How Do I Know If My Harvested Yeast Is Good?

Hey,

I've been reading and searching the internet and it turns out that I didn't exactly follow the guidelines.

I bottled a batch today and planned on brewing another batch right after that, then pitching directly on the yeast cake. I've done this a few times before with success.

Well, after I bottled today, I had a family urgency come up and had to leave the yeast cake in the fermenter for several hours. I did leave some wort/beer on top of the cake. I can't brew tonight and will have to do it tomorrow night.

I sanitized a pint glass and a glas bowl with a rubber lid. I poured as much of the beer off as I could, then poured the rest in the glass & bowl. The bottom was pretty thick. So I poured some bottle spring water in the fermenter, swished it around, then poured the rest in the glass & bowl.

I put about 5 layers of sterilized Saran Wrap around the glass and the rubber lid on the bowl. Then I put it in the fridge.

I know there's nothing I can do about it now. I'm just wondering if there's a way to tell if it's still good before I brew tomorrow night.

Oh yeah.. I kind of do things backwards. I harvested the yeast, then I read the tutorials on how to do it..

Thanks
E

Only REAL way to tell is to make a starter. That's not feasible if your brewing soon, so you either give it a go....or not.

I kind of figured.

I guess I was hoping that someone here had a crystal ball.

Thanks,
E

Besides what Hammy said, why would you assume there'd be a problem with it?

If Brewing Beer From 45-Million-Year-Old Yeast is possible, why would anyone doubt your yeast wouldn't be?

Look at this thread from yesterday https://www.homebrewtalk.com/f163/my-yeast-isnt-dead-woohoo-237020/

Just so you know, there is a difference, a HUGE difference, between sanitized and sterilized. Sanitized means you used some Star San or something to kill most of the bad stuff. Sterilized means you used something that was autoclaved, which kills 100% of all life, rendering it sterilized. (Or a pressure cooker that can reach 15+psi of pressure, often called a "poor man's autoclave")

Since you probably did not sterilize the plastic wrap, the vessel to retrieve the yeast and the vessel to store the yeast. I can pretty much say that it is no good at this point. Use it if you want but be ready for an infection because it is a crap shoot if you get one. Even if you do not get an infection, without a starter that yeast is stressed out and will produce some odd off flavors because of this.

The only reason to store yeast is to make a starter. I have never heard of anyone harvesting yeast and not making a starter. Starters are easy to make the best/smallest ones are on a stir plate, which there are lots of DIY ones here on HBT.

Also I use this: http://www.mrmalty.com/calc/calc.html to tell me how big of a starter I need.

Zamial said:

Just so you know, there is a difference, a HUGE difference, between sanitized and sterilized. Sanitized means you used some Star San or something to kill most of the bad stuff. Sterilized means you used something that was autoclaved, which kills 100% of all life, rendering it sterilized. (Or a pressure cooker that can reach 15+psi of pressure, often called a "poor man's autoclave")

Since you probably did not sterilize the plastic wrap, the vessel to retrieve the yeast and the vessel to store the yeast. I can pretty much say that it is no good at this point. Use it if you want but be ready for an infection because it is a crap shoot if you get one. Even if you do not get an infection, without a starter that yeast is stressed out and will produce some odd off flavors because of this.

The only reason to store yeast is to make a starter. I have never heard of anyone harvesting yeast and not making a starter. Starters are easy to make the best/smallest ones are on a stir plate, which there are lots of DIY ones here on HBT.

Also I use this: http://www.mrmalty.com/calc/calc.html to tell me how big of a starter I need.

Click to expand...

Highly doubt this.

You're right about sterilizing vs. sanitizing, but I seriously doubt anyone is going to get an infection from plastic wrap, especially if he sanitized it. It's fine to harvest yeast without a starter, I did it the other day with success, and I have also done it in the past with success.

No need to scare the guy.

I agree with devilishprune, no need to scare the OP. I've basically done the same thing that the OP has done several times with great success, and no infections or sour taste even after storing the beer for six months. It works, just would suggest that he quickly washes the yeast slurry once before re-pitching, but he'll have plenty of yeast to re-pitch.

Don't pitch the entire amount of yeast, estimate your ML of yeast slurry using Mr. Malty's pitching rate calculator and only pitch that amount. You're fine, Relax, Don't Worry, Have a Homebrew...

I harvested last week and let the yeast sit overnight at room temp. Made a beer the next day and the yeast went to work so fast and so hard it blew the stopper out. If the yeast is ready to go it will not allow time for an infection to dig in. An infection can happen to a beer with alcohol already in it but this is very rare. The problem is typically going to be during the lag time. If your yeast is fresh it will take off quick and the bad bugs are going to have a hard time getting in there.

+1 on not listening to Zamial about contamination concerns. Every brewery in the world re-uses harvested yeast without making a starter. Especially if you are using it in a few days. It will be fine.

Thanks for the advice.

The reason I was concerned was because when I searched, I found posts like Zamial's. At first, I thought I was ok, but I ended up questioning myself. I feel better now.

I ended up brewing last night and used half of the yeast.

I haven't checked it yet, but I'm sure it's ok.

Thanks Again
Elias