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.
Rehydrating Your Yeast
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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.
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?
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
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.
Of course one test would hardly be even remotely conclusive.
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
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.
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
You can get a nice bottle of still mineral water to rehydrate your yeast. The minerals help with rehydration.
Cheers,
Oskaar
Thanks! I have been using spring water, but I may give the mineral water a try.
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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". ;DSo 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'm a science type fellow, when I say "theory" I mean "fact"
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
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.
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.
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
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
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 and here 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
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!
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!
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.
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...
