sugar wash trials

[mogur]

Thanks, FruitsNNuts. Salt didn't seem to be a problem for the ferment when I used 10g/L Marmite. The main problem is the cost of it. Marmite is 3.6% salt, so I imagine that they must use a 1 or 2 percent salt solution, which becomes concentrated when they reduce it to a paste. Salt triggers autolysis by osmotic shock to kill the yeast and release the yeast’s own digestive enzymes which are responsible for breaking down the yeast protein. You could also kill the yeast with 42C or so heat, but anything above about 60C breaks down the endogenous enzymes and halts the process. Trub yeast is free, so try whatever method you think will work and see how the ferment goes.

Here is what I get when I hydrolyse ADY-

fresh out of the crock pot...

The supernatant becomes very clear amber when stored in the refrigerator.

[FruitsNNuts]

It seems that you can also induce plasmolysis (that' s a yeast only version of autolysis) of a cell by exposing it to a strong sucrose solution.
http://en.wikipedia.org/wiki/Plasmolysis" onclick="window.open(this.href);return false;" rel="nofollow

Hmmm….

So a recipes procedure might be:
Take 1/2 your traub from a previous batch and put it in a crockpot or other slow to heat cooker.
Add sugar, water, and an acid source. (I use ascorbic acid to clear out the chloramine anyway) and some tomato paste which is also acidic.
Sloooowly increase the temperature to boiling. (Low power, give it hours to heat up)
step 1 Starting point: with traub, sugar, water, tomato paste, vitamin C
step 2 Plasmolysize Yeast: (is that a word?) Sucrose causes yeast to tear itself up.
step 3 42c Kills the yeast and releasing all the B vitamines
step 4 After the yeast kill, taking the temperature up to boiling would fully invert the sugar. That would give our baby yeasts full access to the fructose and glucose.
Now add all that to cool water in the fermentor, mix in some air, and let it settle to 25c. That should make an improved yeast food to grow new happy, non stressed, good tasting yeast.

That's kinda elegant. No change in ingredients, just a modification of procedure.
Anyone see an obvious blunder here?
Otherwise I'm off to give it a shot. And thanks again everyone.

[mogur]

I believe your plan is excellent. Osmotic shock by a very high concentration of sugar should work great. Because fermentation at sugar concentrations of 20-30% is common, to really shock the yeast to autolyze, a much higher concentration of sugar would be required. I would recommend a saturated sugar solution. But that is doable because the autolyzate will be watered down in the wash. I would try to not get too carried away with the acid, though, since acid hydrolysis is usually done with very strong acids at high temperature, and neutralizing the hydrolyzate often produces a high salt concentration. Fermentation wants to in the 4-5 pH range, since the yeast itself maintains an internal pH of about 5.2, and in an acidic solution (less than 3 pH), the acidity can interfere with nutrient uptake. After my first run, I abandoned acid additions since I found that fermentation brings the pH down to 4 or less anyway. But I am no expert, so take my opinion with a grain of salt, grin.

[frozenthunderbolt]

Could try fresh pineapple or underripe kiwifruit as a cheaper alternative to papyin enzymes to hydrolyse with.
Used as meat tenderizer for too long they will turn the meat to paste.

[FruitsNNuts]

I would try to not get too carried away with the acid, though, since acid hydrolysis is usually done with very strong acids at high temperature, and neutralizing the hydrolyzate often produces a high salt concentration. Fermentation wants to in the 4-5 pH range, since the yeast itself maintains an internal pH of about 5.2, and in an acidic solution (less than 3 pH), the acidity can interfere with nutrient uptake.

That explains a problem I've seen. When I tried the original BW recipe, even though my water source is slightly base (PH 8.1) the ferments were really, really, slow. At the end of the ferment the PH was about 3.5 (WTF!) I looked closer at my tomato paste label and saw they had added citric acid. So I dropped the lemon juice and changed brands of TP (Now Contadina) and I now have a rather rigorous fermentation ending with a PH of about 4.5. I now use 2000mg of ascorbic acid to clear the chloramine, tomato paste, sugar, and boiled traub, that's it.
The starting PH is about 5 and everything is happy.

Thanks again for the input.

[mogur]

Could try fresh pineapple or underripe kiwifruit as a cheaper alternative to papyin enzymes to hydrolyse with.
Used as meat tenderizer for too long they will turn the meat to paste.

Yes, yes, yes. Papain is in the latex exuded from green papayas, collected by scoring the rind of living, green papayas. Pineapple enzyme is bromelain, from the stems of pineapples. It is almost as active as papain. Unripe kiwifruit I would have to research. But anything that breaks down meat (protein) is a good candidate. Amino acids are our friends. And broken down amino acids are yeast best friends.

[Buccaneer Bob]

Mogur, one of the things I am quite interested in is hydrolyzing gelatin.

I am just finishing up that rum ferment with the gelatin as a nutrient resource, and it did not nearly live up to my expectations.

When I first launched the ferment, it started off fast-and-furious, but then it trailed off pretty much like every other rum ferment that I have ever done.

The more I have been thinking about it, the more it makes sense to me.

I read in the Gelatin Manufacturers Institute of America's Gelatin Handbook that gelatin is made up of amino acids chained together in a wide variety of sizes by peptide bonds.

The hydrolytic conversion of collagen to gelatin yields molecules of varying mass: each is a fragment of the collagen chain from which it was cleaved. Therefore, gelatin is not a single chemical entity, but a mixture of fractions composed entirely of amino acids joined by peptide linkages to form polymers varying in molecular mass from 15,000 to 400,000.

So my yeasts were able to take up the lower molecular mass (smaller) peptide chains at the start of the ferment, and that gave them a short-term boost. But once the yeast had exhausted the "bite sized pieces", that was the end of the benefit of the gelatin addition.

So the Gelatin Handbook goes on to say:

Since it is derived from collagen, gelatin is properly classified as a derived protein. It gives typical protein reactions
and is hydrolyzed by most proteolytic enzymes to yield its peptide or amino acid components.

And they even give a table in the handbook detailing the concentrations of the various amino acids in gelatin.

So anyway, I'm thinking if we are going to hydrolyze the yeast anyway, why not add the gelatin at the same time and get a 2-for-1 special.

[Buccaneer Bob]

Of course, I don't know. The more I think about it, if I hydrolyze all of my yeast trub from every run and get the proteins broken down into "bite sized pieces", the hydrolyzed gelatin wouldn't even be necessary.

All the gelatin has to offer is amino acids (or nitrogen) at best. But the yeast offers us the exact amino acids we need for the new live yeast, but it also provides us with the B-vitamins, lipids, etc.

Yeah, I definitely need to hydrolyze my next batch of yeast trub and see where that gets me.

Mogur, have you come across anything regarding using papain, bromelain, actinidin, ficin, etc., on proteins at room temperature? I'm guessing the hydrolyzation process would take longer, but wouldn't the enzymes eventually get the job done at room temperature?

[mogur]

Mogur, have you come across anything regarding using papain, bromelain, actinidin, ficin, etc., on proteins at room temperature? I'm guessing the hydrolyzation process would take longer, but wouldn't the enzymes eventually get the job done at room temperature?

Of course published papers are going to deal with optimal autolyzation temperatures, so no, I haven't run across much about room temperature conditions.

The concentration of various nitrogenous compounds released during autolysis was studied by Freyssinet (1988). In the experiment, the autolysis was conducted at pH 3.0 and 40°C to expedite the process. The results showed that about 42% of the total nitrogen was released within the first 24 hours of the experiment; the remaining 58% was released during the following 14 days.

That's about as close to room temp that I have found, and I couldn't locate the Freyssinet paper online. My best guess is that a quick heating on the stovetop to 120F would kill the yeast and give the enzyme a head start on hydrolysis. Papain is most efficient at about 60C, but that temperature breaks down the yeast enzymes, so most studies aim for 50-55C. I certainly think it's possible that room temps would eventually work. You may be able to discern hydrolysation by the color of the supernatant. You can see the color of the supernatant in the photo on the previous page, while I believe if no hydrolysation happens it would be whitish in color. Here's a few links to yeast studies-

http://journals.tubitak.gov.tr/agricult ... 803-17.pdf
http://www.doiserbia.nb.rs/img/doi/0352 ... 05451V.pdf
http://www.extension.iastate.edu/wine/s ... lysis1.pdf
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3362713/
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1056959/
http://marmitelover.blogspot.co.uk/2011 ... rmite.html
http://nordicfoodlab.org/blog/2012/03/p ... extraction
http://technology.kku.ac.th/food-techno ... PF_081.pdf
http://www.aseanfood.info/Articles/11014014.pdf

[Buccaneer Bob]

Very cool. Thanks, mogur.

Yeah, I was thinking it might be good if people have options, you know.

If someone's in a hurry, they could heat up the mixture to an optimum temperature for a certain period of time and conduct their yeast hydrolysis that way.

And if someone's not in a hurry, they could conduct their hydrolysis at room temperature over a longer period of time.

What I am thinking is that I could have one batch of yeast hydrolyzing at room temperature while I have some other wash fermenting. When that wash is done fermenting, the next batch of yeast should be hydrolyzed and ready for the next fermentation. It's just a matter of maintaining a stack of one or more batches of hydrolyzed yeast so that one is always ready for the next ferment.

[mogur]

I like the hydrolysing gelatin idea. Will think about that, there's a lot of protein in those pork skins. Speaking of bacon.... nah

[mogur]

Okay, I screened out the gelatin, and collected the yeast. Washed it, and this is what I get (one gallon bottle). Trial five is in the tasting bottles, in the refrig, and I will get to it in a week. Did a taste test on trial four, no surprises, but will publish after this trial.

One more water wash, and this is what I use for washed trub yeast (minus the lees, and minus the supernatant.) I am assuming that the washed yeast is approximately 20% (w/v), so I use equivalent volumes of solution (milliliters) for trial data. May be off by an order of magnitude, but I do not have dry weight to pin this variable down to the gram. Just doing the best that I can. I suppose that I could evaporate 10ml of washed trub to find out what the exact w/v of washed trub, but come on, this is getting ridiculous. I am not trying for a phd in fermentation, just trying to find out what I am comfortable fermenting. No input from anyone on my next trial, so this will probably be my last-

wash trial six - setup.pdf

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[Buccaneer Bob]

Looking at that gallon jug of yeast trub has given me another idea.

You know how I was talking about conducting my yeast hydrolyzation at room temperature (slower, but eventually gets the job done) and having a stack of one or more batches of yeast hydrolyzing so that one batch of yeast is fully hydrolyzed and ready to go for the next fermentation?

And ... you know how a lot of us rum guys maintain a "dunder pit" for our rum fermentations?

Well, what about an "x-olyzing yeast pit"? (x-olysing being autolyzing and/or hydrolyzing)

1. Yeast trub is collected from each fermentation.
2. Trub is heated to 52 degrees C (?) to kill the live yeast but ideally leave its internal enzymes viable.
3. Trub is allowed to cool a bit (?) and then added to our "x-olyzing yeast pit" (a gallon jug, for instance)
4. Some papain-based meat tenderizer is added to the "x-olyzing yeast pit" periodically. Or alternatively, a little bit of the-fruit-of-the-day is pureed and added to the "x-olyzing yeast pit" whenever it's available. (fresh papaya, pineapple, kiwi, fig, etc.)
5. The "x-olyzing yeast pit" is shaken or stirred periodically, whenever it's convenient.
6. Before a new fermentation is initiated, the "x-olyzing yeast pit" is shaken or stirred once more to homogenize the mixture, a liter or so of x-olyzed yeast mixture is drawn from the jug, boiled to arrest the enzymes and kill anything else in the mixture, allowed to cool down below about 35 degrees C, and added to the new fermentation as a nutrient rich slurry for the new live yeast.

Part of me wants to say that the "x-olyzing yeast pit" could be stored in a warm part of the house and allowed to x-olyze at a medium pace, but there may be a problem with mold, bacteria, etc., formation.

I'm thinking that mold, bacteria, etc., formation would be problematic to the extent that it would lock up nutrients in the invading cells.

Boiling a draw of the x-olyzed yeast slurry prior to adding it to a fermentation would kill the invaders, of course, but a fair bit of nitrogen could be locked back up in longer-chain amino acids and unusable by the new live yeast.

So maybe it would be better if the "x-olyzing yeast pit" were kept in the refrigerator, which would slow down the x-olyzing process considerably, but it may be one way to ward-off formation of nutrient-robbing invaders.

Not really sure which way is best.

I just found this tidbit on papain:

Papain Concentrate has a temperature optimum range of 65 to 80C. The enzyme is extremely temperature stable in comparison to other proteases. Effective activity is demonstrated over the temperature range of 10 to 90C. Temperatures above 90C rapidly inactivate the enzyme.

So we have a whole range of temperature options for using papain.

I'm thinking storing someplace warm to start with, and then, if it looks like mold, bacteria, etc., is going to be a problem, moving the "x-olyzing yeast pit" to the refrigerator.

[mogur]

There are a lot of studies on room temperature autolysation of the yeast lees on wine and especially champagne. They are usually talking about a year or two. I don't know. I wish there was a way to measure autolysation in real time. As far as I know, we have to try it and test it. I know that most people won't incubate trub yeast at 52C for 24 hours. That is just silly. But, I am willing to play that game, because I am a geek, and in fact, I am planning to post a cheap ass instructible on a temp controller. Anyone that wants a cheap, ultimate yeast food will at least look at hydrolysation. But, I have also learned that tomato paste, even though it is at the bottom of the list for nitrogen content, is a really, really good nutrient that has consistently good taste. Bee pollen, flaxseed, kidney beans, soy flour, et al, are all good for ferment, but for cheap, good taste, trub and tomato seem to rule.

[DavidWatkins]

...but come on, this is getting ridiculous. I am not trying for a phd in fermentation...

Could've fooled me!

The essential criterion for a phd is that you increase the sum of humanity's knowledge in your chosen field beyond it's original boundaries.

Sounds to me, after reading this thread, that you've done that.

By the power vested in me by no one at all, I hereby dub thee, Doctor Mogur.

Lets have a round of applause for the man everybody!

[Buccaneer Bob]

There are a lot of studies on room temperature autolysation of the yeast lees on wine and especially champagne. They are usually talking about a year or two. I don't know. I wish there was a way to measure autolysation in real time. As far as I know, we have to try it and test it.

Wow, yeah, I was hoping more for a couple weeks, tops.

You know, I used to have a 100X-400X-1000X old-school, lab-grade microscope that I bought at a garage sale for $7. It was the real-deal, too, lighted stage, heavy enameled steel, real nice.

Before we moved to this Third World country where I'm living, I gave it to a buddy of mine who was going into nursing. Rascal doesn't even return my emails these days.

Given his track record, he's probably already dropped out of nursing school, and my old microscope is almost assuredly sitting on one of his shelves collecting dust.

If I had known then what I know now, especially how much I could use that microscope in my homebrewing projects, I would have definitely kept it.

I could be monitoring bacterial infections in my washes, seeing how active my yeast are, and with regard to yeast autolyzation/hydrolyzation, I could be looking at how completely the yeast cells have broken down.

Ah well.

I know that most people won't incubate trub yeast at 52C for 24 hours. That is just silly.

Not at all.

In light of what you said about the year-long deal, I'm already tossing around some ideas for heating.

...but come on, this is getting ridiculous. I am not trying for a phd in fermentation...

Could've fooled me!

The essential criterion for a phd is that you increase the sum of humanity's knowledge in your chosen field beyond it's original boundaries.

Sounds to me, after reading this thread, that you've done that.

By the power vested in me by no one at all, I hereby dub thee, Doctor Mogur.

Lets have a round of applause for the man everybody!

Totally.

[mogur]

Hey, thanks, guys. That is sincerely appreciated. Been on the controller project (http://homedistiller.org/forum/viewtopi ... =2&t=33439), and now I have incoming guests. Will get back to this thread soon.

[mogur]

Yesterday was hangover day, but back in the "lab" today.

Started on the washed trub yeast hydrolyzation. Harvested 660 ml of yeast. Fashioned a tinfoil petri dish so that my 100th gram scale wouldn't over load, and dried 10 ml of the yeast slurry in a 175F oven for two hours. Yield = 1.19 grams of residue. That means the slurry is about 12% dry yeast (w/v). At the same time, I also dried 10 ml of liquid meat tenderizer (the scientist from the distributor never called back with a concentration value, must be a proprietary concern). Yield = .38 grams of residue, or about 4% dry papain concentration (w/v).

650 ml of yeast slurry at 12% only gives me 78 grams of dry yeast to work with, so I modified trial six to accommodate that amount of 'trub'. Substituted an extra tomato paste and ADY bottle for one of the trub alone bottles. Now the entire trial six run requires 60 grams of hydrolyzed ADY, which I did last week, and 78 grams of hydrolyzed trub yeast, which will be ready late tomorrow.

As for papain, last week I used 20 ml to hydrolyze 60 grams of ADY in 300 ml of water. That translates to .8 grams of papain to 60 grams of ADY, or about a 1.3% papain concentration to yeast (w/w). I think we are in the ballpark with that concentration, so I will add 25 ml papain liquid to 78 grams of trub yeast today to be consistent with the earlier hydrolyzation.

Bob, that gallon of trub yeast eventually settled down to just three cups of slurry (I washed it once more after that picture), which means that I way over-estimated how much I had. Today's experiment indicating that the slurry is only 12%, puts the dry yeast yield at maybe 80-90 grams from a dry pitch weight of 9 grams, a fair portion of which may be some leftover dead yeast used for nutrition in the trial five bottles. That leads me to suspect that a 20 liter run would produce about 150 grams dry weight trub yeast, with the percent of living yeast unknown at this point. I do have a usb microscope somewhere around here. If I do find it, and it is powerful enough, just might get a rough idea of the live yeast ratio. Isn't there a stain that differentiates the dead cells from live? Will have to dig back into the studies to find out what that stain is.

[EDIT: didn't take long to find that trypan blue is the stain. A hemocytometer cell counting chamber costs $33 plus shipping, though, so maybe I will just leave that as an unknown for now.]

[Buccaneer Bob]

At the same time, I also dried 10 ml of liquid meat tenderizer (the scientist from the distributor never called back with a concentration value, must be a proprietary concern). Yield = .38 grams of residue, or about 4% dry papain concentration (w/v) ... As for papain, last week I used 20 ml to hydrolyze 60 grams of ADY in 300 ml of water. That translates to .8 grams of papain to 60 grams of ADY, or about a 1.3% papain concentration to yeast (w/w). I think we are in the ballpark with that concentration, so I will add 25 ml papain liquid to 78 grams of trub yeast today to be consistent with the earlier hydrolyzation.

Good to know. I had tried to find what concentration of papain would be necessary, but I couldn't find anything conclusive.

That leads me to suspect that a 20 liter run would produce about 150 grams dry weight trub yeast

That sounds real close to what I'm getting from my ferments. I haven't actually dried my trub. But usually I collect about a liter of sludge from every 20 liter ferment, and it settles down to about 1/3 liter of almost clay-like sediment. If I plug 1/3 liter into this yeast converter, it gives me 191 grams. But my settled yeast still has a fair amount of water in it. Once dried, it would probably be real close to 150 grams, I'm guessing.

[mogur]

Early data...

[mogur]

To translate the above graph, the first number is the bottle number, the number before each ingredient is g/L, and the lower case letter at the end is the inorganic nitrogen content: n = none, d = DAP only, and k = DAP and Fermaid K. I am flabbergasted by this trial. I thought the hands down fastest fermenter would be the 8ADY/8TRUBk bottle, since it has by far the greatest nitrogen content, but it is rather sluggish, so there must be some inhibitory effect going on there. Or??? The 12ADYn is the slowest, and the 12ADYk the fastest. Both the fast fermenters and the slow fermenters have wheat bran, tomato paste, DAP only, DAP/K, and no inorganic nitrogen among the bottles of both groups. This eliminates any possible easy generalizations for explaining what is a good nutrient to use. It seems the synergy between adjuncts is more complicated than I had hoped for.

Btw, I couldn't find my gelatin at the start of this trial, so bottle 8 didn't get its intended 2g/L gelatin and became identical to bottle 7, creating sort of a control test whether there is much variability between bottles with identical content. As you can see, bottle 8 got a little ahead of bottle 7 at first, but came back into line with bottle 7 later on.

Rigsby 1 sent me a very interesting message about encapsulating yeast and nutrients that I hope he will share with us. He mentioned the UK available Weetabix cereal gave him great results as a yeast nutrient, so I added it to the nutrient database.

nutrient data(1).pdf

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[Buccaneer Bob]

Yeah, there do seem to be some unusual early results, huh? The discrepancy between bottles 1 and 3 really jumps out at me. I am wondering if there may have been some other residual nutrients in the trub, perhaps?

That's just a theory on the discrepancy between bottles 1 and 3. But I am having a lot of trouble coming up with theories to account for some of the other seeming aberrations.

Can you think of any other factors that might be coming into play? Maybe different levels of oxygenation during mixing? Different amounts of light or heat?

[mogur]

Certainly overall, this run didn't suffer the lag time that trial five did. The only difference was that I turned up the thermostat to 70F, and a friend and I shook the bottles for two or three minutes each. I was a little lazy on run five and probably didn't oxygenate enough. I can't think of a variable between the bottles within each run, but there is a little more pattern to their fermenting curves later in this trial. I'll let them finish off and post the graph soon.

If we assume that the oxygen levels varied greatly between run five and six, then it seems like used yeast has an advantage over fresh yeast when the oxygen levels are low, and fresh yeast takes that advantage when the oxygen levels are high. That makes a little sense in that fresh yeast can build up reserves of facilitating factors (lipids, fortified cell walls, etc.) during a high oxygen growth phase, while the lack of oxygen gives an advantage to the used yeast that presumably already contains some of those facilitating factors from their prior growth cycle. In fact, the used yeast in this run came from yeast that grew in the oxygen starved environment of run five, leading to their poor performance in this trial relative to fresh yeast.

Of course, if I had research funding, I would find it fascinating to compare the performance of used yeast taken from fast, high oxygen ferments to the performance of used yeast taken from the slowest ferments. But, alas, I will probably just make sure to thoroughly oxygenate the hell out of any yeast that I have available, whether fresh or used, come up with a warmer ferment environment, and get to the still build.

[Rigsby 1]

My separate post on immobilizing yeast is here:-
http://homedistiller.org/forum/viewtopi ... =3&t=33536
I didn't want to draw this excellent thread "off-topic" but Mogur is happy that it is complimentary to his work.

Such immobilization of active ingredients is NOT my invention. It is used increasingly in industrial-scale fermenations/enzyme catalysis of many types, not just the making of ethanol. It does seem to be little-used, yet, on our smaller scales.

The attractions perhaps, for those interested in Mogur's thread, might be the convenience of the encapsulation of particulate matter, the big reduction in foaming I have observed, and the ease of monitoring SG on such clear liquids to assess fermentation progress.

[Dnderhead]

the best yeast is that is active,say from the top of active ferment.
the yeast that falls out last will be the most alcohol tolerant.
if you harvest yeast from bottom of ferment,it will fall out in layers,if you have a glass fermenter you will see this.
the top or last to fall is the best,this has fallen out do to lack of food and not because of "old age"
i have most stuff you need ,from stir plates , microscopes,and incubator.

[mogur]

the best yeast is that is active,say from the top of active ferment.
the yeast that falls out last will be the most alcohol tolerant.
if you harvest yeast from bottom of ferment,it will fall out in layers,if you have a glass fermenter you will see this.
the top or last to fall is the best,this has fallen out do to lack of food and not because of "old age"

Very interesting point, Dnderhead. So the equation gets really squirrely when healthy fresh yeast, healthy used yeast, bud-scarred old dead yeast, the effects of hydrolysation, the synergy between plant adjuncts, yeast, and inorganic nitrogen sources, as well as the effects of oxygenation (both current and during prior ferments of used yeast) are all taken into account. It's like herding cats, all of these variables has swamped any hope of being able to predict the outcome of a ferment with untried adjuncts. Tried and true recipes work. I have tried a few different recipes now, and have learned what works well for me.

i have most stuff you need ,from stir plates , microscopes,and incubator.

If that was an offer, thank you very much. But I must move on now, I am really getting tired of drinking bottom shelf vodka. I will just put on my magic jock strap, hydrolyse some yeast, and throw in a bit of grain or veggies, and then go solder some copper.

[mogur]

Here's what I have, make what you will of it. I promise that I didn't intentionally skew the data. I will try to figure it out, but this is just plain weird....

With the two identical bottles, there are basically 8 different trials in this run. Three went dry in about two days, four more in less than five days. One is still chugging along. Neither tomato paste, wheat bran, hydrolysed trub, hydrolysed ADY, absence of inorganic nitrogen, DAP only, nor DAP with Fermaid K came out the winner. Nor the loser. It's a real mixed bag of results. Too many variables this run, I guess.

wash trial six chart (final).pdf

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wash trial six (1).zip

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[mogur]

Okay, here's a real oddity. Most bottles had roughly the same mass loss at 48 hours.

But, the three fastest bottles stayed at that mass and were all fermented dry by the third day, while the slowest bottles all continued to lose mass for at least three more days until they fermented dry. Significantly more mass loss. Every study that I have read claims that the mass loss is directly proportional to the conversion of sugar to alcohol with the loss a direct measurement of the escaped CO2. Not true. The slowest bottles have some other process(es) besides fermentation going on. The difference is not explainable by evaporation, or else they would all continue to lose mass. I cannot find an explanation in the literature. Since I am not an expert in fermentation processes, I will just have to leave that as a mystery for now. Earlier runs (especially trial 4) also showed a similar pattern of the slowest ferments losing considerably more mass than the fastest, but I wrote that off to unmeasured foam loss. This run had no foam loss.

I wish I understood this run better, but the only conclusions that I can draw from it are as follows.

Bottle 9 was the slowest to ferment at seven days. It had 8 g/L hydrolysed ADY, 8 g/L hydrolysed washed trub yeast, and 210 ppm DAP plus Fermaid K. There seems to be an upper limit on the amount of yeast nutrients coupled with inorganic nitrogen. The only explanations I have are that either there is some excess amount of an inhibitory factor in this amount of nutrients, or that the excess nutrients provided an alternative pathway(s) that slowed the process of sugar conversion, such as yeast propagation, cell maintenance, or lipid production. Inhibition, however, doesn't explain the large excess of CO2 loss, so I would have to guess that some alternate pathway(s) may be responsible.

In attempting to compare tomato paste to wheat bran (bottles 4-8), I arbitrarily decided that 12 g/L of tomato paste was roughly equivalent to 8 g/L of wheat bran, due to the water content of tomato paste. The results of this run indicate that the two adjuncts performed almost identically (bottle 5 and 6 show this clearly).

Bottles 4 and 5 (as well as 1 and 3) indicate that hydrolysed trub is considerably better than hydrolysed fresh yeast. And bottles 5/6 versus 7/8 show that trub yeast performs better with DAP only, rather than with a nitrogen equivalent combination of DAP and Fermaid K.

Ah, and the winner is... bottle 2. 12 g/L fresh yeast with DAP and Fermaid K. Why? I can't even guess, but it roared across the finish line in less than two days. Now, in real wash terms (meaning 20 L washes), that is over a half pound of dry yeast, or about a cup and a half. Since the same amount of trub yeast (12 g/L) without any inorganic nitrogen finished in the middle of the pack, it is likely that trub yeast coupled with 212 ppm DAP would have outpaced bottle 2. But, again, that is a whole lot of yeast. It would take more trub yeast than an entire 20 liter wash would produce to supply the next 20 liter run at that concentration. On this run I had to substitute the planned 12 g/L TRUBd bottle with 8 g/L trub and 8 g/L ADY because I simply didn't have enough washed trub. And that bottle (9, the 8trub/8ADYk) surprised me by finishing last.

Well, thanks for taking this journey with me, and in spite of the fact that there are many more questions than answers, at least I think I have a basic grasp on fermentation now. I will finish off the tasting tests of these last two runs, and post an overall comparison in a week or two, and will include the taste tests as an important part of the ratings (along with cost, speed, and final ABV).

[Buccaneer Bob]

Awesome work, mogur.

Yeah, that is puzzling about the loss of mass. Something had to leave the bottles, but God only knows what.

[Rigsby 1]

Don't worry about it.
It's just the Angels taking their share.