Yeast Washing

[quaboagbrewing]

Ended up bottling late last night and didn't have time to wash the yeast. I put a clean airlock back on the carboy and put it in the basement which is around 60 degrees figuring I'd just wash the yeast this afternoon after work. Any potential issues with delaying this procedure by a day? I figured as long as the carboy is sealed up I should be fine but since I normally do this all in the same day figured worth asking if this could be an issue.

 

[tagz]

there is potential for infection with all the air that was sucked in to displace the beer but you're probably fine.

 

[flars]

I'll often leave the yeast in the carboy until the next day. The yeast is covered with a layer of beer for protection. Haven't had a problem yet.

 

[broadbill]

I've done this and have had no problems. The larger issue as I see it is that yeast washing is a process that tends to get delayed, at least for me. I'll rack off a beer and often say "I'll wash the yeast later" only for the fermenter to sit a week or two without me doing anything.

FWIW, I think front-loading the process is a better option and provides healthier yeast. When I start with a new yeast packet, I'll make a larger starter than I need (say 1.5L instead of 1L) and save back a sample from it in a mason jar. That mason jar is what I'll use to make another starter the next time I want to use the yeast.

No slopping around big/messy volumes of yeast, boiling water to wash, separating layers, etc. Also, no worries about dead/pooped out yeast, carry over from one beer to the next, if an infection/contamination is riding along, etc.

 

[zeekage]

It's better to just leave a little of the beer in the carboy and swirl up the yeast cake. Then pour that into some sanitized mason jars and store it. Actually washing the yeast with boiled water can be more detrimental to the yeast health and increase the chance of infections. So i say you're fine right now, and just dump it into some mason jars soon. Skip all the work of boiling water, etc.

Don't take my word for it though: https://www.homebrewtalk.com/f163/cold-hard-truth-about-rinsing-yeast-boiled-water-451925/

 

[broadbill]

It's better to just leave a little of the beer in the carboy and swirl up the yeast cake. Then pour that into some sanitized mason jars and store it. Actually washing the yeast with boiled water can be more detrimental to the yeast health and increase the chance of infections. So i say you're fine right now, and just dump it into some mason jars soon. Skip all the work of boiling water, etc.

Don't take my word for it though: https://www.homebrewtalk.com/f163/cold-hard-truth-about-rinsing-yeast-boiled-water-451925/

Some more info:

https://www.homebrewtalk.com/f163/why-not-pitch-your-yeast-cake-166221/#post1921760


A quote:

For another, harvested slurry - unwashed yeast - loses viability rapidly. Tests have shown that approximately 25% viability is lost per every seven days spent in cold storage. If you must store the slurry longer than seven days, wash the yeast.

Harvesting post-fermentation slurry is all well and good if you are taking the yeast and going directly into another fermenter; otherwise viability drops quickly.

Pitching onto a cake is usually over-pitching, and you risk off-flavors from this process.

Either way, the think using post-fermentation slurry is a bit sloppy for the reasons I mentioned. The advantage of taking a sample of the previous brew's starter is you can "proof" the yeast for activity, its a fresh pitch with not impacted by the previous batch, has high viability, and you don't risk over-pitching as it is difficult to judge what amount of slurry = active yeast cells. Bob's post does a good job of approximating, but it is an approximation.

Just my position on the subject, after losing a batch because of poor viability of a harvest slurry.

 

[FuriousE]

I've done this and have had no problems. The larger issue as I see it is that yeast washing is a process that tends to get delayed, at least for me. I'll rack off a beer and often say "I'll wash the yeast later" only for the fermenter to sit a week or two without me doing anything.

FWIW, I think front-loading the process is a better option and provides healthier yeast. When I start with a new yeast packet, I'll make a larger starter than I need (say 1.5L instead of 1L) and save back a sample from it in a mason jar. That mason jar is what I'll use to make another starter the next time I want to use the yeast.

No slopping around big/messy volumes of yeast, boiling water to wash, separating layers, etc. Also, no worries about dead/pooped out yeast, carry over from one beer to the next, if an infection/contamination is riding along, etc.

Agreed. This is a technique I first read about here: http://brulosophy.com/yeast-harvesting/

It is much easier than doing it on the back end!!

 

[tagz]

Broadbill: I generally agree with you but do you have any hard info that post ferment yeast has lower long term viability than starter yeast?

 

[broadbill]

Broadbill: I generally agree with you but do you have any hard info that post ferment yeast has lower long term viability than starter yeast?

check out the link I posted; Bob has a bibliography at the end of his post, I'm assuming the info came from there (disclaimer; I didn't fact check!)

 

[broadbill]

interesting reading:

http://www.mbaa.com/districts/michigan/events/Documents/2011_01_14YeastStorageFermentation.pdf


Sounds like the bottom of a fermenter is pretty hostile to yeast and you want to do your harvest/cropping within 24 hours of attenuation, and preferably only the youngest cells (last to drop out, those that settle on top of the cake).

I don't think this is within the ability of the average homebrewer.

Assuming you do that, slide 25 recommends that harvested yeast is only good for 24-48(max) hours after harvest, assuming cooling and decarbonation (again out of the abilities of the average homebrewer).

 

[jwalker1140]

Yeah, but I think the linked pdf is geared toward pro brewers and at least some of the information may not be applicable to homebrewers. From what I understand, yeast autolysis and stress is mainly a concern when you have yeast at the bottom of a huge conical fermenter under many, many pounds of pressure. I recall Jamil and Palmer saying this isn't something homebrewers should worry about. YMMV.