Pitching onto a yeast cake

[Neonsilver]

I'm very interested in doing this but I'm kind of curious which way I should go with it. Right now this is what I have fermenting. An RIS, an IPA, A porter and a gingerbread ale. I know that the gingerbread is out because it's spiced so that brings me down to three yeast cakes to use. I also need to brew a ton before summer because I can't brew then at all unless I used a swamp cooler which I don't have the room for. These are the styles I would like to make for my batches. I have five fermentors to use to get me up to where I want to be as well.

Dead guy clone - 2 batches
APA - 2 batches
AAA - 2 batches
English mild - 1 batch
Another IPA maybe a double - 1 batch
Kolsch - 1 batch
Baltic porter - 1 batch
American barleywine - 1 batch
Sweet stout - 1 batch
Scottish 80 - 1 batch
English pale ale - 1 batch

Which ones would work best for the yeast cakes I'm going to have soon? I was thinking the RIS could go towards the barleywine, the porter towards the baltic porter and then the IPA towards the DIPA. I almost forgot to mention, the RIS was done with S-05, porter with wyeast london ale (I think 1028) and the IPA was done with 1056. Then it's a question of what order should I do the other ones in. Thanks in advance for all of your help.

 

[bubbachunk]

How big of a beer is your RIS? In a big beer such as that the yeast may have been stressed and a new colony may not be a bad idea. As for the order I would go with similar styles with increasing starting gravities.

 

[Neonsilver]

The RIS should be over 1.100 if I did everything right. It has 12 lbs of DME in it so I'm sure that it's very close if not over. Also, for the ones that I'll be doing two batches of can I pitch the second one right onto the previous yeast cake?

 

[bubbachunk]

Yes you sure can just make sure to be sanitary and be at pitching temps before you put the next batch onto the cake.

 

[bknifefight]

Anything over 1.070, you should not reuse the yeast because it is stressed. Just keep the styles similar and keep stepping up the OG. For example:
1st batch - 1.040 Session Pale Ale
2nd batch - 1.06 APA
3rd batch - 1.08 IPA

 

[Neonsilver]

Alrighty, that makes a lot of sense and thanks again.

 

[Synovia]

Anything over 1.070, you should not reuse the yeast because it is stressed. Just keep the styles similar and keep stepping up the OG. For example:
1st batch - 1.040 Session Pale Ale
2nd batch - 1.06 APA
3rd batch - 1.08 IPA

I've heard that a lot, but is there any real evidence for it? Why is a 1.06 fine and not a 1.07?

 

[BackBayBrewing]

I've heard that a lot, but is there any real evidence for it? Why is a 1.06 fine and not a 1.07?

I'm with you Synovia. I think that if you used proper pitching rates when pitching your first batch, that yeast cake should be fine. If you are using .75 million cells per milliliter of wort per degree plato on the first pitch, the yeast should not be overly stressed regardless of OG. I would, an have repitched from beers with and OG over 1.080 and never had a problem. I believe this to be especially true if you are stepping up the OG over time as suggested above. If first pitch is in a 1.050, second pitch is 1.065, third pitch 1.075 and so forth, I think you will get great results.

Side note: I would recommend not pitching directly back onto the yeast cake in the fermenter. Instead I like to recapture the yeast and separate it from any trub and then repitch. That's just me though. This will also help to collect only the most viable yeast in there.

 

[bknifefight]

I would, an have repitched from beers with and OG over 1.080 and never had a problem

The stressed yeast added to the complexity of these beers Actually I don't know where I heard that or why I follow it but I definitely would not reuse yeast from something 1.100+ no matter how much yeast was pitched.

 

[Scimmia]

I'm with you Synovia. I think that if you used proper pitching rates when pitching your first batch, that yeast cake should be fine. If you are using .75 million cells per milliliter of wort per degree plato on the first pitch, the yeast should not be overly stressed regardless of OG.

It has more to do with alcohol content than anything. Alcohol is toxic to yeast, so more alcohol means more stress. You could very easily end up with yeast health issues.

The IPA could be a problem as well, depending on just how bitter it is. Isomerized alpha acids are not very good for yeast, either. Remember, the IPA style came about because they were adding more hops so that the beer would survive a long journey. Isomerized alpha acids are a preservative, they will coat the yeast/bacteria/etc and inhibit growth.

 

[BackBayBrewing]

It has more to do with alcohol content than anything. Alcohol is toxic to yeast, so more alcohol means more stress. You could very easily end up with yeast health issues.

This makes a lot of sense. I haven't noticed a problem, but I would say the highest OG I've repitched from was probably 1.085 give or take a few points. I've done this a few times and not noticed problems, but I think next time I might do a fresh pitch for half the batch and a repitch for the other half to see what the differences are.

 

[Neonsilver]

Side note: I would recommend not pitching directly back onto the yeast cake in the fermenter. Instead I like to recapture the yeast and separate it from any trub and then repitch. That's just me though. This will also help to collect only the most viable yeast in there.

Are there any really good articles on how to properly do this? I'm very interested in this process and it's probably time for me to add a new skill to the list.

 

[BackBayBrewing]

The link below gives the general idea. There are many variations on this approach, but this will get the job done. Most important thing when working with yeast... be VERY careful about sanitation. Boil anything that will come into contact with the yeast.

https://www.homebrewtalk.com/wiki/index.php/Washing_yeast

 

[Neonsilver]

Thank you very much and that seems pretty simple. I might have to go to the store this weekend and get some supplies.

 

[Synovia]

It has more to do with alcohol content than anything. Alcohol is toxic to yeast, so more alcohol means more stress. You could very easily end up with yeast health issues.

Right, but then why aren't people having yeast health issues in the RIS? I mean, at some point, its at 7% alcohol, and more fermenting needs to be done.



All I know is, every time I've pitched on a cake, no matter how big the previous beer was, its taken off like a rocket. Doesn't sound like unhealthy yeast to me.