Recycled Yeast Cake.

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spriolo

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Last night I re-used a yeast cake in my primary for the first time ever. I racked a batch from my primary bucket to a secondary carboy and figured I'd see if I could save $5 (SafAle S-05). I pitch a freshly boiled batch right on top of the yeast cake.

After racking to the secondary I placed the primary bucket lid and air lock back on the bucket. I figured it was clean and bacteria free since the taste and smell of the beer was fresh and hoppy. It only sat for 5 hours or so while I messed around with the new all grain batch.

I made sure the new batch was chilled down to 75*-ish (I normally ferment at basement temps of 72). Just for good measure and for extra drama (SWMBO was watching) I aerated the wort by lifting the boil buck way in the air while pouring... :) It made a big woosh and splashed around inside the primary like it was being blended. She loved it. :D

The morning after? The air lock is about to pop off the top. Those yeasties are going like starved mad men!!!
 
Massive overpitch! Fun, though, isn't it?

Next time I'd only use part of the yeast cake (mrmalty includes pitching rates for repitching from a yeast cake; e.g. for a reasonably big 1.075 brew you only want about 125ml of slurry).

You can save the rest, either as-is for relatively soon reuse, washed for use in the next couple of months--see the sticky for yeast washing illustrated.
 
Thanks for the mrmalty tip.

The previous batch's OG was about 1.050, this one is 1.060... Can I assume because this is a second generation AND it's working on a 1.060 these yeasts are going to be tired out?

(if there is such a thing?)
 
Thanks for the mrmalty tip.

The previous batch's OG was about 1.050, this one is 1.060... Can I assume because this is a second generation AND it's working on a 1.060 these yeasts are going to be tired out?

(if there is such a thing?)

1.060 is big but not huge. I'd be okay reusing it, but I'd prefer to use a smaller beer's cake if possible.
 
That's good news. This seems to work well. I might rack to secondary, wash some of the yeast and leave ~1/2 cup (125mL) for the next batch then. :) 3rd Generation Slurry I guess.

Seems like you could reduce your costs this way (if you are happy with the yeast you have)
 
That's good news. This seems to work well. I might rack to secondary, wash some of the yeast and leave ~1/2 cup (125mL) for the next batch then. :) 3rd Generation Slurry I guess.

Seems like you could reduce your costs this way (if you are happy with the yeast you have)

Yeah, I have a couple of jars of 3 of my favorite yeasts tucked in the fridge. For a yeast I brew a lot with, I'll get 10+ brews out of one smack pack. For stuff I use less often, I'll usually plan on 2 brews with it in close-ish proximity (within a couple of months)to at least split the cost, unless it's something really unusual when I'll just eat the cost.

I've also got some Orval dregs cultured up for a forthcoming brew; $6 for a really good beer plus a brett culture seems better than $8 for a brett smack-pack.
 
Update: I just racked this batch into the secondary (it's been a week or so) and the attenuation of the yeast is only 67%! I was expecting 80% like the last batch I used this yeast on.

OG 1.060
Secondary Ferment Rack SG: 1.020

Any thoughts?
 
Thanks for asking. :)
Grains
Weyermann Light Munich (2 row) 10 pounds
Muntons Crystal (2 row) L55 1 pound

Water
Mash 3.4 GAL
Sparge 4.8 GAL
Grain Absorb 2.3 GAL
Total wort before boil 5.9 GAL

Water Procedure
Mash at 155*F
Fly Sparge at 170*F

Hops
Cascade 2 OZ 60 Minutes
Cascade 1 OZ 30 Minutes
Cascade 0.5 Dry

Yeast
Pitched cooled wort over entire yeast cake of SafeAle S-05
 
Check it out.

I was reviewing my copious notes (yes I'm a beer numbers geek) and saw that my last batch with the same yeast (as the title says this is a recycled yeast cake) had an SG when I racked to secondary of 1.022. I was disappointing in the performance but assumed it was because I mashed at 165-ish. I was experimenting with higher mash temps (lower sugar).

This time my mash temp was lower yet the yeast performed the same way (after only 7 or 8 days in the primary). In the past I've used S-05 right out of the packet and it has consistently had an 80%+ attenuation. Could it be that this packet of yeast is just lazy?
 
was fermentation finished when you racked at 7-8 days?

Possibly not. my usual use of S-05 is that after 7 days it's done. I check the SG 2 weeks later when I get ready to bottle and rarely does it read differently. I'll have to take a sample and check it out (maybe a few days from now... give it some time to continue fermenting in the secondary).
 
Possibly not. my usual use of S-05 is that after 7 days it's done. I check the SG 2 weeks later when I get ready to bottle and rarely does it read differently. I'll have to take a sample and check it out (maybe a few days from now... give it some time to continue fermenting in the secondary).

You don't rack to secondary until it's done! Doesn't matter if it takes 4 weeks, or 6 weeks. It needs to be finished before racking off of the yeast cake.

7 days is not enough time for fermentation to complete. I don't care what the hydrometer says, it needs more time. 3 weeks should be minimum.
 
bja is correct. you should leave the primary alone until the gravity is solid for at least 3 days. i usually wait at least a week or two after i think it's done to rack to the secondary.

as an example, i was following an old Papazian recipe for a cherry ale using real sour cherries. it said to ferment for 5 days and then remove the cherries. being lazy, instead of scooping out the cherries, I just racked the beer to the secondary. what was once a vigorous fermentation stopped almost completely. in fact, did stop and left my gravity at 1.020--way too high.

in the end, i had to do a yeast starter with a Nottingham packet in my fridge and add some yeast nutrient to get the fermentation going again. (pitching after 15 min of rehydration according to the Nottingham instructions wouldn't work because of alcohol already present in the beer, i had to give the yeasties a fighting chance with a starter and nutrient!). BUT, after all that hassle, it got down to 1.005 and is a very fine product.
 
i don't know the specs on S-05, i only used it for maybe my first batch. but i would recommend, if you have another packet, to do a starter and let it get going for 24 hours. once the starter is ready, pitch the yeast and also add some yeast nutrient to help them survive the already alcoholic environment you are sending them into battle. i prefer Nottingham as my bail out, but if you have extra S-05 that's probably good too.
 
This is a really good point. I should have measured a couple of times to make sure it was finished. ~kicking myself now~ I've cranked out 4 batches (5 GAL) in 4 weeks and I let my process get clouded by the calendar and not the condition of the beer.

I'll have to tinker with it and see how much the fermentation halts even though there is plenty of sugars in there. If anything, in about 4 or 5 weeks, I'll be enjoying some nicely sweetened ale.

As a last thought, I appreciate bja's encouragement to put a minimum amount of time on the primary, but I've learned from this experience that measuring is really the only true way of getting the product you want in the amount of time it actually needs (not some hypothetical 3 or 4 weeks in the primary rule).

Live, learn, and drink good beer; right?
 
measuring is the key. generally, i like to wait until the krausen goes away and then to wait another week. i'll likely know the day i want to rack, usually a saturday or sunday. so on thursday or friday, i will take a reading. then, i will do another that weekend to make sure things are steady. but for most beers that take a week to ferment, i'll leave two weeks in the primary unless i'm trying to work out some diacytl or off flavors from too high ferment temps.

good luck, and i'm sure you will be fine with the beer, even if it's a little sweet! but i encourage pitching the backup yeast per my earlier post if you want it to be a lower gravity...
 
As a last thought, I appreciate bja's encouragement to put a minimum amount of time on the primary, but I've learned from this experience that measuring is really the only true way of getting the product you want in the amount of time it actually needs (not some hypothetical 3 or 4 weeks in the primary rule).

Any beer will benefit from an extended stay on the primary, even if its long done fermenting. Patience is the key here. I realize that in the beginning it's hard to wait. But as you get more and more brews under your belt (pun intended), it will get easier to sit back and allow your creations to mature.
 
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