Repitching on yeast cake

I have a nice great Black Pearl Porter that is fermenting right now, prepared for a special work party in mid December.

Based on an overwelming response, I wanted to brew up a backup batch this weekend and was wondering about how I would go about reusing the yeast cake.

I've read the posts on yeast washing, and yeast freezing ( I have some of this London Ale in a Frozen Yeast bank), but was curious about what one could do if it was back-to-back.

Can I just rack off the existing, sanitize the next of the carboy, and pitch it right into the next batch, or does it need some kind of starter?

You've got it. The yeast cake is as good or better than a starter. I pitch right onto yeast cakes all the time, your fermentation will take right off.

Professor Frink said:

You've got it. The yeast cake is as good or better than a starter. I pitch right onto yeast cakes all the time, your fermentation will take right off.

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Seconded. I try to re-use all my cakes at least once, especially if it's an expensive liquid yeast.

Make sure you rig up a blowoff though, they go fast and hard.

Overpitch much, guys?

Kilgore_Trout said:

Seconded. I try to re-use all my cakes at least once, especially if it's an expensive liquid yeast.

Make sure you rig up a blowoff though, they go fast and hard.

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LOL ! This one sure did. I had a 1/2" going into a gallon jug- which it blew over, thought I was going to have to use a carboy as a blow off!!!

I don't usually use the entire yeast cake.

I sanitize a clean ale pail as usual, cool, rack wort, etc. Then I use a sanitized measuring cup, and scoop in 2-3 pints of thick slurry, and either wash or dump out the remaining yeast.

2-3 pints, with a measuring cup, should be pretty close to a very-healthy 1L starter.

But you know if you wanted to make a beer very very fast it is the best way to go - you will have terminal gravity in about 3 days

Ok, even with Chriso's 2-3 pints, that is well over Jamal's pitch rate of about 4 oz for this beer. Fast is good

"Fast" may not always be the best method. Making a starter of healthy, active yeast at the proper pitching rate will minimize lag time. But pitching on an entire cake does have its disadvantages. There's an archive of the Jamil show where Chris White comes in for the last 20mins or so (I think it is the Saison show). Anyway, yeast growth is an important part of the fermentation process. If you pitch a batch on a previous cake, you risk over pitching and the yeast may not reproduce at the same rate they would under optimal pitching volumes. This yeast reproduction contributes to yeast health, effectiveness, and flavor.

I know that cake pitching is common, but after listening to JZ and CW recommend caution, I would be reluctant pitch on a whole cake. Anyway, the show might be a good listen if you're interested.

I take half a pint of the cake, and add 2 pints of boiled and cooled water containing 4 oz of liquid malt extract. I agitate it to let in some air and leave for 3 hours. Then I stir it up well, allow to settle for 5 minutes, and pour the top half of the mix into my new brew. If the yeast cake looks and smells ok, ie firm and almost rubbery, I use it up to 5 times. If it looks like hundreds of colloidal spheres, I dump it and use fresh yeast.