Lalvin 71b-1122 Racking Timing Question

I recently just racked a 5 gallon batch to secondary using 71b. my gravity was also 1.115 and it quite right at 1.010, which is perfect for me. Only difference is i used SNA with just fermaid O. Keep in mind this is my first batch, but i dont think i would ever want to take out of primary until fermentation is complete. I would either back sweeten at the end or add more honey in the beginnning so the yeast reaches its max before all the sugar is used up.

Hi JamesTIA - and welcome to this forum. My practice may not be the same as everyone else here but I tend to rack close to the end of active fermentation to help inhibit oxidation (the yeast is still producing a blanket of CO2) and to ensure that I don't rack off so many of the viable yeast cells so that the fermentation ceases as soon as it is in the secondary. That said, I would think that if you are of a mind to catch the bullet between your teeth (AKA stopping fermentation in mid-flight with billions of active yeast cells in the mead) - and I note that you did not refer to that act of real magic - I would think that it best to begin that process (multiple rackings while cold crashing close to freezing) when the mead is in the secondary and there is STILL enough residual sugar remaining to allow you to create a sweeter rather than a brut dry mead...

Well, there's back sweetening me then there's step feeding.

Back sweetening is waiting for the ferment to stop, cold crash and use chemicals (sulfite and sorbate) to stabilize and then add honey to the desired sweetness.

Step feeding is where you keep adding more honey until you've reached the alcohol limit of the yeast (usually + or - the stated limit by the manufacturer) and then adding a little more to get to your desired sweetness. It's approx. 1.5 lbs to raise your specific gravity by 0.10, so once it ferments down to 1.005 add enough honey bring it back up to 1.015, let it ferment some more, repeat until you've reached your desired sweetness level. It's more work and a longer ferment time.

I agree. Trying to interrupt the yeast during the course of fermentation deprives it of the ability to produce the full palate of flavours and aromas you want. And it's not easy to do, as anyone who's tried to stop a fermentation in its tracks can tell you. The best ways to achieve the amount of residual sweetness you desire are to:

A) Plan your fermentation with enough honey, over and above the yeast's alcohol tolerance level, to leave the excess as residual sugar in the amount you desire.
3oz of honey in 1 gallon of water will ferment to produce about 1% ABV. Multiplying this by the alcohol tolerance of your yeast (≈14% for 71B) and by the batch volume (in gallons) will give you the amount of honey required to ferment to a gravity of 1.000 at the yeast's target ABV. In your case, 3oz x 14 x 5 = 210oz = 13.125 pounds (or 13lbs, 2 oz) of honey.

Adding more honey will, of course, leave residual sugars. There is an excellent table in the GotMead NewBee Guide (Appendix 6 - ABV/Brix/S.G. Conversion Table) that allows you to calculate this additional amount based upon the desired finishing gravity. To do this, use the left-hand column (SG) and the right-hand column (P-ABV%). Let's use your batch as an example; you want a finishing gravity of 1.010 to 1.018 (a sweet mead). We'll average that to 1.015 for the purposes of discussion. The table shows that 1.015 finished gravity is the result of a 1.9% increase in ABV per gallon over the amount required to reach a gravity of 1.000 at 14%. We also know that it takes 3oz of honey per gallon to achieve a 1% increase in ABV per gallon. Therefore, the amount of additional honey to be added will be equal to (P-ABV% x 3oz x batch size) or (1.9 x 3 x 5) = 28.5oz or 1.78lbs (or 1 lb, 12.5 oz) of additional honey. So the total amount of honey for your batch should be about 14.9 lbs (14lbs, 14 oz).

It should be noted, here, that it is not unusual for yeasts to exceed their rated alcohol tolerance, given the modern methods we use. The addition of oxygen, staggered nutrient additions and the other measures we take to optimize the yeast's health and environment often result in performance that is higher than the ABV ratings established by the labs. Some honeys have slightly varying amounts of sugars, too. These can only be learned by experience, based upon the yeasts, honeys and regime you use. But these calculations should get you well within the ballpark.

B) Back-sweetening
Back-sweetening can be done very easily and predictably. No doubt, there are many ways to do it; here are the tricks that work for me:
1) Honey, in its natural state, is thick and does not easily dissolve in your must; it takes time and a good deal of stirring to arrive at a homogeneous solution each time you make an addition. And both the stirring and the time it takes allow exposure to the air and consequent potential oxydizing of your mead. I find it much easier to thin the honey I intend to add with 5 tsp of water per cup of honey. This results in a back-sweetening syrup that is easily miscible (dissolves quickly and easily) in the must and adds only a minuscule amount of water to the must.
2) I take a 1-pint sample of the mead and divide it into four 1/2-cup samples (#1, #2, #3 and #4) and add this syrup to them in 1/2 tsp increments (1/2 tsp to #1, 1 tsp to #2 and so on). Then I taste each to find the balance I consider best; of course each sample can be adjusted further, if necessary.

Each 1/2 tsp added equates to about 1/3 cup of honey per gallon of mead. That way I can adjust the sweetness to exactly what I tasted and liked best, without having to mix-and-stir, taste, mix-and-stir, taste, mix-and-stir, taste, etc.

I've learned to use this 'spectrum' approach, as I sometimes find that a level of sweetness (or dryness) I didn't anticipate results in unexpectedly good flavour. For example, though I like melomels on the dry side, I sometimes find that a little added sweetness can really make the fruit flavour stand out. And there have been some that I intended for complete dryness that actually turned out much better as sweets.

I also use the multiple samples to try other additions, such as acid blends or flavor adjuncts. Try adding a bit of almond extract to a peach mead and see what happens! Or a bit of cinnamon to a cherry mead. Mmmm!

C) Step-Feeding - As darogoni pointed out, step-feeding uses repeated additions, toward the end of fermentation to bring, or keep, the must's gravity where you want it to end up. I have not tried step-feeding, though I want to and will when the occasion arises.


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Eärendil
Miruvor Maker and Eternal NewBee
Mithlond Meadery, Grey Havens, Eriador

I would like to add a couple pieces as well.

I feel it's not a good idea to step feed the honey at the end of a fermentation when the yeast are not in their best shape. It's been a long while since they have had any food. The pH is low and the ABV is making harder to manage. This just doesn't seem like the time to add all this extra work on their plate. If you think you want to add more honey. Add that in one addition when you feel the growth phase is starting to transition into the stationary phase. This should be much more manageable to the yeast during this time. I find that most yeast tap out at such a high ABV that to add an amount over and above that point makes such a high abv, that it adds time to the ageing process in order to smooth out and become drinkable.

I would just completely forget trying to stop it in mid-stride.

I find that about 4-6 months after a mead is finished it seems as if the honey presence in the mead starts to step forward some. I call the first few months a "dumb period" where the mead hasn't had enough time to start to integrate the different fractions of the finished profile. So I would either wait for a while before you back sweeten. Or dial it in a little drier than you think might be your choice and wait for a while as the perception will usually get sweeter as time passes.

That sounds sensible to me, Squatchy; the end of fermentation is the point at which the yeast are dying and going dormant. Their population has shrunken commensurately and they would now have a higher level of sugar to contend with. This would seem argue for potential production of the off-flavors that yeasts can make when they're unhappy or overstressed, though I must admit that I have yet to actually try it.

I should think that it would be better by far to add the honey, either in the original must or at the height of the yeast's biomass size and fermentation ability which is, as you say, the latter part of the growth phase. Keeping the gravity a bit lower at pitch makes it a bit easier on the yeast; adding it later when they are at maximum population and ability gives them the greater load when they are most able to ferment it.

Like yours, most of my meads are palatable at the end of fermentation and improve over the next few months to a year. If you are not stabilizing, the few active cells left in your mead after racking will keep on working for awhile, until they go dormant too, which will dry the mead a bit more. Many of the finer aromas come out during this time, as well. It is a lovely experience just smelling and tasting them.


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Eärendil
Miruvor Maker and Eternal NewBee
Mithlond Meadery, Grey Havens, Eriador

So osmotic shock happens around 1107. As well all know it's common to start much higher than that. I usually start at 1120 out of habit. And then, as I mentioned above. I add one last addition of honey, to get to the same point I would have wanted, had I added it all up front. This way, I never really stress my yeast with a monster gravity. I have tried the other method a few times. And switched up to this method very shortly after the first couple times doing the step feeding. I won't go back.

JamesTIA - Since this is your first mead (or it sounded like that, anyway), you may not yet be aware of this; re-reading your recipe brought it to mind. It's about aeration.

We now know that most of the aeration methods used for mead musts up to now have been shown to be wholly inadequate. Ryan presented us with an excerpt from Chris White's book 'Yeast ... blah, blah, blah' (it's actually 'Yeast - The Practical Guide to Beer Fermentation', but 'blah, blah, blah' was how he laughingly presented it) on the GotMead Radio show of 9-12-2017. This excerpt reported the levels of dissolved oxygen resulting from various aeration methods. Levels were measured with a dissolved oxygen meter, so we're talking about direct measurement of dissolved O2, here. Those results were as follows:

Using 5.7 gallons of must/wort at 1.070 gravity
Shaking for 5 minutes – 2.7ppm
Splashing – 4ppm
Aquarium Pump or Lees stirring - 8ppm

The oxygen dissolved in the must is used by the yeast, especially in the lag and growth phases, to build strong, pliable cell membranes and synthesize sterols, which help the cell regulate transfers into and out of the cell. Anywhere from 12 to 15 ppm is the most desirable level for mead musts. Using Oxygen (O2) with a sintered aeration stone, you can reach 14ppm - 19ppm or more. The range of starting gravities for meads typically BEGINS at 1.100 and goes as high as 1.140; musts are much heavier in gravity than worts, have much more in the way of sugars, and thus require more dissolved oxygen to make proper amounts available to the yeast.

Nothing short of O2 and an aeration stone will get your yeast as much oxygen as they really want. It should be noted, here, that many fine meads have been made using shaking, stirring and aquarium pumps. But those fermentations are typically slower, more prone to problems and take longer to age to full integration than those with plentiful O2 additions. Just what you'd expect from yeasts that aren't entirely happy ...

It has been shown that, during the growth phase, yeast cells divide every 90 to 120 minutes; each cell division reduces the lipid content of the resulting yeast cells. With an adequate supply of oxygen, the cells can synthesize the sterols they require to properly transfer sugars into the cell for consumption and to transfer ethanol and CO2 out of the cell as waste, even in the face of this reduction of cell-wall lipids.

Without an adequate oxygen supply, however, they stop synthesizing these sterols. The cell membrane stops making these cellular transfers properly, causing acidification of the cell and consequent cell death, which can lead, in turn, to poor or stuck fermentations. Therefore, I administer oxygen every two hours or so, up to the 1/2 sugar break, in order to provide each generation of yeast with the oxygen required to allow them to produce the sterols they need. After the 1/2 sugar-break, exposure of your mead to oxygen (even atmospheric oxygen) should be avoided, as it will cause the yeast to generate sherry-like flavours, off-flavours and other undesirable characteristics to your mead.

I also administer graduated doses of nutrients at these aeration times but only up to the 1/3 sugar-break, when I cease all nutrient additions.

“Given sufficient nutrients, yeasts cells double in number every 100 min or so.”
("Life Cycle of the Budding Yeast Saccharomyces cerevisiae” by Ira Herskowitz, 1988)

"A typical yeast cell will divide every 90-120 min (depending on the exact conditions and temperature).”
("Growing Yeast (Robotically)” by Nir Friedman Lab, 2011)

“During the yeast growth phase, each multiplication cycle dilutes the lipid content of the yeast cell. When lipids become insufficient, the yeast cell membrane does not function properly under limiting oxygen conditions. Sterols, located around the membrane proteins responsible for the flux selectivity between the interior and the exterior of the cell, are no longer synthesized.” (“The State of the Art”, Lallemand, 2017 - underlining, mine)

“During fermentation, as the ethanol level increases, the yeast mortality increases. Without an adequate yeast sterol concentration, the yeast cell membrane permease activity suffers. .... This will lead rapidly to the acidification of the cell (drop of intracellular pH) resulting in cell death and stuck fermentation. So the more sterols are synthesized in the membrane, the better the resistance to ethanol is. (“The State of the Art”, Lallemand, 2017)

I hope this information is helpful to you.

Best Wishes to All!

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Eärendil
Miruvor Maker and Eternal NewBee
Mithlond Meadery, Gray Havens, Eriador