When to NOT wash and reuse yeast

[BradleyBrew]

Hello, I'm sure this has been discussed before but I was looking for reasons NOT to wash and reuse yeast. I am a newb to washing yeast and I have a Wyeast British Ale yeast that has been through two brews now. The first was a Newcastle clone at 5% and the second is a Coopers Extra Foreign Stout at 7%. No problems with the yeast it has been fast, aggressive, and chewed up both worts. Just curious when the yeast has ran its course?

I understand if you had issues with stuck fermentations or an infection this would be grounds to terminate that strain. Any other reasons?

 

[bullinachinashop]

High gravity beers and highly hopped beers. Improper sanitation, etc.

Bull

 

[Nateo]

If you're having infections or stuck fermentation, you've already gone too many generations with the yeast. Most brewers would try to toss the strain before issues came up so they don't ruin their beer.

Fast and aggressive fermentation may not mean the best possible fermentation, but this is impossible to say without tasting the beer for faults.

You've hit on the two main reasons not to wash yeast (poor performance and bacterial load), but another reason is flavor drift. The 5th batch with the yeast may not taste like the first. But that's a bigger problem for pro brewers who are trying to replicate recipes over and over.

 

[Nateo]

High gravity beers

Bull

I agree strictly from a practical standpoint for a homebrewer, but it's interesting that some of the smaller Belgian and American craft breweries only make "high gravity" beer and still reuse the yeast.

 

[BradleyBrew]

I am currently drinking the Newcastle and it is fine... The Coopers is currently in its 4th week in the primary and I plan to bottle later this week. It was around 60 IBU's and 7% abv. Would this classify as a high gravity brew? I planned to wash the yeast and then repitch into a starter? This would only be the 3rd generation.... Thanks for the quick response!

I havent had any problems with this strain I'm just curious what would warrant the "retirement" of this strain and to start over other than a infection or stuck fermentations...

 

[Nateo]

1.060 is generally the start of "high gravity" with regards to yeast rinsing.

The risk of infection rises with each batch, but you won't know when you'll get an infection until you do. So, I would retire the yeast when the risk of infection becomes greater than you're comfortable with. Like cashing in your chips at the casino. If you go long enough, you'll go bust and have 5 gallons of ruined beer. I'm more conservative and only reuse a few times before starting fresh.

Some people can rinse and reuse yeast for dozens of generations without any problems, just like some people can smoke a pack a day and live to be 100. It may work for some people sometimes, but is not necessarily "best practice."

 

[osagedr]

You have to do what you're comfortable with, but I certainly wouldn't hesitate to wash and re-use at this point.

 

[BradleyBrew]

thanks for the feedback... I think I will go ahead and wash and store the yeast as I do not have any plans to use that yeast in the coming next few weeks. Will the yeast in storage tell you if it has been infected.. smell, taste, look, etc?

 

[ChillWill]

Maybe, you'll have a better idea when you make a starter though and smell/taste it.

 

[Turner5]

Why does the gravity make a difference?

If you're making a starter the yeast will reproduce so it's not like the majority of the yeast in the starter have ever been exposed to the effects of a high alcohol environment.

Edit: Never mind, not sure I agree but I can understand a little better.
https://www.homebrewtalk.com/f163/yeast-washing-high-gravity-beer-239521/

 

[moti_mo]

Why does the gravity make a difference?

If you're making a starter the yeast will reproduce so it's not like the majority of the yeast in the starter have ever been exposed to the effects of a high alcohol environment.

Edit: Never mind, not sure I agree but I can understand a little better.
https://www.homebrewtalk.com/f163/yeast-washing-high-gravity-beer-239521/

mutation - when yeast get stressed, crazy things can happen. I'm not sure what the stress is for highly hopped beers, but I can empirically say that I've only had a couple of beers where I re-used yeast and got noticeably poor results, and they were both from yeast that I washed and re-used from heavily hopped beers. I stopped that practice long ago.

 

[Zamial]

mutation - when yeast get stressed, crazy things can happen. I'm not sure what the stress is for highly hopped beers, but I can empirically say that I've only had a couple of beers where I re-used yeast and got noticeably poor results, and they were both from yeast that I washed and re-used from heavily hopped beers. I stopped that practice long ago.

The way i understand yeast and highly hopped beers is that the hops will alter the structure of the yeast's cell walls, in a bad way.

I am not a yeast guru and have just started washing and reusing yeast myself. I am also very close to having everything I need to start a yeast ranch in my freezer. From the HBT knowledge pool, I believe that the "make a starter" should apply to every brew.

 

[1Mainebrew]

Have you thought about culturing the yeast from the bottom of a bottle of your Newcastle clone? Start with a small starter like 1-2 oz H2O with 1-2 oz DME and then step up to a full size starter.... Just a thought that would prevent you from getting a yeast harvest from a sub-optimal environment.