When is the wash completely fermented

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Andrew_90
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When is the wash completely fermented

Post by Andrew_90 »

So I have read that when you reach .990 this a measure of "doneness" of the wash.

My Shady's Sugar Shine wash is located in my garage and the lighting is poor, tonight the Hydrometer measured 0.992. Out of curiosity I shone a torch into the wash vessel and noticed that there are still lots of fine bubbles percolating up to the surface, so the fermentation process cannot be complete.

I was about to add some Bentonite to settle out the wash but am concerned that the bubbles percolating up will counteract the settling effect of the Bentonite.

What is the conventional wisdom for wash "doneness", other than the hydrometer that is? Absolutely no bubbles? Or are those fine bubbles diminishing returns i.e. the fermentation process is for all intents and purposes over.
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zed255
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Re: When is the wash completely fermented

Post by zed255 »

When the hydrometer reading is absolutely stable for multiple readings over multiple days and the ferment has a dry or sour taste, no sweetness. The actual reading is not too important and depends on various factors but should get into the right 'ballpark' so to speak for a given fermentation.

A ferment can continue to bubble for a while just releasing built up CO2 after fermentation has completed, so bubbles are not a reliable indicator.
Last edited by zed255 on Tue Sep 22, 2020 1:28 pm, edited 1 time in total.
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Demy
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Re: When is the wash completely fermented

Post by Demy »

Hello, this depends on what you are fermenting, it does not necessarily mean that you have to go below 1000, for example some types of fruit stop at 1006 or higher, even yeast can contribute to a certain extent. To understand when the fermentation is finished, evaluate a few things: no bubbles, the hydrometer will give you the same measurement after a few days, any solid sediments usually go down to the bottom. If you are in a hurry you can distill when you see only a few sporadic bubbles but not when there is an evident sparkle. This is my experience.
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Saltbush Bill
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Re: When is the wash completely fermented

Post by Saltbush Bill »

fine bubbles fizzing on top indicate the ferment is still going, stick a finger in and taste it....my bet is you will still taste sweetness at this stage. When its tart / dry tasting its done. Why the Bentonite? SSS clears beautifully on its own given a day or two.
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kiwi Bruce
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Re: When is the wash completely fermented

Post by kiwi Bruce »

I don't think anyone has mentioned this...in distilling you don't want a wash to go to zero, the reason is...we ferment our washes with a huge excess of yeast. 10x what you would start off with for beer, and 100X for wine...we don't want our little friends sitting around and letting other organisms take over and ruin the flavor of our distillate ( wine is protected by tannins, beer by hop oils :- but our washes have nothing to protect them except speed) So as the sugar level starts to drop, this massive excess of yeast has nothing left to feed on and starts to die off...and then break-down :- autolysis and the off flavors can, again, ruin our distillate. So stop your ferment early and run it ASAP.
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Re: When is the wash completely fermented

Post by seabass »

Not sure what you're doing, but I use typical beer pitching rates for my yeast. I've never gotten even a hint of autolysys happening. Autolysis won't happen during active fermentation. It would have to sit for a very long time for that to happen. There isn't a reason to stop the fermentation before it's done. If you don't want other microorganisms taking hold, you'll want to add a boil and chill before fermentation and have typical beer brewing sanitation practices. Otherwise, you're gonna get a little bit of lacto unless there's some kind of pasteurization happening before fermentation. A high mash temp and quick chill should be enough to stave off lacto during fermentation.


Edit: didn't realize this was in the sugar section. NVM. Different rules for sugar.
Andrew_90
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Re: When is the wash completely fermented

Post by Andrew_90 »

Saltbush Bill wrote: Tue Sep 22, 2020 1:29 pm fine bubbles fizzing on top indicate the ferment is still going, stick a finger in and taste it....my bet is you will still taste sweetness at this stage. When its tart / dry tasting its done. Why the Bentonite? SSS clears beautifully on its own given a day or two.
My kids are flying my wife and I to Cape Town on Friday for my 60th. I wanted to do a stripping run before I left, so wanted tp make 100% sure that she had settled, I note that patience is a virtue in distilling and I am patient, future washes will be left to their own devices visa vie settling.
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Saltbush Bill
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Re: When is the wash completely fermented

Post by Saltbush Bill »

It wont hurt to leave the wash for a week or two as long as its under an airlock.
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Demy
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Re: When is the wash completely fermented

Post by Demy »

kiwi Bruce wrote: Tue Sep 22, 2020 3:53 pm I don't think anyone has mentioned this...in distilling you don't want a wash to go to zero, the reason is...we ferment our washes with a huge excess of yeast. 10x what you would start off with for beer, and 100X for wine...we don't want our little friends sitting around and letting other organisms take over and ruin the flavor of our distillate ( wine is protected by tannins, beer by hop oils :- but our washes have nothing to protect them except speed) So as the sugar level starts to drop, this massive excess of yeast has nothing left to feed on and starts to die off...and then break-down :- autolysis and the off flavors can, again, ruin our distillate. So stop your ferment early and run it ASAP.
This could happen but from all my yeast readings it seems that the autolysis process is a problem if we leave the ferment for a long time and under high pressures (e.g. very high conical fermenters). I don't think a couple of days makes a difference. I know you have a lot more experience than me, so I might as well blunder.
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Saltbush Bill
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Re: When is the wash completely fermented

Post by Saltbush Bill »

Ive never known it to be an issue......might be more relevant to AG mashes than to sugar washes.
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kiwi Bruce
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Re: When is the wash completely fermented

Post by kiwi Bruce »

I deliberately over pitch, a cup and a half of rehyrated Red Star bakers yeast in seven gallons...and I end it when it's slows to one bubble every 10 seconds...this is under ideal circumstances...have I left it longer ? of course I have, I'm a lazy old fart...and has it affected the out-come of the last drop? That's debatable !
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