Next batch right on the cake?!?!

So i have seen this phrased several times, example:

I used (insert yeast info here) and really liked it, i just got done with a (insert random brew here) and i just threw a (insert another random brew here) right on the cake.

Click to expand...

IF I am understanding this correctly, people are fermenting in their primary, racing it off to bottling/secondary and then throwing another batch right on top of that yeast sediment in their primary without cleaning.sanitizing at all... is that right, how safe is it? pros? cons? how long after racking off the last batch do you have to put in the new bath , should it be immediately or i sitting 30-an hour gonna hurt, this intrigues me!!!

There's still plenty of activity in yeast when you offer it new sugars to motivate it. Can't say much on the pros/cons, other then saving a couple dollars?

You got it right, just toss it in on top of the cake from the previous batch. Assuming you cleaned and sanitized on the first batch, your fermenter is good to go.
Pros: lots of healthy yeast; no lag time; fast and furious fermentation; no need to buy more yeast.
Cons: I can't really think of a con, however, it feels a little weird putting your brew in a gunked up fermenter the first time. It gets easier after you see how well it works.

As long as you keep a layer of the previous brew protecting the yeast, 30 hours should be fine.

This is the best way, IMO, to have a large "starter" for big beers.

If the primary is not infected (ie, the brew coming out is good) then nothing that's in it, however awful it might look (it was in with the beer that came out, remember?) is bad.

The sanitizing took place when you filled it the first time. So long as you also sanitized your racking setup correctly, it's sanitary. Normally the beer is not "random" - needs to be something that work with the yeast in question, and also one usually progresses to higher gravity beers, so that it's not overpitched.

As compared to "yeast washing" it provides a lot less opportunity for new infections - less handling. But it does look odd if you equate "grubby kreusen ring" or "trub" with "infection" - which is not a correct equation.

Dude, it rocks! As long as the first beer wasn't way stronger in flavor or "size" than the new beer, you shouldn't have any added flavors...




Yes, every time someone asks about pouring onto yeast cakes, I will put up this vid...

Glad you guys posted this. I am about to brew a simple pale ale which I am going to just toss on top of a yeast cake of Irish Red (White Labs California). I think I'm going to attach the airlock to a blow off tube just to be on the safe side, as shown in the video.

I am wondering how many batches can you pitch onto the same yeast cake?

I think I've heard 3-4 before the yeast start to "mutate", but I'm not sure what that results in... experiment for us?

Well... I had a brew night yesterday. Combined bottling what was in my primary (Irish Red) and brewing a batch of Pale Ale. I pitched the Pale Ale wort on top of the Irish Red yeast cake at around 11 pm EST. Woke up this morning and it is bubblin' away already. Combining the two activities was a big time saver too.

im thinking time saver as well, i wanted to do it yeaterday but my buddy didnt have tim and i was tired...

Pitched my nut brown ale with new yeast yesterday afternoon and had a healthy bubble with krausen when I woke up this morning. I think this method is great if you brew the same beer, or want to add your own twist to a beer, but don't see it as to much of a time saver. As long as you have healthy yeast, you're good- just my opinion. Happy brewing!

Time saver in the sense that I don't have tpo sanitize, but also to cut yeast cost, without having to spend the time wash/storing it.

I can get a better yeast to brew with and make it last 2-3 batches!

One potential downside of repitching on an entire yeast cake is overpitching (using too much yeast).

Proper Yeast Pitching Rates

If you use too much yeast, you may not get some of the normal flavors (ester profile) produced by yeast as they multiply. Without those flavors, you may not get the taste you're looking for in a beer.

You can take the yeast cake you have and then use the amount of slurry suggested by this tool:
Mr Malty Pitching Rate Calculator

That will allow you to reuse a portion of the yeast, save the rest and also get the ester profiles that will come from pitching an appropriate amount of yeast.

I've done it both ways, and I preferred the taste of the beer that was made with a portion of the cake.

I've pitched on half a cake (I split most of my batches into 2 smaller primaries) and yeah, it started bubbling within 2-3 hours. It's pretty slick, my LHBS jacked the price of Safale US-05 up to $4.50 so that's my way of getting back at the man

So is US05 a good yeast cause that is what almost all of the listermnn kits i have bought come with, i just assumed it was mediocre or bad yeast, was i way off?!?!