Sloppy Old Slurry Starter vs. Fresh Yeast | xBmt Results!

[brulosopher]

I appreciate simple methods that produce good beer, plus I’m cheap. I’ve been curious about how well unrinsed yeast harvested from the bottom of a fermentor that was stored for a bit would perform compared to fresh yeast, particularly after the Sloppy Slurry vs. Clean Starter xBmt. I put this one to the test and the results are in!

exBEERiment | Impact Using Old Yeast Slurry Has On A Vienna Lager

[klickitat_jim]

I like this one. Good choice on beer style for this comparison. Im not surprised by any of the findings.

[ynotbrusum]

That is as I would expect, based on my experience.  Next time try a straight slurry repitch (I schedule my lagers for when my beer is ready to rack, so it literally is re-pitching minutes after harvest).  Also I wonder how many generations out before a difference shows up, if any.  The most generations I pushed it to  on a yeast strain was a bit over twenty repitches on a WLP 800 house lager brew.  Never a problem, but eventually I just gave up using the yeast to move on to something different…

[system]

I have been saying that yeast rinsing is little more than home brewer voodoo for years.  Yeast cultures do not need to be physically clean.  Yeast cells need to remain biologically clean, and the best way to ensure that they do so is to leave them in their native environment.  The low-O₂, low pH, ethanol laden environment that the culture produced during fermentation is more toxic to invaders than it is to the culture itself.

[brulosopher]

I have been saying that yeast rinsing is little more than home brewer voodoo for years.  Yeast cultures do not need to be physically clean.  Yeast cells need to remain biologically clean, and the best way to ensure that they do so is to leave them in their native environment.  The low-O₂, low pH, ethanol laden environment that the culture produced during fermentation is more toxic to invaders than it is to the culture itself.

My bigger concerns have always been flavor carryover from hops and trub and/or “stressed” yeast from higher OG fermentations. I still plan to test both of those more specifically, but my concern is certainly waning.

[system]

@brulosopher

My bigger concerns have always been flavor carryover from hops and trub

This fear is overblown in the home brewing community.  Plus, brewers who are harvesting yeast should at least attempt to limit the amount of organic material that enters their fermentation vessels during cast-out.

and/or “stressed” yeast from higher OG fermentations.

No amount of rinsing is going to fix the higher OG fermentation problem.  The cellular damage is done before the beer is racked.

[seyahmit]

Interesting read. I completely agree about keeping as much of the trub and hops out of the carboy as I can when I plan to repitch yeast. I will let the wort settle for 20-30 minutes after chilling to let it all settle out.

[denny]

@brulosopher

I have been saying that yeast rinsing is little more than home brewer voodoo for years.  Yeast cultures do not need to be physically clean.  Yeast cells need to remain biologically clean, and the best way to ensure that they do so is to leave them in their native environment.  The low-O₂, low pH, ethanol laden environment that the culture produced during fermentation is more toxic to invaders than it is to the culture itself.

My bigger concerns have always been flavor carryover from hops and trub and/or “stressed” yeast from higher OG fermentations. I still plan to test both of those more specifically, but my concern is certainly waning.

As you found, there is no worry about flavor/color carryover.  I’m a yeast abuser and have regularly reused yeast from fermentations in the 1.075-80 range, which is much higher than “conventional wisdom” says.  I try not to do that these days, and certainly wouldn’t advise others to do it, but I had no problems because of it.

[johnnyb]

@denny

@brulosopher

I have been saying that yeast rinsing is little more than home brewer voodoo for years.  Yeast cultures do not need to be physically clean.  Yeast cells need to remain biologically clean, and the best way to ensure that they do so is to leave them in their native environment.  The low-O₂, low pH, ethanol laden environment that the culture produced during fermentation is more toxic to invaders than it is to the culture itself.

My bigger concerns have always been flavor carryover from hops and trub and/or “stressed” yeast from higher OG fermentations. I still plan to test both of those more specifically, but my concern is certainly waning.

As you found, there is no worry about flavor/color carryover.  I’m a yeast abuser and have regularly reused yeast from fermentations in the 1.075-80 range, which is much higher than “conventional wisdom” says.  I try not to do that these days, and certainly wouldn’t advise others to do it, but I had no problems because of it.

That is good. The first step is to admit you have a problem!

[brulosopher]

@brulosopher

My bigger concerns have always been flavor carryover from hops and trub

This fear is overblown in the home brewing community.  Plus, brewers who are harvesting yeast should at least attempt to limit the amount of organic material that enters their fermentation vessels during cast-out.

While I don’t intentionally rack a ton of kettle trub to my FVs, I don’t worry too much about a moderate amount making it in. The slurry pitched beers have still come out okay.

@denny

As you found, there is no worry about flavor/color carryover.  I’m a yeast abuser and have regularly reused yeast from fermentations in the 1.075-80 range, which is much higher than “conventional wisdom” says.  I try not to do that these days, and certainly wouldn’t advise others to do it, but I had no problems because of it.

I certainly have some high OG slurry xBmts planned, I’m feeling cautiously optimistic

[beersk]

Good experiment, enjoyed reading the results. It is rather annoying how long it takes for fresh dry yeast, even rehydrated, to take off. It works so much better upon repitching.