PDA

View Full Version : Yeast Nutrient When Racking?



evenstill
05-10-2007, 06:33 PM
As a general rule of thumb, should I be adding yeast nutrient
a. Only to the primary,
b. To both the primary and secondary, or
c. Every time I rack?

Also, does it matter if I'm adding more honey when I rack or not (whether I need to add more nutrient)?

Thanks,
evenstill

Chimerix
05-10-2007, 08:38 PM
The addition of nutrients and racking are pretty much unrelated.

For nutrients, the most commonly dispensed wisdom is to add nutrients at the start, after the lag, at the 1/3 sugar break, and possibly at the 2/3 sugar break.

I suppose that a racking could happen in there, perhaps transferring from a bucket to a carboy, but that process neither dictates, nor is dictated by, nutrient additions.

There are numerous discussions on nutrient addition schedules, or NAS, buried in here. Try searching for those terms, and limit the author to Oskaar. You'll still be reading for a while!

akueck
05-10-2007, 08:49 PM
Yup, what he said. In a nutshell: add nutrients when your yeast need nutrients. Rack when your yeast are ready (or rather, don't rack if your yeast aren't ready). Generally, your secondary is when fermentation is done. If fermentation is done, the yeast don't need nutrients.

You'll probably be admonished about adding honey when you rack (unless it's for backsweetening a stabilized mead). Adding honey periodically is called step-feeding. The end result is a very high alcohol mead, the last of which is fermented by some very stressed out yeast which are being pushed past their normal limits. Not always what you're looking for, so be aware. Happy yeast make happy mead. Sad yeast, well, don't.*

Love the yeast. Be the yeast. ;D

*an overgeneralization, I'm sure. Either way, when momma yeast ain't happy, ain't nobody happy.

evenstill
05-11-2007, 12:15 AM
“Generally, your secondary is when fermentation is done.”

Won’t the lees negatively impact my final product if I don’t rack the mead off after a couple of weeks? I always thought that you needed to rack to a secondary after about 1-2 weeks and let fermentation finish in the secondary, then rack a third time if it needs a bit of clearing. This is why I asked about adding nutrient to the secondary because that is where I thought the fermentation finishes. If this is the case would it be a good idea to add more nutrient. Do I not have to rack off he lees and if not how will it impact my final product?


“You'll probably be admonished about adding honey when you rack . . .”

Yeah. I don’t make a habit of it but I’ve got a batch where the yeast (Wyeast sweet mead) never took off so I had to pitch another yeast. I used Lalvin 1116 which has a higher alcohol tolerance so I figured I’d add just a bit more honey to the secondary to compensate. Is this ok or still not a good idea?

Luck,
evenstill

akueck
05-11-2007, 02:15 AM
From what I've seen and experienced, it's best to let things finish on their own in primary before you start messing with racking. You can rack after a week or two and let things finish in secondary, but you run the risk of stalling the ferment by doing so. Different yeasts will behave differently, and your experience will dicate how you run your fermentations.

But an extra week, or two, in primary won't generate many off-flavors from the lees contact. You're generally concerned with autolysis (dead yeast exploding themselves), which doesn't occur en masse for at least a month-ish, sometimes much longer (up to 6 months maybe). Good advice is to not rack based on the calendar. Every mead will come out a little differently, and every yeast will behave differently, so base your decisions more on SG and % of expected completion instead of "it's been 2 weeks". When you get close to your FG and activity is really slow (1-2 bubbles per minute in the airlock is a standard number), go ahead and rack to secondary. Lately I've been letting mine finish and drop lees before racking (usually between 2 and 6 weeks, depending on the yeast), since it's the lees you're moving the mead off anyway. (originally I was a calendar-racker, that caused some problems with underattenuation)

The issue with adding nutrients at racking is that they might not be needed. Too many extra nutrients in your mead can mean two things, both of which are bad: they can contribute odd flavors, and they can encourage spoilage organisms to grow by giving them food. One more reason to let things finish in the primary, then rack when it's done.

To your second point about adding extra honey...if you added it early enough it won't affect the yeast much. What you want to avoid is letting fermentation almost complete and then dumping more honey in. This will bump the alcohol way up but also stress out the yeast. Sounds like you're fine if you added it early in the process.

Oskaar
05-11-2007, 04:48 AM
Also be aware that there are Federal limits on certain levels of addiditves (eg the TTB limit on thiamin addition to wine or juice = 0.60 mg/L (0.005 lb/1000 gal). 27 CFR 24.246

So just be aware that there are federal limits on certain ingredients that may be present in your nutrients. This is just as there is a level of sulfites in wine, that requires labeling. That limit is 10 PPM (Parts Per Million) so virtually any wine or mead produced will contain that level of sulfites and should be labeled, especially if you are giving it to your friends who may be sensitive to sulfites. Otherwise you're playing Russian roulette with a possible reaction. A lot of people don't understand that sulfites are produced as part of alcholic fermentation. There are actually yeasts that produce as much as 225 PPM of sulfite during fermentation, so if you are making mead "naturally" using only fruits and juices for nutrients (instead of measurable amounts of nutrient), you are very likely producing well over the federal limit of 10 PPM of sulfites that requires labeling.

Cheers,

Oskaar

wayneb
05-11-2007, 10:36 AM
Yeah, Oskaar, this is something that has always fascinated me. BTW, I thought the federal law specifically stated that if sulfites are added in sufficient quantity to yield more than 10ppm, then the product had to be labeled. Naturally occurring sulfites were, like other naturally occurring substances, assumed to be part of the product. Anyway, my fascination comes from so many people who react almost violently to "sulfited" wines but seem to get along fine with "organic" beverages that contain no additional sulfites. I'm reasonably certain that most of the organic wines out there have at or above 10ppm naturally. Further, these folks seem to have no problem with most commercial grape juices, even though almost all white grape juices have KMETA added in sufficient quantity to retard the oxidation that causes browning.

Not that there aren't folks who are really allergic to sulfites, and for them drinking a sulfited beverage of any kind, natural or with added levels from KMETA, is a nasty experience. But I suspect that the number of people really sensitive is far fewer than those who claim to be.

UPDATE - OK, I did my homework and actually read the Federal regs. YOu are right, there must be a "contains sulfites" statement somewhere on one of the bottle labels if the measured sulfite level is at or above 10ppm. The key here is the term "measured." That's measured after bottling. I wonder how much residual bound sulfite (i.e. not released as free SO2 by reaction with the acids present in the wine) is typically present in bottled wine -- even those varieties produced with yeasts that are known sulfite generators. Do you have any insight into this?

Oskaar
05-13-2007, 02:28 AM
Hey Wayne,

Thanks for keeping me honest!! It's good to know that people are checking the things that I'm saying and not simply taking them on faith as that really helps one to know in their own mind that the information they're getting is good.

OK before I dive into sulfites in the bound and unbound form, a quick bit on sulfur and organic wine. I'm limiting this to wine because I don't know about the regs on food, etc. Be aware that elemental sulfur is used on grapes legally in just about all the "organic" vineyards. Also be aware that certain yeasts such as Pris de Mousse are able to metabolize sulfur and as a result will produce elevated levels of sulfur (above 50 PPM in the unbound state) as part of the fermentation.

Sulfur dioxide serves many functions in wine production. It is typically added in the range of 20 to 50 ppm. Higher levels are sometimes used in some areas to preserve juice for extended periods of time. SO2 is volatile, and will be lost from the wine over time due to volatilization. It is also reactive and will bind to phenolic and other components of juice, must and wine reducing the effective sulfite concentration. For this reason total and free (unbound) SO2 levels are monitored during wine production. (Bisson 2005)

Bound and unbound SO2
It is important to note that sulfur dioxide levels are affected by both pH and the fact that it is bound by many different substances in wine including tannins, thiamin, and certain oxidative enzymes such as polyphenol oxidase, Bisson (2005). Sulfur dioxide binds with other substances such as aldehydes and ketones Peynaud (1984), and will reduce over time due to chemical volatility. It is this affinity to bind and react with other substances in wine that necessitates close monitoring of the levels of free (unbound) sulfur dioxide before, during and after fermentation has been completed. Free sulfur dioxide is the form of sulfur dioxide desired for its antiseptic, preservative and anti-microbial effects in the wine during aging.

The inhibitory form of SO2 is thought to be the aqueous form of free SO2. The aqueous form is rapidly converted into ionized forms at wine pH. Depending upon the wine pH, SO2 may be completely ineffective at low doses as an antimicrobial agent. SO2 is detoxified by Saccharomyces. Saccharomyces is not inherently resistant to the inhibitory effects of SO2. Instead, it has developed mechanisms to eliminate this compound. This is accomplished by binding of the SO2 to yeast acetaldehyde produced during the fermentative catabolism of sugar. The acetaldehyde forms a complex with SO2 essentially inactivating its inhibitory potential. It is important to stress that this is a detoxification, because Saccharomyces is basically removing this compound from the environment, which is great news for other microbes present because it is no longer inhibitory to them as well Boulton et al (1996).

Multiple molecular forms of SO2 function as antioxidants and in the inhibition of PPO activity, so the pH effect on this function of sulfur dioxide is not as severe. In the case of SO2 addition as an antimicrobial, this will not be effective if Saccharomyces is or is about to rapidly catabolize the sugar. SO2 may play an important role as an antimicrobial post-fermentation, after the opportunity for detoxification has passed.

Also of note is the yeasts ability to metabolize sulfur and the production of sulfur dioxide during fermentation. Certain strains of Saccaromyces cerevisiae are known to produce large amounts of sulfur dioxide during fermentation that in some cases may result in levels of sulfur dioxide production as high as 225 mg/L, Delteil (ICV 1992). Different yeast strains are able to metabolize larger amounts of sulfur dioxide than others which in turn affect the total and free levels of sulfur dioxide present during and after fermentation. Long term storage and aging of wine will benefit from maintaining the proper level of sulfur dioxide in order to maintain color, freshness of flavor and fruity characters.

Sulfur dioxide is used for its antioxidant as well as for its antimicrobial activity. It impacts the microbial flora of the fermentation, but will also bleach color by reacting with anthocyanins. Since this binding is freely reversible, over time it will not permanently affect color.

Sulfite Sensitivity
Finally, chronic asthmatics are hypersensitive to SO2, principally because they lack an enzyme called sulfite oxidase. SO2 is a natural antioxidant produced in our bodies from the degradation of sulfur-containing amino acids. If an excessive amount of this natural antioxidant is produced, the enzyme sulfite oxidase will eliminate it via reaction with molecular oxygen. This is an important safety valve to assure optimal levels of SO2 are present without generation of too high of a level. Individuals who are deficient in sulfite oxidase have difficulty handling biologically produced as well as injested SO2. Failure to detoxify sulfur dioxide leads to symptoms similar to anaphylactic shock, commonly associated with an allergy. Thus low sulfite oxidase has been equated with an allergy to SO2. However it is not an allergic reaction in the classic sense, and is frequently fatal (this occurs in a very low percentage of the population, search the forums for the numbers posted in other threads). For this reason, winemakers willingly agreed to label their product as containing sulfites. Sulfite is also produced by Saccharomyces from the degradation of sulfur containing amino acids and during the course of reduction of sulfate for biosynthesis. For this reason, all wines are typically labeled as "contains sulfites" or the cleverer "contains no added sulfites" which means only biologically produced sulfite is present. In any case individuals with low sulfite oxidase activity should avoid wine and many other products Bisson (2005).

Dr. Andrew Waterhouse of UC Davis is working to fund a research project on sulfite allergy and sensitivity. A good rule of thumb is that if you know someone who is able to eat dried fruit that has been treated with SO2 without problems, but they are claming to be sensitive to sulfites in wine, they're probably not sulfite allergic or sensitive since the fruit will generally have a much higher content (at least 225 PPM sulfite) than most wines.

Hope that helps,

Oskaar

wayneb
05-13-2007, 01:24 PM
Hope that helps,



;D Your customary tagline -- especially appropriate this time. This is EXACTLY the kind of information and at the level of detail, that I was hoping for! Oskaar, I can't tell you how many times over the past few months since I discovered GotMead, that I wished I had the references and the training that you've accumulated over the years. But then in a way, we all do! You continue to be willing to share all this knowledge on an open forum, :angel10: and for that you have my unending thanks (as well as the promise that you'll have a few bottles of my best if/when we ever meet up in person!).

But you know, it would be handy to have access to all this information, extremely useful to the advanced meadmaker, "on the shelf" so to speak so we don't always have to keep pestering (or baiting) you with questions. ;) Have you ever considered writing an advanced technical book on meadmaking? References such as Ken Schramm's are very useful for the beginning to intermediate meadmaker, but I'd really like to have access to more data, in more detail, without having to take oenology courses (impractical for me here in Colorado) or sieving through technical papers on winemaking (also kind of hard to find around here). There are some good tech reference books on winemaking out there, but they are for obvious reasons focused on beverages made from grapes. We need something similar tailored to honey-based beverage production.

Probably only a niche market out there, but certainly no worse than any other scientific/technical textbooks. I'd buy one -- actually probably more than one, since there are a few people I'd offer them to as gifts.

Oskaar
05-13-2007, 01:33 PM
Dude,

You embarass me! LOL

I've talked to Vicky about some books that are geared toward specific types of meadmaking like, "Making Traditional Mead" or "Making Berry Melomels" or somesuch nonsense. The trick is taking the time to do it, and right now my time is at a premium. If I do a book or series of small books I want to be able to do it right, and I'm a freaking perfectionist so it's tough for me to let go of anything in the process.

I dunno. We'll have to see what transpires. I am going to start a series of Mead lab research projects that I'll post here on GotMead. Those may ultimately end up driving any kind of publication I end up doing. Who knows, I'm talking to a couple of different Laboratory facilities here in California that may end up funding some projects. Hopefully they will!

Cheers,

Oskaar

Leonora
05-15-2007, 04:25 PM
Hi,

Here are a couple of other place to look:

http://home.comcast.net/~mzapx1/
(Hightest's mead site. Page down to the middle of the page to see his FAQ and Tools section)

http://winemaking.jackkeller.net/index.asp
(a wine-making site but TONS of info)

Hope this helps as well.

Leonora

evenstill
05-16-2007, 01:06 PM
I am going to start a series of Mead lab research projects

Awesome . . . can't wait! What sort of things will you be studying? Are they going to involve stuff like nutritional content and possible health benefits? Will you be including the original mead (Hive Mead) in your research?

Luck,
evenstill

Dan McFeeley
05-16-2007, 03:42 PM
I am going to start a series of Mead lab research projects

Awesome . . . can't wait! What sort of things will you be studying? Are they going to involve stuff like nutritional content and possible health benefits? Will you be including the original mead (Hive Mead) in your research?

Luck,
evenstill

I would expect, from Oskaar, a series of experiments researching the alleged aphrodisiac qualities of mead, with Wrathwilde taking notes. Mark O. will also be present, lending moral support.

More seriously -- I hope this goes well. Research in meadmaking is badly needed. An era seemed to die with the passing of Roger Morse and Robert Kime. The home meadmakers have maintained the standard, but academia needs to hear about the potential in mead, and what the home meadmakers have been able to accomplish in meadmaking, and mead research.

Oskaar
05-16-2007, 08:35 PM
Hi Dan!

I'm hoping to get some scientific research funding going. Mead has been held in the dark for too long with many misconceptions about what it is and isn't. I want to subject mead to some cold, hard, unsympathetic scientific anlysis and see what it reveals. This is one of my main reasons for doing the UC Davis Wine Production classes. Just about any study that's been done is gone over in excruciating detail in their course curriculum, and associated texts.

The lab research projects we're doing there are performed on wine, however the analytical process may be used on mead as well. The ideas for studies that I'm getting as a result of the classes is pretty much what I'd hoped for. The biggest snag is finding someone with a gas chromatograph that's willing to burn some cycles for the purpose of mining a subject that really has not been approached scientifically since Morse and Kime as you mentioned. To me there are some very rudimentary things that can be performed by the layman such as myself that will hopefully spark some interest in the both the commerical scientific research and academia research communities. I think I have the entry channels analysed and targeted properly, so once my initial research gathering is done, I can put it out there in an effective format to generate some interest. At least that's the plan.

Hi Evenstill, unfortunately health benefits, whole hive and nutritional are not in my scope of projects. I'm looking at hardcore datapoint gathering and recording of fermentation kinetics, aging, must treatments, SO2, MLF, enzyme treatments and the like subjected to current technology and techniques for analysis and publication. This is the basic stuff that we don't have in the meadmaking community that we really should. Go to any enology or viticultural journal and you'll be able to gather more references than you can easily read in a week. But we don't have any such thing (with the exception of the aforementioned Morse and Kime studies) that is current, or within the last ten years that I know of. So that's where I'm aiming.

Initially it will just be me doing this stuff and recording my findings since there's no funding for research at this point. But hopefully we'll be able to leverage that into some practical studies down the road. Keep your fingers crossed.

Cheers,

Oskaar

wayneb
05-16-2007, 09:42 PM
Initially it will just be me doing this stuff and recording my findings since there's no funding for research at this point. But hopefully we'll be able to leverage that into some practical studies down the road. Keep your fingers crossed.


Oskaar, it doesn't have to be only you. I'd be interested in helping gather data for the research, as long as I don't need have a gas chromatograph in the basement to do it. Simple measurements like acid titrations and the like are things I'm sure several of us could do, and that would provide you with more statistically significant results. This could be interesting, an entire class of fermented beverages analyzed and characterized by a group of dedicated amateurs. Very much a "Renaissance Man" kind of scientific endeavour, and something that I could really get excited about.

Oskaar
05-16-2007, 10:21 PM
Hey Wayne,

You're right, there's no reason it should be just me doing this. The more grass roots analysis the better, and I didn't want to send the message that I'm the only one who should be doing this, or anything to that effect.

I think it's important that people do research and record their results accurately and timely in order to be able to draw accurate, unbiased conclusions about their research. But I think it's also important that people understand their experiment and what the parameters are before they start their little projects. Once the experiments are underway it is important that people record any and all data in order to present it in an unbiased way for analysis. That's what I'm after. There are many people who have preferences for making mead a certain way, and I aim to stay away from what my biases are and stick to simple and measurable studies. That's all.

BTW, be aware that acid titration is not a reliable method for measuring acid in mead. The honey actually undergoes a compensatory chemical process that has been researched and documented by none other than Mr Dan McFeeley. Do a forum search on acid titration with McFeeley as the author and you'll get plenty of insight into that. Some of the most daunting tasks involved with lab research is the up front analysis one must do in order to design valid test methodologies and procedures. Without solid background research and methods, the end results are suspect at best.

Cheers,

Oskaar

wayneb
05-16-2007, 11:53 PM
Oops! Acid titration was a poor example to throw out as an "oh, by the way" comment when we're specifically addressing mead testing, wasn't it? ::) Let me try again. What I was trying to do was to illustrate that many parameters can be measured without the aid of sophisticated and prohibitively priced equipment -- but of course although I have read Dan's postings about the uncertainties involved in titration of mead musts, that had completely slipped my mind when I typed my earlier post.

Anyway, I think that in order to proceed forward with more than a single individual taking measurements of any kind, a set of measurement protocols needs to be agreed on, and then every prospective experimenter on the team needs to be "calibrated" by performing the test protocols on known standards. That way, the quality of their measurements can be assessed against those known standards and also they can all get some valuable practice in specific measurement technique. Then those protocols, or variations thereof, can be employed by the ensenble of individual experimenters to collect data from a wider variety of samples than can be expected from only one experimenter. Additionally, if there are any systematic errors being introduced by an individual by way of the manner that they perform a procedure, those errors can be mitigated by having results from several different individuals averaged into the ensemble results.

Finally, Dan, I'll never let your titration results slip my mind again - I promise! ;D

Oskaar
05-17-2007, 06:48 AM
Oops! Acid titration was a poor example to throw out as an "oh, by the way" comment when we're specifically addressing mead testing, wasn't it? ::)snip


No biggie dude! LOL



Anyway, I think that in order to proceed forward with more than a single individual taking measurements of any kind, a set of measurement protocols needs to be agreed on, and then every prospective experimenter on the team needs to be "calibrated" by performing the test protocols on known standards. That way, the quality of their measurements can be assessed against those known standards and also they can all get some valuable practice in specific measurement technique. Then those protocols, or variations thereof, can be employed by the ensenble of individual experimenters to collect data from a wider variety of samples than can be expected from only one experimenter. Additionally, if there are any systematic errors being introduced by an individual by way of the manner that they perform a procedure, those errors can be mitigated by having results from several different individuals averaged into the ensemble results.

Finally, Dan, I'll never let your titration results slip my mind again - I promise! ;D


I agree with you on having everyone singing from the same hymnal and doing things the same way. I'm going to be concentrating on certain things that I want to do in a certain way using certain methods, and being me, I'm not willing to change those methods until I have a comfort level with my results over several runs. If you want to take this conversation to PM I think I can give you a good idea of what I'm planning.

Thanks,

Oskaar

Dan McFeeley
05-17-2007, 02:29 PM
BTW, be aware that acid titration is not a reliable method for measuring acid in mead. The honey actually undergoes a compensatory chemical process that has been researched and documented by none other than Dan McFeeley. Do a forum search on acid titration with McFeeley as the author and you'll get plenty of insight into that.

You could also post to these forums, or send me a PM, since I hang out here. ;D

But of course, do a forum search first. ;D ;D ;D

I've done some other stuff with acidic properties of honey and mead, and how that affects flavor profile. It's all summed up in a Zymurgy article (Sept/Oct 2006), penned by myself.

I've felt for a long time, years actually, that mead is a completely different beverage as compared to wine. Mead isn't a "honey wine," mead is mead. What I found in the relationships of gluconic acid, glucose sweetness, and the unique flavor contributions of the varietal honey/s is a support structure (borrowing from Peynaud) completely different from that of wine.