What happens if you use the entire yeast cake?

I read that you typically want to use 1/2 - 1/3 of your yeast cake, depending on the gravity of your beer.

I’m curious what would happen to the fermentation length and process and
the result on the finished beer if you overpitched ? As an example, what if you used the entire yeast cake on an ale with an OG of 1040 ?

I made the mistake of doing this when I was fairly new to brewing and decided to use the cake of Wyeast 3787 from a batch of Patersbier to do another batch of Patersbier. Blow-off tube was clogged within 36 hours and the stopper finally blew out a little later. Wound up with krausen on the ceiling and a gallon of it all over the floor. The fermenter was at least 10 degrees hotter than the ambient temperature.

I’ve since only used an entire yeast cake once when I did a RIS with an OG of 1.105 on a cake of 1084 from a cream stout. I kept the ambient temp around 56 F or so and didn’t have any issues. Now if I’m going to reuse yeast I wash it, only pitch what I need and keep the rest in a jar for another batch.

if you step up OG successively from batch to batch, you can get really good results pitching on yeast cakes.
i like doing a mild (OG 1038), then a brown porter (OG 1050), and finally a robust porter (OG 1064) on the same yeast. yes, you’ll likely need a blow off tube. and i’ve only done this with British strains and 1056 (different beers). if you had stepped up from the Paters to a golden strong or something like that you may have been better off.

I do it frequently with great results. A 1.040 gets done in 3 days in my brewery. Although I still go 10-14 days in primary. I will soon be doing an experiment on identical batches; one keg’d and artificially carb’d with short conditioning period and the 2nd batch primary’d for 2 weeks, naturally carb’d for 2 weeks and then conditioned for 2 weeks. I want to know if you really can make GREAT beer in 10 days. I have my suspicions, but I’d like some unbiased data.
:cheers:

I’ve used entire yeast cakes a number of times, but only for very strong beers (1.090 or higher) or when the yeast was starting to get old, as in a month or more after harvesting it.

I’ve read that using too much yeast can give you some of the same flavor issues that not enough yeast can give, but I’ve never experimented so not sure if that is real. But if you have a full yeast cake, it isn’t much work to just pitch some of it at the amount that Mr.Malty suggests.