Reusing dried yeast

[rpt]

I've started collecting trub when I bottle and rinsing the yeast to repitch. I've so far done this with dried yeast (Nottingham and S04) with great success. But recently I've read in two places you shouldn't do it with dried yeast. Doesn't anyone know if this is true and why?

 

[zgoda]

I don't know, I'm doing this all the time.

 

[johnnyboy1965]

Ive also read this...don't know why...the only thing I can think of is it financially viable...Price of wort, electricity, time etc

 

[LeithR]

Like zgoda I recycle dried yeast all the time without any probs - so far I've only used Nottingham and SO-4 but have a whole bunch of other yeasts to try. Go for it.

 

[rpt]

Ive also read this...don't know why...the only thing I can think of is it financially viable...Price of wort, electricity, time etc

Reusing dried yeast is free. If you repitch soon enough you don't need a starter. So the only cost is some cooled boiler water. Perhaps some people don't think it's worth it as dried yeast is cheaper than liquid, but it's still a good way to save money.

 

[iceo]

iv done it with dried wine, cider and ale yeast, got 3 different lots in my fridge at the mo

 

[jonnymorris]

You shouldn't make a starter with dried yeast but re-using is fine in my experience.

 

[rpt]

You shouldn't make a starter with dried yeast but re-using is fine in my experience.

But when you reuse it, it isn't dry any more so you will need a starter if you have insufficient cells.

 

[jonnymorris]

But when you reuse it, it isn't dry any more so you will need a starter if you have insufficient cells.

That's what I meant. Was just trying to think of what not to do with dried yeast but yes, when it's wet, it's not dry. :wha:

 

[saccharomyces]

I do not know when rinsing yeast with boiled and chilled water became the rage (it clearly occurred while I was on hiatus from the hobby), but it is a completely unnecessary step that does more harm than good. Boiled water isn't absolutely sterile. Microflora spores can and do survive 100C moist heat. To kill spores, one must autoclave (pressure cook at 121C @ 15 PSI) water for at least fifteen minutes. Additionally, the pH of water is much higher than that of beer, which allows pH-sensitive spores to germinate. A yeast culture takes over a batch of wort by consuming all of the dissolved oxygen, lowering the pH, and producing alcohol when it shifts from respiration to fermentation. Adding oxygen, raising the pH, or removing the alcohol removes the pitching yeast's protective barrier.

Many amateur brewers confuse yeast rinsing with proper yeast washing. Proper yeast washing is performed with an acidified solution. The purpose of proper yeast washing is to drive the pH of an infected culture down low enough kill off (or at least seriously weaken) everything but the pitching yeast. The pitching yeast is also weakened during the process; therefore, yeast washing is often little more than a band-aid. One usually has to go back and propagate new pitching yeast from a slant or a plate using aseptic transfer technique to perform the first inoculation.

All one has to do to crop yeast from the bottom of a fermentation vessel is to scoop the yeast out with a sanitized spoon and store it in a covered sanitized jar. If one uses a carboy as a primary fermentation vessel like we do in the United States, one can crop yeast by leaving just enough liquid behind while racking to be able swirl the sediment into solution, waiting a couple of minutes, and decanting the liquid fraction into a sanitized jar after wiping the mouth of the carboy with an ethanol soaked cotton ball. In both cases, it is better to leave the yeast under green beer than it is to leave it under boiled water. As mentioned above, the pH of green beer is significantly lower than that of boiled tap water, especially alkaline tap water.

On brew day, the stale beer should be replaced with fresh wort from the batch that one just brewed before the contents of the jar are swirled into suspension. One should wait a couple of minutes for the heaviest fraction to settle before pitching the liquid fraction into one's new batch of wort. If performed properly, most of the trub, hop particles, and dead yeast cells will be left in the jar after the liquid fraction has been decanted.

 

[saccharomyces]

But when you reuse it, it isn't dry any more so you will need a starter if you have insufficient cells.

There is usually more than enough yeast left in a fermentation vessel to ensure a healthy fermentation without having to make a starter. In fact, there is usually several times more yeast available than is needed to pitch one's next batch.

 

[chrig]

Controversial post is... Controversial!

washing, or you say rinsing, yeast before pitching or even freezing has become quite common practice on this forum. Its interesting to hear another experienced view point.

 

[pittsy]

I don't really like using the slurry , all the dead yeast and **** . Better to use the fit healthy yeast from top cropping or if you forget or miss out , i make a tiny starter from a bottled batch (not too old ) it tends to be the fitter yeast imo .

 

[jonnymorris]

I do not know when rinsing yeast with boiled and chilled water...

Great contribution, thanks. I don't wash or rinse but try to seperate out the **** from the reclaimed yeast (which I take from the trub) by pouring off the yeast in suspension. I've been trying to work out if I should make a starter with my reclaimed yeast or just add wort from my next boil and, after reading your post, I think I'll go with option 2.

 

[saccharomyces]

I don't really like using the slurry , all the dead yeast and **** . Better to use the fit healthy yeast from top cropping or if you forget or miss out , i make a tiny starter from a bottled batch (not too old ) it tends to be the fitter yeast imo .

Top cropping is always the preferred way to harvest yeast, as properly top-cropped yeast can be reused for hundreds, if not thousands of generations. However, top-cropping requires one to use a true top-cropping yeast strain or multi-strain. The strain from which US-05 was derived was a true top-cropper. What most amateur brewers do not know is that US-05 is not actually Sierra Nevada's proprietary yeast strain. Sierra Nevada acquired the yeast strain from the Siebel Institute of Technology in Chicago, Illinois. The Siebel accession number is BRY 96. The strain is originally from the old Ballantine Brewery in New Jersey where it was used for over one hundred years. The Ballantine Brewery was the sole remaining ale brewery in the United States when it shuttered its doors in 1972.

Here's what BRY 96 looks like when used in it's native environment:

 

[clibit]

Thanks saccharomo, I believe what you are saying, and it's partly cos it's pretty much what I do and I want to believe it! I know next to nothing and am pretty new to brewing, but I figured that sterilising a jar and putting some of the slurry in it is better than messing with it, esp when you don't know what you are doing! I then try to leave the junk behind when I pitch - but I like the idea of adding some of the fresh cooled wort and then allowing it to settle. I also figure it's a safer method than top cropping, less contact with your beer, and should work with any yeast - and provide more than one pitching quantity. I usually get two or three jars no problem. If I'm talking nonsense, please put me straight.