Question on reusing yeast

[midnightmaraude]

Had a run of whiskey and left a bit of the wash to sit over the yeast bed in the bottom of my fermenter with the airlock in for probably a month. Before my new batch made this past wednesday I stirred up the fermenter and poured the remaining wash and yeast bed into a handle bottle (filled the whole thing) and stuck it in the fridge til I was ready.

So I made my new batch... had it at 105 degrees, warmed up the handle a bit and poured the whole handle into the new batch (overkill i'm sure). My question is...do you think the yeast were still viable? I always chicken out on reusing yeast and pitch 2 new packets each time anyway but I'm curious on what you all think.

[S-Cackalacky]

I don't know about the refrigeration part - maybe someone else can address that. Reusing the yeast is exactly what is going on when doing multiple generations of something like SF or UJSSM. I just recently finished four generations of SF over a period of about 3 months and only pitched yeast for the first batch. I've heard of others keeping some trub in a gallon jug and adding a little sugar now and then to maintain the yeast.

S-C

[red dirt shiner]

Might work might not but there's no harm in giving it a try.if you don't see any activity in 24 hours then pitch fresh yeast

[shadylane]

Just my $.02 worth.
It's hard on yeast to lay around in the bottom of a fermenter.
The pH is terrible and the left over wash is high in alcohol.
The yeast will mutate and learn bad habits.
On top of all these insults you then stuck it in the fridge.
Is the yeast still viable? I'd bet good money it is.
But it might not be what you want.

[pounsfos]

It's still good

I Stop reusing yeast after 6 generations, as I had one mutate on me on the 8th gen

next time you go to use it, water it down so it's not sitting in such high alcohol

I have stored yeast for 6 months in the fridge, and it worked fine.

There is a guide around here on how to wash and reuse yeast...

[Prairiepiss]

What are you making. I know you said whiskey. Bit that could mean anything around here. You never know what people will call what.

Have you ever read the UJSSM tried and true recipe? The whole thread?

[MitchyBourbon]

+1 shadylane

I would not reuse it. Sitting around a month in an environment that is not good for yeast. What was the abv of your previous wash? Alcohol over 8 % will damage yeast. It may fire right up but that doesn't mean that everything is perfect.

The best time to harvest yeast is before you even pitch it. Just make a starter, take a small sample before pitching and store it in the fridge. Pitch the rest. A couple days before your next ferment, start growing that sample. I can give details if any one is interested.

[GasLamp]

It's still good

I Stop reusing yeast after 6 generations, as I had one mutate on me on the 8th gen

next time you go to use it, water it down so it's not sitting in such high alcohol

I have stored yeast for 6 months in the fridge, and it worked fine.

There is a guide around here on how to wash and reuse yeast...

Anyway you could find a link to the guide? I've been searching a bit and haven't found it. I'm playing with some White Labs yeast right now (Bourbon Yeast, Scotch Yeast), and the White Labs statement is that yeast can be forward cultured up to 8 times before replacement. I'd like to try and reuse these strains (save money mostly), but have had poor luck in the past. My previous efforts consisted of taking a quart of mash prior to distillation, and inoculating a new mash with that. That failed, possibly for many reasons. Better directions on those efforts would help.

[GasLamp]

A few more thoughts based on my research:

Obviously the trick here is in carefully collecting viable yeast. It seems that yeast collected from high gravity mashes (over 1.06) do not work well, which seems like it would pose problems given many whiskey mashes approach that number. Also, the yeast are collected the from the yeast bed that collects on the bottom of the fermenter. If you are using a flat bottom bucket that makes sense, but how would try and collect yeast from a conical fermenter, where the outflow valve is on the bottom?

It almost seems to me the better way would be to take the initial yeast, make a larger starter, and subdivide that batch into aliquots (say expand to 1000mL, then make five 200mL aliquots). Put most of it in the fridge, use one aliquot, and then make a new starter from each aliquot when you want to ferment. Based on most reading I'd assume that each aliquot could be expanded about 6 times, so you'd get a lot of mileage this way. Having never tried this, thoughts?

[rad14701]

Bakers yeast is cheap which is why so many members here use it... No need to harvest and save... Not that you couldn't do multiple generations like the UJSSM recipe does...

As for the commercial yeasts, don't be fooled by labeling for Whiskey, Rum, Scotch, Vodka, etc... They are pretty much the exact same yeast with different labeling... Yeast is yeast and is only differentiated by the major strain... Saccharomyces cerevisiae, for example... Mutations aren't nearly as different as suppliers might like us to think...

Yeast isn't all that expensive in the grand scheme of things unless you get sucked in by hype... I'll stick with Fleischmann's Dry Active Yeast priced at ~$5.00 for 2 pounds...

[bellybuster]

I at one point had a yeast bank in the freezer of at least a couple dozen different yeasts.
I would purchase a package of liquid yeast and grow a starter. A small portion of that would go to the yeast bank (3 vials worth) and the rest of the starter would go to the brew.
These were more expensive yeasts bought for specific brews. The cost saving over the 10 or so years I kept this "bank" was quite a bit.
Here is one of the better tutorials on freezing yeast. It is easy to understand and thorough.
http://www.homebrewtalk.com/f13/guide-m ... ank-35891/

I would also often take some yeast from the bottom of a first ferment and toss it in the fridge for fairly long periods of time with no ill effect. Started right back up no problem.
Good labelling is key, otherwise it becomes mystery yeast. I always kept a few of those on hand too.....

[GasLamp]

That Bellybuster for the tips and the link. I learned pretty quickly in organic chemistry what happens when you don't label your beakers...

From the bank you derived from the starter, did you have the spin down or let the yeast settle to the bottom or did you just pour out a vial's worth and assume it had enough yeast floating around?

[bellybuster]

not sure I understand your question but... the frozen yeast samples would be the start of a new starter. The starter would be ramped up from about a cup of wort up to sometimes a full gallon starter in increments. There are many online calculators to ramp up yeast starters. each time I used a vial I would refill another from the first increment of the starter, this would be "gen2". My favourites quite often got thru 6 and 7 generations and I took one past a dozen before getting bored with it.
Made a cross country move a few years back and no longer have my bank. Once I get my brewery back in order I will for sure restart it. Great way to save some money. I easily saved a few hundred dollars in yeast purchases.

On that note, for distilling I like cheap bakers yeast. I also use bakers for meads, I have one slowly chugging away right now.

[MitchyBourbon]

+1 GasLamp,

A little extra prep to make a starter is the way to go, and less work than scooping it from a fermenter. If you have a stir plate the yeast will be continually aerated. If you keep the starter aerated the yeast will reproduce without producing any alcohol. I have kept 5 or 6 strains for a couple years now. I occasionally I re culture a strain from scratch to make sure it remains strong.

[warp1]

+1 shadylane

I would not reuse it. Sitting around a month in an environment that is not good for yeast. What was the abv of your previous wash? Alcohol over 8 % will damage yeast. It may fire right up but that doesn't mean that everything is perfect.

The best time to harvest yeast is before you even pitch it. Just make a starter, take a small sample before pitching and store it in the fridge. Pitch the rest. A couple days before your next ferment, start growing that sample. I can give details if any one is interested.

Mitchy...would love a simplified how-to on growing a yeast starter. I've been using US05 for my bourbon's at 6 packets for a 24 gal ferment. Would prefer to pull a little of the beer off, make a starter using a single packet or part of a single packet....seems way more economical and I have plenty of jars Have no clue how big a starter I'd need though....

Thanks

[SoMo]

I'm not Mitchy obviously but I've been pulling a pint jar worth of yeast and a few grain particles out of my fermenter storing in the fridge then adding to a new mash at the right temp and it takes off like a bat outa hell, it's as hard or easy as you make it, I do add a bit if fresh water to the jar first to reduce the alcohol saturation, and have never had a problem or a bad or off taste. Try it for yourself and see what it does for you, that's the only sure fire way to see how it works. Good luck.

[warp1]

I saw that SoMo in a prior thread and thought about it....but what Mitchy said made sense....why not just use fresh yeast versus an old culture? I figured if us05 is 3.50 a pop....but it would make 3 or more starter batches....pretty hard to complain.

I do run my gumballhead back on the existing yeast and sure I could grab some out of the fermenter. How much do you save for a new run...pint, quart, half gallon? I use a 55 gal fermenter filled with about 24 gal of liquid....couple half gallons should do it?

I agree on the keeping it easy part...both yours and Mitchys seem so....and it's great to know you're having good luck with it....I'll have confidence giving it a try.

[bellybuster]

Apple juice and a touch of nutrient makes great starters

[DAD300]

I've kept a quart of yeasty slop in the fridge for many months and it thrives. Think of it as a sourdough starter... It will have a layer of alcohol on top in a week or so. Now I drain off the alcohol and add some flour to feed the yeast ever week or so.

Last month I saved the slop from an all grain in zipper lock bags and put it in the freezer. If the yeast isn't alive it will still be good for nutrients.

[bellybuster]

.
Last month I saved the slop from an all grain in zipper lock bags and put it in the freezer. If the yeast isn't alive it will still be good for nutrients.

I tried something similar years ago and the yeast for sure died, but yes great nutrient. The longest surviving yeast in the freezer was about 3 days if I remember right. The notes from that are online here somewhere. Viability was tested on agar in Petrie dishes.
Properly prepared frozen samples can be kept for very long periods in the freezer

[MitchyBourbon]

+1 shadylane

I would not reuse it. Sitting around a month in an environment that is not good for yeast. What was the abv of your previous wash? Alcohol over 8 % will damage yeast. It may fire right up but that doesn't mean that everything is perfect.

The best time to harvest yeast is before you even pitch it. Just make a starter, take a small sample before pitching and store it in the fridge. Pitch the rest. A couple days before your next ferment, start growing that sample. I can give details if any one is interested.

Mitchy...would love a simplified how-to on growing a yeast starter. I've been using US05 for my bourbon's at 6 packets for a 24 gal ferment. Would prefer to pull a little of the beer off, make a starter using a single packet or part of a single packet....seems way more economical and I have plenty of jars Have no clue how big a starter I'd need though....

Thanks

Making a starter is easy, and if you have some equipment it doesn't take much of your time. If I am starting with a packet of dry yeast the first step is to rehydrate the yeast in plain luke warm water (95 - 100 F). This is important because dry yeast are like sponges, the cell membrane is not yet capable of filtering out impurities like sugar and other things you may have in your wash. Skipping this step can result in killing off half your yeast. To rehydrate, I put about 300 ml of wam water (previously boiled to sterilze) in a 1 lt erlenmeye flask and sprinkle the yeast letting it sit for 10 minutes to disolve on its own. Then I add another 300 ml lukw warm water and 2 table spoons DME and stir. Then I put the flask on my stir plate with a piece of tin foil loosely covering the flask. In 1 to 2 days it is ready to use in your next batch. (Optional) I move it to the fridge and let the yeast settle, then I decant as much clear water and pitch just the yeast slurry.

Some notes:
I do this optional step because the liquid usually does not tase like something I want in my bourbon. The reason I use DME is that I usually make my starters before I do a mash and DME is the closest thing to what my mash is. Using 2 table spoons DME in 600 ml should create a low gravity of around 1.035. The reason for such a low SG is that I am trying to make strong healthy yeast, not alcohol. I use a stirplate to keep the yeast continually aerated throughout the entire process. Because the yeast are aerated the whole time the yeast do not ever enter ananarobic state and therefore the DME is mostly used for its nutrients. Done right the yeast will produce more of themselves and very little alcohol.

Starters aren't just for all grain. They may be even more important for sugar heads. Most all sugar washes are for the purpose of making neutral spirits. Minimizing any esters, aldehydes, acetaldehydes, fusil oils etc. is desireable. Most of these congeners are created during the exponential growth phase of fermentation. Therefore if you create a good healthy starter with enough yeast to do the job you may skip or minimize the growth phase and the production of these congeners. Your neutral will be more neutral. I think Rob Zombie sings a song like that... More neutral than neutral.




A stir plate is not manditory, just put your starter in a one liter bottle covered loosely with tin foil. When ever you can (at least 3 times a day) put the bottle cap on and give it a good shake.

stir plate with water

[LG11]

Time is short so I will make this quick.
The conditions you described could actually be beneficial, there is no way I wouldnt try the yeast!!! Yes it will be viable, yes its likely that you have altered some of it genetically but that isnt always bad (how do you thin we make your commercial strains?), for the comment above about mutations after F8 Read one the pdfs attached, in a nutshell starve your yeast for saving it will fix it genetically and make it difficult (almost not possible) for other strains mutation to mate with it, would love to give detail but the paper below explains it all, I will answer questions if anyone dosnt understand whats in it.

response to heat and oxidation shock in yeast.pdf

(1.4 MiB) Downloaded 226 times

starvation method of genectically modifying yeast.pdf

(576.7 KiB) Downloaded 273 times

[warp1]

Thanks Mitch and LG....awesome