Look up plating and slanting yeast. I only buy yeast when I need a new strain. Takes some planning, a week before brew day I take a scraping from the plate and start stepping it up. Don't have to worry about counting generations or store multiple quart jars in fridge.
Most people refer to it as washing yeast. There is a ton of information on different methods around this forum and it is really easy to do. Do some searches for yeast washing and check out the sticky that beergolf linked too and you'll be in good shape.
+10,000
I maintained a yeast bank on agar slants for ten years before I took an eleven-year hiatus from the hobby. I am currently in the process of rebuilding my bank. I currently have six different yeast cultures in my bank, and I am in the process of adding a seventh culture (see https://www.homebrewtalk.com/f163/plating-yeast-432004/). None of my cultures are available through the U.S. homebrew trade, which is the beauty of maintaining one's own yeast bank on agar slants.
If I were you, I would skip washing the yeast with boiled water. No professional brewer washes his/her yeast with boiled water. Washing yeast with boiled water does nothing but invite trouble, as boiled water is nowhere near as sanitary as beer.
All one needs to do is to leave enough liquid behind in one's primary fermentor to able to swirl the solids into suspension. As with the yeast washing process, one should wait a few minutes for the heaviest fractions of the trub and dead yeast cells to settle out after swirling before decanting the liquid into a well-cleaned and sanitized container. One should wipe the lip of the fermentor over which the "crop" will be poured with grain or 91% isopropyl alcohol before decanting the liquid (think about what a nurse or doctor does before he/she inserts a needle into one's arm).
Contrary to what most homebrewers have been led to believe, the culture needs some of the protein from the trub to remain healthy and beer is a much better environment for the culture than water, as the pH and the presence of alcohol deter bacteria growth. The widespread practice of washing yeast with boiled water in the homebrewing community can be traced back to Papazian's book. To the best of my knowledge, the practice appears in no professional brewing text. Professional brewers only wash their yeast when they want to kill off infection from house microflora. The solution that use to wash it lowers the pH to 2.2, which is signifcantly lower than that of tap water, which is at least 7.0 in most most municipalities (most municipalities buffer their water supplies to prevent corrosion of their pipes).
Rinsing, not washing.
Perhaps you could elaborate on why EVERY professional brewer who writes a book talks about yeast rinsing/washing??If I were you, I would skip washing the yeast with boiled water. No professional brewer washes his/her yeast with boiled water. Washing yeast with boiled water does nothing but invite trouble, as boiled water is nowhere near as sanitary as beer.
It definitely takes more than "a few" minutes. I think that 20 minutes is too short. Wolverinebrewer suggested 30. My brew partner is incredibly impatient, so we always went with around 25 minutes.All one needs to do is to leave enough liquid behind in one's primary fermentor to able to swirl the solids into suspension. As with the yeast washing process, one should wait a few minutes for the heaviest fractions of the trub and dead yeast cells to settle out after swirling....
Not bad. But, ideally... one should use an autosiphon instead of increasing the chances of transferring the trub, which you DON'T want.before decanting the liquid into a well-cleaned and sanitized container. One should wipe the lip of the fermentor over which the "crop" will be poured with grain or 91% isopropyl alcohol before decanting the liquid (think about what a nurse or doctor does before he/she inserts a needle into one's arm).
Perhaps you could explain this, then?Contrary to what most homebrewers have been led to believe, the culture needs some of the protein from the trub to remain healthy and beer is a much better environment for the culture than water, as the pH and the presence of alcohol deter bacteria growth. The widespread practice of washing yeast with boiled water in the homebrewing community can be traced back to Papazian's book. To the best of my knowledge, the practice appears in no professional brewing text. Professional brewers only wash their yeast when they want to kill off infection from house microflora. The solution that use to wash it lowers the pH to 2.2, which is signifcantly lower than that of tap water, which is at least 7.0 in most most municipalities (most municipalities buffer their water supplies to prevent corrosion of their pipes).
And if you use a sanitized autosiphon, as is done with every other racking step in the brewing process, what is the chance of taking bacteria along with your yeasty water??I have seen that decanting the slurry can reduce the non-yeast particles and does seem to take some bacteria with it.
I have seen no evidence to the contrary.But in the end wouldn't decanting beer and exchanging for boiled water increase long term viability and reduce bacteria levels?
How long after you begin refrigeration do you decant the liquid beer once the yeast slurry has compacted??I've ditched the traditional yeast rinsing approach, but I do decant the beer once the yeast slurry compacts in the jars.
No, really... MOST people refer to it as washing. Some people refer to washing as strictly acid washing.
Language is not created by one man.That may be how they refer to it, but that doesn't mean that's what they're doing.
Language is not created by one man.
Language means whatever the community wants it to mean. I see it referred to as washing over rinsing by a ratio of 4:1, so when someone mentions washing I know what they mean. If they say acid washing, I also know what they mean.
Context is key.
That's not an excuse to promote ignorance, especially in a group so generally receptive of learning.
And could you definitely elaborate on how you can reason that boiled water is nowhere near as sanitary as beer, which originally came from boiled water??
Beer has a lower pH than water. It also has alcohol. Both of these attributes make beer far less hospitable to bacteria growth than boiled water. While boiling can precipitate the buffering agent, one is left with a liquid with a pH of at least 7.0.
By "freshly opened bottle of distilled water", I assume you mean you DIDN'T boil the water??It had a big blob of mold or bacteria in it. It had been mixed from a powdered capsule and a freshly opened bottle of distilled water in a new specimen bottle and kept covered when a sample wasn't being poured into my pH meter cap.
I do think that EAZ has a point that any "yeast" that doesn't fall to the bottom within a day after being refrigerated in boiled water [with no oxygen], very likely isn't any yeast that you want to keep around, and is in fact, a "respiratory deficient mutant" (i.e. - "petities").I harvested some yeast a couple months ago and put it in a sanitized Mason jar. Very clean slurry. After it settled, I decanted it and poured boiled and cooled water on top of it. I had to off-gas the jar every 5 days or so, sometimes it had quite a bit of pressure built up in the jar, stored at ~38F.
Something was deteriorating (or growing)in that jar to produce the gas.
I did not. And neither did I boil it in the pH 4.0 solution. The 7.0 grew something, the 4.0 did not. Both had anti-mold drops added to them.By "freshly opened bottle of distilled water", I assume you mean you DIDN'T boil the water??
Did you read what I proposed? Water with pH lowered to pH 4.0.But for long term storage, boiled water trumps beer, and that's why it's recommended in every homebrewin book out there.
See post #16 of this thread...
Are you able to explain the yeast viability decreasing with more alcohol present over time.... much, much faster than boiled water present??
Minimizing the introduction of bacteria is of course going to accomplish the task of minimizing the introduction of bacteria. Absolutely no argument there.The alcohol is also keeping bacteria and mold at bay. Decreased viability is better than an infected culture. Yeast cells are going to lose viability no matter what one does under home brewery conditions. The name of the game is to keep the culture as clean as possible. Storing the culture under fermented beer versus boiled water accomplishes that task.
But my laser like focus is not on the contamination present in boiled water.By the way, your laser like focus on maintaining viability is causing you to ignore critical data that the author included in his blog posting:
"The top two sets of data, for 0% ABV and 4% ABV show very little drop in viability over time, but notice at about day ten there seems to be significant drop. This corresponds to the time I also started noticing mold cells growing with the yeast. Unfortunately, daily measurements created dozens of opportunity for contamination."
The data, outside of the graph, does NOT support your thesis. I really don't understand how the graph says what it says, when the table says what IT says. The wording of that sentence -- "The top two sets of data, for 0% ABV and 4% ABV show very little drop in viability over time, but notice at about day ten there seems to be significant drop." -- could perhaps be referring mostly to the 4% ABV reference numbers?? Only Woodland would be able to explain the disconnect between the graph and the table, IMHO.This data supports my thesis. It is more important to keep a culture clean than it is to maximize viable cell count at the cost of contamination. The opportunity for infection was present when all samples were taken. Yet, only the low alcohol samples became infected with mold. Low alcohol beer also tends to be less acidic beer because low alcohol beer tends to be lightly hopped. Hops lower the pH of beer, which, in turn, makes it tougher for unwanted microflora to gain a foothold. Brewers yeast strains have been domesticated to survive under the hostile conditions imposed by beer.
Im sorry,
That blog post may be a little misleading. My book is written better.
I agree with most of what EAZ is saying. There is no need to perform "homebrew yeast washing" which is better described as "yeast rincing.". I have seen that decanting the slurry can reduce the non-yeast particles and does seem to take some bacteria with it. "The Professional Brewer" mentions this technique very briefly and I could dig it up if you would like.
my experiments on alcohol effects on yeast do show degradation at high alcohol levels, but keep in mind these tests were done at ambient air temperatures. They show the effect of the alcohol on the yeast sitting at the bottom of a fermentor better than the effects in the refrigerator.
Yes, I think boiled water is better than beer for storing yeast, but don't want to discount all of what EAZ said. He has some good ideas.
Well, I'm not saying that an acidic medium isn't better than a non-boiled medium. What I'm saying is that a boiled medium is just as good as, if not better than, the acidic medium.... particularly in regards to long-term yeast viability.I did not. And neither did I boil it in the pH 4.0 solution. The 7.0 grew something, the 4.0 did not. Both had anti-mold drops added to them.
Enter your email address to join: