Rinsing yeast process ... Why not do this?

[EagleDude]

From what I understand of JZ's process, you collect the trub, store it and let the yeast settle, pour off the liquid (beer), add sterilized liquid (boiled and cooled water), shake, let sit for 15 minutes, then pour liquid/yeast suspended portion back into the new wort. Pretty simple ...

If I am brewing the same beer as the one that the trub was collected, why would I need to pour off the liquid just to add liquid back? I would think that I could just swirl the settled yeast back into solution, let sit 15 minutes, and pour the suspended yeast/beer solution into the new wort. The dead stuff will still settle out first and the added beer isn't going to add any off flavors since it is the same beer anyways. Any reason not to simplify the process as suggested?

[Ozwald]

From what I understand of JZ's process, you collect the trub, store it and let the yeast settle, pour off the liquid (beer), add sterilized liquid (boiled and cooled water), shake, let sit for 15 minutes, then pour liquid/yeast suspended portion back into the new wort. Pretty simple ...

If I am brewing the same beer as the one that the trub was collected, why would I need to pour off the liquid just to add liquid back? I would think that I could just swirl the settled yeast back into solution, let sit 15 minutes, and pour the suspended yeast/beer solution into the new wort. The dead stuff will still settle out first and the added beer isn't going to add any off flavors since it is the same beer anyways. Any reason not to simplify the process as suggested?

Yes, there's a couple reasons. The left over sugars along with the fermented sugars can lead to spoilage. If you've ever done a starter, let it floc & then just sit there, you've seen the liquid slowly become darker. The braver souls who've tasted this know the sourness & funk can only mean brett, lacto, pedio & who knows what else have invaded. If you rinse, let settle, decant & repeat a second time you'll have a yeast sample that can sit unspoiled under sanitized water for a significantly longer time. I have one that I've had in the back of the fridge for roughly 20-21 months now; I can see the slow decline, but I guarantee that I could brew with it given a few days notice. I've had the same strain go bad in a few weeks after I finished a starter & placed it in the fridge.

Mainly, you want that sterile water rinse to get rid of bad yeast cells & contaminants, such as trub and the like. In my process I rinse and do cuts during the process:

Collect your yeast, let settle.
Decant & add your sterile water. Swirl.
Let set for 5 minutes or so. Decant into 2nd sterile container leaving behind most flocculant yeast.
Allow to settle for another 25-30 minutes, decant & discard the top liquid. This is the least flocculant yeast.
Change the times to get the cut you want out of your yeast.

Also, you rarely pitch directly back into fresh wort rather than doing another starter to get the best count of healthy cells. The more you reuse yeast, the more you have to be careful of the mutations, etc. The more generations on my yeast, the more careful I am to the cuts I'm using (I'm pretty damn picky & tend to select <5ml to grow for my next 12g batch).

I don't see any reason why your process wouldn't work, but I also see the reasons why I take the extra steps for starters/storage.
(BTW, I'm a little tipsy after a real bad morning at work & then coming home to a bitchy lady. Take your salt with a grain of 'Shut the fuck up, Lee'. She certainly has.)

[Quin]

JZ discussed rinsing with water to use for the following batch (not the one you're pitching into now) on the idea that it is healthier for the yeast to store in a lower alcohol medium than beer. One of the earlier White shows, Chris White indicated they didn't have very good results with storing yeast in water for repitching.

BTW, I don't rinse at all and leave the yeast on the beer, but I try to brew again within 7 days.

The darkening mentioned in the above post should be from oxidation. I would hope that you don't have enough pedio/lacto to change the flavor of the starter.

[Ozwald]

The darkening mentioned in the above post should be from oxidation. I would hope that you don't have enough pedio/lacto to change the flavor of the starter.

Now if I was sober at the time, I might have said this.
The amount of alcohol in a starter is really low. It's not enough to protect your yeast from other bugs eating the residual sugars they left behind. So when it's allowed to sit on beer for a while (didn't know that darkening was oxidation, thanks for that) it's more susceptible to infection than if it's sitting under deoxygenated, sterile water (pre-boiled, sealed & cooled).

This is what I've been doing. I grow them up in a series of growlers, 1g jugs & 3g carboys. At the peak of my production last spring/summer I was doing 1-3g all-grain starters 6 days a week, had 20+ growing cultures of 5 strains of yeast (2 brett) at any given time. They got rinsed periodically through the process & one final time before they went into a pint-sized ball jar in the back of the fridge. I always would throw that into another starter & pitch at high krausen. If I didn't use it within 8-10 weeks I'd pull the jar, do a starter, rinse & jar it back up. I'd have to say the biggest pain in the ass was the labeling & paperwork to keep everything straight.

[EagleDude]

Well ... I was specifically referring to brewing a batch, collecting the trub/beer, and using the liquid (beer) already collected with the yeast to do the dead/live yeast separation. With my process, there wouldn't be any storage involved. Transfer batch 1 into kegs, collect the trub/yeast, separate dead yeast out (swirl and let settle a few minutes) and pour the yeast into the new batch the same day. I am getting the impression that the water is doing more than just providing a medium for the dead yeast to fall quickly through. If so, I guess I should use water and rinse. If not, I still don't see any reason not to use the beer collected with the yeast as long as the solution is not too thick. Once again ... one batch to the next with no storage period.

[Ozwald]

I am getting the impression that the water is doing more than just providing a medium for the dead yeast to fall quickly through. If so, I guess I should use water and rinse. If not, I still don't see any reason not to use the beer collected with the yeast as long as the solution is not too thick. Once again ... one batch to the next with no storage period.

Few thoughts.
I don't see anything wrong with what you're doing. It should work fine, but at the same time it's not rinsing.
I "always" pitch active. I've forgotten/didn't have time here and there (& noticed the fermentation wasn't as good), but I'm pretty good about making a starter the day before. If I'm going to make a starter with some harvested yeast, I want the yeast not the other things I harvested (including the old beer). Sometimes this can take multiple rinses. Also if I have a large sample, I can cut the yeast with rinses, the same way someone would cut heads and tails while distilling. I want a certain cut of that yeast so when I make the starter the new cells are going to be more like the ones I harvested - so I want to get rid of the over & under floculant mutants. This can take multiple rinses. I've got to cut this short since I've been interrupted 5 times since I've started this - long story short, even batch to batch I'd rinse with pre-boiled h2o & get it active with a starter. Cheers.