehydration.

That might be stretching it just a bit.
However, properly rehydrated yeast, especially those pampered with appropriate rehydration nutrition like GoFerm (or similar products) that supplies sterols, minerals and amino acids for nitrogen, will be able to achieve greater biomass, will have greater alcohol tolerance, will have a higher chance for complete fermentation, and will have a lower risk of sulfur odors.

If you are not rehydrating and getting great results, that's certainly OK, but if you try a lot of different recipes (especially some of the extreme brews we aim for) you'll run into situations where the proper rehydration will make a difference. I prefer to try to optimize the yeast I pitch in every case.

mccann51
06-30-2011, 11:56 AM
That might be stretching it just a bit.
However, properly rehydrated yeast, especially those pampered with appropriate rehydration nutrition like GoFerm (or similar products) that supplies sterols, minerals and amino acids for nitrogen, will be able to achieve greater biomass, will have greater alcohol tolerance, will have a higher chance for complete fermentation, and will have a lower risk of sulfur odors.

If you are not rehydrating and getting great results, that's certainly OK, but if you try a lot of different recipes (especially some of the extreme brews we aim for) you'll run into situations where the proper rehydration will make a difference. I prefer to try to optimize the yeast I pitch in every case.

To clarify: you're saying if you're producing a good mead by dry-pitching, rehydrating isn't gonna make much of a difference, but rehydrating will mitigate some potential issues (fusels, sulfur, stuck ferments) if other conditions (temp, OG, O2 content) aren't ideal?

Medsen Fey
06-30-2011, 12:52 PM
To clarify: you're saying if you're producing a good mead by dry-pitching, rehydrating isn't gonna make much of a difference,...

That's probably true in most cases. You can certainly run a couple of test batches to see for yourself.

AToE
06-30-2011, 02:08 PM
That might be stretching it just a bit.
However, properly rehydrated yeast, especially those pampered with appropriate rehydration nutrition like GoFerm (or similar products) that supplies sterols, minerals and amino acids for nitrogen, will be able to achieve greater biomass, will have greater alcohol tolerance, will have a higher chance for complete fermentation, and will have a lower risk of sulfur odors.

If you are not rehydrating and getting great results, that's certainly OK, but if you try a lot of different recipes (especially some of the extreme brews we aim for) you'll run into situations where the proper rehydration will make a difference. I prefer to try to optimize the yeast I pitch in every case.

I'm under the impression that less stressed out yeast will simply produce less off flavours and aromas as well (above and beyond obvious flaws like sulphur), so the final product could potentially be cleaner tasting/smelling, and maybe need a little less aging. But, until I do some side by side testing some day I won't really have something in front of me to compare.

Oskaar
06-30-2011, 04:21 PM
To clarify: you're saying if you're producing a good mead by dry-pitching, rehydrating isn't gonna make much of a difference, but rehydrating will mitigate some potential issues (fusels, sulfur, stuck ferments) if other conditions (temp, OG, O2 content) aren't ideal?

To me it's pretty simple. If you don't want to change the way you're making mead, and you're happy with what you have, don't change it.

If you're curious, try something different and check the difference with friends via a blind tasting.

I will say that over the years I have tasted literally hundreds of meads that people viewed as good mead and very, very few of them were actually good. The methods varied but both dry pitching and "pitch and pray" were pretty common to the processes cited. I'd actually go so far as to say that none were great, and I told them so in polite, but no uncertain terms because they asked for an honest evaluation. IMO dry pitching will yield passable mead. I've done it and had passable mead, sometimes I would get a good mead.

If you want consistent high quality mead that ferments clean, matures smoothly, and continues to age and improve, strong, fast, clean and healthy fermentations are key. If you want consistent quality fermentations, you need to rehydrate your yeast. I'm speaking specifically of Lallemand and Lalvin yeast when I say this. There are other manufacturers that recommend other things. Their processes are probably different than Lallemand's, and they probably have a different end product as a result.

Bottom line, use the method recommended by the yeast manufacturer for inoculating your must with their product.

Cheers,

Oskaar

Chevette Girl
07-01-2011, 11:43 AM
Thank you everyone for contributing to this discussion,good stuff to think about all around. This compilation of "why should I change if what I'm doing works" versus "why shouldn't I do the best that I can for my yeast every time" is definitely worth a couple of test batches, especially in light of what Oskaar was saying about good vs great, but I guess it also depends on your palate as well... I think my "taste of abuse" test series will be six 1-gal batches, aiming for 11% and 16% to note the difference between a high-grav and lower-grav pitch, each with pitch and pray, simple rehydration and if I can get my hands on go-ferm I'll try that as well, if not, I'll vary rehydration water temperature.

TheAlchemist
07-02-2011, 07:25 PM
After following all this discussion on rehydrating, I'm wondering if anyone here has ever done a JAO side-by-side comparison of JAO as Joe directs vs JAO with <*gasp*> rehydrated Fleischmann's?

Chevette Girl
07-03-2011, 02:05 AM
On the to-do list... but my brew store doesn't carry go-ferm, I'll check out the other place in case they have it...

AToE
07-04-2011, 12:49 PM
On the to-do list... but my brew store doesn't carry go-ferm, I'll check out the other place in case they have it...

I haven't found one yet that does either, I just bite the bullet and order from morewinemaking.com whenever I need more supplies that are "exotic" like new yeasts, nutrients, enzymes, etc. Paying for shipping sucks, but I generally only have to do about 1 order at around 80-100 bucks worth of stuff every year, or year and a half, depending on how much I make.

Loadnabox
07-05-2011, 09:10 AM
I haven't found one yet that does either, I just bite the bullet and order from morewinemaking.com whenever I need more supplies that are "exotic" like new yeasts, nutrients, enzymes, etc. Paying for shipping sucks, but I generally only have to do about 1 order at around 80-100 bucks worth of stuff every year, or year and a half, depending on how much I make.

I had to order mine from midwest supplies, it's way cheaper to buy in bulk (at least 80g)

As for the results of rehydrating & giving it nutrients, I don't recall anyone reporting their results to this in particular, but it's generally assumed the wine would have a much higher ABV and be much Drier possibly requiring backsweetening.

AToE
07-05-2011, 02:17 PM
As for the results of rehydrating & giving it nutrients, I don't recall anyone reporting their results to this in particular, but it's generally assumed the wine would have a much higher ABV and be much Drier possibly requiring backsweetening.

This is true if one is making mead in the method of starting with a higher gravity and hoping the yeast stop where they're supposed to - but even then, at least it would be more consistant, with the dry pitch method as I understand it yes it's likely to ferment less, but unpredictably so most of the time.

But, for those who ferment dry and then stabilize and backsweeten, this changes nothing other than giving you a cleaner ferment.

And for those like myself who are fermenting to bone dry anyways, it's all good!

Loadnabox
07-05-2011, 02:24 PM
This is true if one is making mead in the method of starting with a higher gravity and hoping the yeast stop where they're supposed to - but even then, at least it would be more consistant, with the dry pitch method as I understand it yes it's likely to ferment less, but unpredictably so most of the time.

But, for those who ferment dry and then stabilize and backsweeten, this changes nothing other than giving you a cleaner ferment.

And for those like myself who are fermenting to bone dry anyways, it's all good!


True, but my answer was mostly in response to TheAlchemist's question regarding JAO which has a very high SG and is meant to finish sweet.

In this context my answer might make more sense :)

AToE
07-05-2011, 02:51 PM
True, but my answer was mostly in response to TheAlchemist's question regarding JAO which has a very high SG and is meant to finish sweet.

In this context my answer might make more sense :)

Ahah, yes then, carry on!

TheAlchemist
07-05-2011, 05:54 PM
Still not getting your replies...anybody out there "rehydrate" Fleischmann's before starting a batch of JAO?

Medsen Fey
07-05-2011, 06:33 PM
Yes, I've done it. It makes JAO that tastes just like JAO.

TheAlchemist
07-06-2011, 09:42 AM
Yes, I've done it. It makes JAO that tastes just like JAO.

Ha! That being the case, why bother?