Page 1 of 1

Reusing Yeast In New Batch

Posted: Tue Nov 11, 2014 12:05 pm
by charlieb
Hey -

I'm sure there is a term for this but I don't know what it is. If I did, I would have searched for it and probably found my answer. So I will post the question
and see if I can get some help.

I will soon be cold crashing my fermenter in preparation for bottling. I will want to drop a new batch into this same fermentor once I've bottled the previous one.

I'm wondering if I can just dump and go? I'm thinking the new batch will get the yeast up and going again?

I will be using a similar gravity as well as using the same grains. Only difference will be the amount of hops this time but they will be the same hop variety.

Does anyone have any advice/tips on doing so? Anything I need to look for?

Thanks

Re: Reusing Yeast In New Batch

Posted: Tue Nov 11, 2014 12:45 pm
by Beer-lord
Most people refer to the used yeast at the bottom as 'yeast cake' and yes you can though there are opinions about doing this.
Personally, the few times I did this it was originally a bigger beer that I started on top of a smaller one. I also removed about half the yeast with a sanitizes spoon.

Others will use preboiled and chilled water (about 1/2 gallon) and wash the yeast then, after about 30 minutes of settling, using the top portion of the washed yeast only.

There are quite a few on this forum that start a new beer on the yeast cake on a regular basis that may have more helpful information on the best way to do this.

Re: Reusing Yeast In New Batch

Posted: Tue Nov 11, 2014 1:08 pm
by charlieb
Thanks for the reply.

I'm familiar with the term 'yeast cake'. I was wondering more if there is a term for doing what we are talking about?

In any event I like the idea of washing the yeast and then using that. If I don't start a new batch on this yeast I was going to wash it anyways.

Thanks for the suggestions

Re: Reusing Yeast In New Batch

Posted: Tue Nov 11, 2014 1:11 pm
by mashani
You can do it right on the yeast cake but it's always best to go in one or a combination of these sequences to avoid the previous batch from changing the second ones outcome too much.

Small beer to big beer (avoids massive overpitching - scooping out yeast helps too)
Less hoppy beer to more hoppy beer (avoids hops from batch affecting other batch in some way)
Light beer to dark beer (helps cover up any flavors that do creep in)

Re: Reusing Yeast In New Batch

Posted: Tue Nov 11, 2014 1:34 pm
by charlieb
I figured a few of those things Mashani but not all.

When you say go bigger - what are your thoughts? This batch has an OG of 1.062. 10 point increase? 20?

Re: Reusing Yeast In New Batch

Posted: Tue Nov 11, 2014 1:52 pm
by Beer-lord
I think you're good with jumping up 10-20. You would probably be ok with dumping the same size beer too but you don't stress the yeast as much if you go up a number of points.
The last one I did was a 1.062 beer and I put a 1.074 on top with no problems that I could tell. I did go from a pale colored beer to one a bit darker and hoppier.

Re: Reusing Yeast In New Batch

Posted: Tue Nov 11, 2014 6:16 pm
by mashani
I only do this when I'm going to make a strong dubbel or quad. So what I've always done is brew something like a 1.04ish-1.05ish patersbier/Belgian blonde, and then throw a 1.07ish-1.09ish dubbel/quad onto the yeast cake. This tends to make a fooking mess, but it makes good beer.

Re: Reusing Yeast In New Batch

Posted: Wed Nov 12, 2014 9:19 am
by charlieb
^If that's the case then I will probably just wash the yeast and not pitch all of it.

If I wash the yeast and pitch the same day, do you recommend a starter?

Re: Reusing Yeast In New Batch

Posted: Wed Nov 12, 2014 12:50 pm
by mashani
As long as you pitch enough cells, you should not need to make one. IE if you pitch the equivalent of say 1/3 of what you get from washing the yeast anytime in the following week or so, then you should get the viable happy cells of a hefty starter I think.

Re: Reusing Yeast In New Batch

Posted: Wed Nov 12, 2014 1:55 pm
by charlieb
1/3 Huh. That helps a lot as that was my next question lol.

I have a roughshod way of trying to measure out about 35ML which is the size of the whitelab vials.