Repitching Lager Yeast

I brewed 13 gallons of lager 2 weeks ago.  I split it between WY2000 and WLP802.  I plan on doing a double this weekend and using the yeasts for 2 different beers.  I’ve never re-pitched yeast.  I’ve always grown new yeast for every batch.  I was going to transfer to kegs after crashing.  Should I harvest after transfer and before dropping the yeast? I could put it in a jar until this weekend?  Can I harvest after dropping the yeast?  I planned on brewing, doing the transfer and using a portion of the cake on the same day.  I got thinking about what the cold 33 degrees might do to the yeast.  Not that it matters, but doing Bo Pils and Maibock this weekend.  Thanks

I’ve pitched right on to the cake many times with no issues.  Or scoop up a cup of slurry and use a newly sanitized vessel. The former is much easier and same results.

Dave, this suggestion comes up all the time, but the question it engenders is: is the whole yeast cake too much? Is it overpitching?

And it’s one of those controversial topics. Some say it is overpitching, and some say it isn’t. So regardless of how many of these threads I read, I never really know the answer.

I think running the same volumes in the vessel is overpitching the yeast, even with lagers.  It won’t kill the beer, but it will have a chance at making the beer a bit one-dimensional, because of the limited reproduction encountered by the cells (at least that has been my experience and what I attribute it to in these situations.).  I have gone to half a cake or better yet harvesting into a graduated 2 liter Ehrlenmeyer flask and measuring out the pitch using Mr. Malty (and adjusting for thickness encountered).  I have really liked those results.

So using the cake after cold crashing is OK?

I’ve pitched on to the cake numerous times with absolutely zero noticeable issues.  In fact, some really great beer.  But it’s up to you.  YMMV.

Using it in any capacity after cold crashing is just fine.

Dave

I agree.  It’s right up there with adding CaraPils to a Pale Ale for head retention.  ::slight_smile:

I can only speak from experience.  I’ve probably pitched on the cake (with light lagers no less) over a dozen times with excellent results.  Never a problem.

Dave

Please let us know how it turns out.

Just to make this clear for a noob, when you say “pitch on the cake”, do you mean “dump a new batch into the old fermenter without cleaning it out”?

I will probably remove part of the cake, and pitch in a new fermenter.  You could pitch into the same fermenter yes.  The buckets these are in are not large enough for my next batches, or I would.

the thinking is that if the bucket is ‘clean’ enough that the batch just in it isn’t contaminated than the next batch will be fine to. It seems to work out that way to. But the dried on gunk get’s really hard to clean after the second batch.

This has more of a chance for contamination than just pitching on the cake.  Be very diligent with your sanitation.

Dave

I have pitched on yeast cakes in the same fermentor up to 5 times with no adverse effects.

I agree with concerns about overpitching for ales, where you want some flavor contributions from the yeast, but I don’t worry about it for squeaky clean lagers. For my taste, lagers always taste better after months of lagering.

As far as the crusted gunk at the top of the fermentor, that’s what Oxyclean is for.  An overnight soak in hot Oxyclean solution takes care of that every time.

Would it still be “overpitching” if your previous beers O.G. was 1050 and your next beer is a higher gravity such as 1080?..The proper procedure is to go from lower to higher gravity when you repitch, so it probably isnt overpitching then…just my thoughts

Okay, you folks have talked me into it. I now have a batch of dunkel that I brewed a couple of weeks ago (1.055). I’m planning a Maibock in two more weeks (1.070) which should coincide nicely with the kegging of the dunkel. As a testiment to how much I trust y’all, I’m going to transfer the Maibock from kettle to cake. Thanks.

at 1.080 a full cake would for sure still be way overpitching. even at 1.100 it’s way overpitching.

I agree with Jonathon - practice good sanitation and follow a yeast calculator for pitch rate.  The most I ever repitched a yeast for lagers was somewhere in the mid 20’s (i.e., 20 times re-used).  No sanitation related problems encountered.  Then again, some yeast just don’t track that well beyond 4-5 repitches.

One thing I would do, though, is taste that beer coming off the primary to be sure that it is totally free from any off flavors before pitching the second batch onto the yeast cake.  And have a backup yeast ready (such as 34/70 sachets) just in case you need to use it.

Good luck and please let us know how it turns out.  I’m sure it will be just fine.

Dave