According to John Palmer one can harvest yeast from the primary and store it in a sanitized jar in the refrigerator for up to a couple of months. The yeast will turn brown as it ages. Once it turns the color of peanut butter it must be discarded because eventually the yeast will autolyze and die as its nutritional reserves are used up.
What are your thoughts on this? Has anyone witnessed this effect?
I have witnessed this effect of browning after a couple of months. I have also had good results with six month old harvested yeast. I made a Marzen with a six month old yeast.
I made a starter from the six month old harvested yeast in accordance with Mr Malty using 25% viability. The starter was fermented and cold crashed then the spent wort was decanted and the slurry pitched into a 1.052 Octoberfest at 48F. The beer finished at 1.015 and was excellent. Clean and malty with a nice hop bitterness and flavor.
I don’t know - I’m just tagging this thread to see what the schmart folks say.
I’ve had harvested yeast for at least six months, but whiles its gotten darker, I would never describe it as peanut butter. I don’t wash my yeast, maybe that has an impact…
I recently grew up from a 17-month old slurry of 2206. The starters and the main batch behaved like I would expect. I think if you’re conservative about your viability estimates (and have good sanitation, obviously) you can keep yeast in the fridge indefinitely. The viable cell count will get very low after a while, but I don’t know of any reason that would affect the performance of the yeast that do survive.
Maybe Palmer meant that six months was the maximum for direct pitching? If so I wouldn’t even go that long.
"If you harvest yeast from the primary fermentor, you will need to separate the yeast from all the trub that is mixed in. Professional brewers most often do this by “acid washing” the yeast–using acid to lower the pH to about 2.5 so that bacteria is inhibited and using whirlpool methods to seperate the heavier trub from the lighter yeast. But acid washing tends to inhibit the yeast too, and is not strictly necessary. You can simply use chilled boiled* water and two sanitized jars to separate the healthy yeast (white) away from the majority of the trub.
After racking the beer, swirl up the yeast layer on the bottom and pour some into a large sanitized jar (such as a mayonnaise jar).
Gently pour in some cold, boiled water and swirl it up to get all the yeast and trub in suspension.
Let the jar sit for a minute or three to allow most of the trub to settle to the bottom. Gently pour the cloudy water, containing suspended yeast, into another sanitized jar. Discard the dark trub.
Add some more water and repeat this procedure until you are left with a substantially light-colored yeast suspension and only a thin brown layer of dead yeast and trub on the bottom of the jar.
Store the jar in the refridgerator for up to a couple months. The yeast will turn brown as it ages. Discard it once it turns the color of peanut butter. Eventually the yeast will autolyze and die as its nutritional reserves are used up.
Pitch the yeast to a starter before using to ensure its vitality. If the starter smells wrong–rancid, vinegary, etc., the yeast may be contaminated. The dominant smell of a starter should be a yeasty smell, but sulfur smells are not necessarily bad, especially with lager yeast strains."
And here, sort of… but my experience is with slurries just a bit shy of 6 months.
I’ve rarely ever waited that long to brew, even in busiest of times, but then again I’m not one for switching yeast strains all that much either… I’ve never had more than two (or three at most) different strains of slurry in the fridge. I don’t wash the yeast, and longest I’ve ever kept one and reused it was probably at about 4 months old. I fed it up a bit two days before brewing and it worked fine and fast…and the finished beer was clean and good. I think I’ve had good results because I am particular about sanitation, and I store the slurry very cold.
The last batch I did I poured about a gallon of cooled boiled water into the primary after I racked the beer and swirled it around. Then I filled up a pint jar and put that right in the fridge. The rest of it I poured into a big plastic pretzel container and let it settle overnight. The I decanted the liquid into a 1 gallon jug and put it in the fridge, decanted again after 24 hours and poured the slurry into a small jar.
So what I’ve got is an ugly looking slurry jar and a small jar with a thin layer of very clean looking yeast at the bottom of it.
I just saved some slurry from a batch that I left in the carboy for 5 weeks. After siphoning the beer off I swirled and poured the slurry into two pint jars and 3 smaller vials which were half full of steril water. After sitting in the fridge for half a day I looked at them, they all have 1/3 water on top, 1/3 yeast which is darker looking like peanut butter and 1/3 creamy white yeast at the bottom. I’m not sure how I could separate it any further without losing the good yeast at the bottom?
I’ve never washed harvested yeast. I do the same as you Dean. I generally use about 2-3 Tbl of the harvested yeast to make a starter. I don’t know what effect washing the yeast will have on the beer. Might have to try someday.
CONCLUSION from this thread (and similar)-U do NOT (nor does anyone else) know how long YOUR yeast can be stored or the next one U save will live just as U do NOT know how fast U can drive on Dead man’s curve on a rainy night-YMMV!!-save it until u need it and make a starter.
I think you can say that with a lot of the accepted norms, especially when brewing beer. Look how opinion has changed with nearly every aspect of brewing already. Everybody has an opinion and you know the rest of that saying… ;) ;D
I too keep yeast in sanitized jars for months and months without washing. Haven’t had a problem making a starter with 6 month old slurry. Even pitched a jar of one month slurry without a starter and it made a great beer.
Go to www.mrmalty.com and select the pitching rate calculator, then select your settings for qts/gal or liters etc, the type of beer you’re going to make, original gravity, batch size and at the bottom select “slurry”. I’m not sure what you’d put for a date on the slurry but as you move your mouse over some of the selections it gives you information to help you.
Double CHEERS to JZ & JP then because I am living w/BREWING CLASSIC STYLES also. And Cheers to all that have more knowledge than me and are willing to share (Wow, thats a lot of beer!).
