pitching on to yeast cake?

[stu4stew]

Hi all sorry about this newbie question, but what does pitching on to yeast cake entail? Does it mean having wort ready to pitch the second u empty your primary for bottling/kegging? Or collecting the layer at the bottom of the primary and pouring that into worth and going with that as your yeast?

Just wondering as I am trying to set up my pipeline and being able to just pour wort in and combining bottling and brew day in one would be great.

Thanks in advance

 

[amandabab]

When I pitch on a cake, I just empty the fermentor on brewday and dump the new wort onto the existing yeast cake.

 

[hillhousesawdustco]

When I "pitch onto a yeast cake" (which I don't do all that often and I'm sure some zealot will harshly denigrate you for even considering) I siphon the fermented beer into a keg (or bottles or secondary or whatever you do). Then I stick that fermentor back into whatever fermentation chamber I'm using and get it the right temp and then within a couple hours I put the fancy fresh new higher gravity wort on top of it. So now the "new" wort doesn't need to be ready to pitch the absolut moment the "old" one is siphoned off, but it doesn't hurt.

If I do use a cake, I usually scoop out a couple spoon falls of yeast to make a starter with for another beer and assume that it also keeps from vastly overpitching the average beer that you put on the cake.

Give it a shot and see how your beer does. You are sure to get 16 different opinions on yeast handling around here.

 

[BigFloyd]

Depending on the gravity of the new wort being placed onto an existing cake, use a sanitized plastic spoon to to remove some of it. You can either harvest that or toss it.

If you've cold crashed the already-fermented batch, set the covered bucket aside at room temp to warm up some to get closer to the new batch pitch temp. If it's still over 10*F cooler than the wort when it's time to pitch, begin adding wort in small amounts and swirl it around the bottom of the bucket to slowly get the slurry temp up.

You can approximate what you leave in the bucket based on the amount of slurry a yeast calculator (like Mr. Malty) indicates.

 

[peanasky]

Another opinion on pitching on top of a yeast cake. Everything above is good advice, just remember your beer-order choice. Typically your "new" beer should be darker/higher gravity than the previous beer. You do not want to be pitching a cream ale on top of an IPA yeast cake.

Good luck, have fun, and remember, RDWHAHB

 

[jmf143]

There's no need to let the yeast warm up before pitching. "Cold pitching" is an accepted practice that produces results as good or better than having the yeast and wort at nearly the same temp. However, pitching warm yeast into cold wort may shock the yeast and should be avoided.

 

[BigFloyd]

There's no need to let the yeast warm up before pitching. "Cold pitching" is an accepted practice that produces results as good or better than having the yeast and wort at nearly the same temp.

I'll have to look into this.

If I can toss 5.5 gallons of 65*F wort straight on top of a yeast cake that's around 45-50*F without creating issues, so much the better.

 

[hillhousesawdustco]

I've always warmed mine up but actually that makes sense to me. The volume of the yeast cake probably isn't enough to really drop the temp of the overall beer, especially if you add slowly at first and stir.

 

[Calder]

Pitch on the cake and you can make good beer. Pitch on a quarter of the cake and make better beer.

If you pitch on a whole cake, you start with most of the yeast cells you need, so there is very little reproduction. This reduces the yeast created flavors and results in mostly old yeast having to do the job.

If you pitch on a quarter of the cake, you are closer to recommended pitching rates and the yeast will reproduce and fresh cells will do the work.

You don't have to pitch the same day. You can swirl the fermenter around to get the cake somewhat as a slurry, and pour into a sanitized container, and store in fridge. It can be kept very successfully for longer, but generally the recommendation is to re-use within a week.

You can wash it if you want. Washing does get rid of any old trub, but it is not necessary.

I have often pitch slurry straight out the fridge into room temp wort with no issues.

 

[Yooper]

Just some food for thought on why it may not be a good idea to do this: https://www.homebrewtalk.com/f163/why-not-pitch-your-yeast-cake-166221/

I normally just rinse/reuse my yeast and don't pitch on the full cake.

 

[BigFloyd]

Just some food for thought on why it may not be a good idea to do this: https://www.homebrewtalk.com/f163/why-not-pitch-your-yeast-cake-166221/

I normally just rinse/reuse my yeast and don't pitch on the full cake.

That's a thought-provoking thread. I had read that with interest about a month ago. When you get beyond the "never, ever, ever pitch on a cake without harvesting + washing. If you do, your beer is crapola." posts, it's a good read. That discussion helped me conclude that pitching on a whole cake would not be such a good idea unless the second beer is of a super-high gravity (think Imperial or Barleywine).

So, I run the numbers through Mr, Malty to see how much slurry is actually needed to get the # of cells required. Last time I did it (about 4 weeks ago), I removed almost 3/4 of an ESB cake before adding 1.057 OG stout wort. It lagged for about 6 hours and then fermented actively. The blow-off tube was attached, but not needed.

I still view it as an option that can be useful. I guess it really comes down to what yeast is below the beer I have coming out of the bucket, how clean the cake will probably be, what style is getting brewed next (and when) plus how it all fits into my sometimes limited brew schedule.