Repitching on yeast cake

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brandona33

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This has probably been covered before, but I am still unsure I guess. I have a batch ready to be racked to secondary, and am brewing a recipe that calls for the same yeast the same day. After the primary is empty, except for the yeast cake, what are the next steps to get my cooled wort onto the cake?
 
That yeast cake is going to hyper start your fermentation. Make sure you can control the fermentation temps to keep it on the cool side of the yeast, so the temps don't get out of hand.
 
Rack some out and save it in a sterilized mason jar or two and put it in the fridge, then you'll have some for future brews and reduce the chance of over-pitching. :D
 
While the topic is up and the thread title isn't too specific, I'd like to ask a followup:

What's the longest amount of time that I could let a yeast cake sit before racking a new batch onto it, assuming that I put the lid back on the fermenter immediately after racking the previous batch off?

Ideally, this would happen the same day and the cake would not be exposed for more than an hour, but would it be alright to let the cake sit in the fermenter for a couple days? What if you left just enough beer in there to cover the cake?
 
Rack some out and save it in a sterilized mason jar or two and put it in the fridge, then you'll have some for future brews and reduce the chance of over-pitching

actually, I've had some really bad luck doing this and think I now understand why. When you remove yeast from the cake, you're bringing with it more than just yeast, maltose, and water - you're bringing starches and I guess, other things, that bacteria like. Everytime I've tried to 'harvest' yeast I've ended up with some off-flavor nasty yeast the next time around. So, on the advice of Asheville homebrewing supply in NC, i've started making large starters on just LME, pitching part of it, and saving the other part. Then I use this starter continuously, simply building it up and pitching a part, in consecutive brews. That way the original starter never sees anything but maltose, water, and yeast and the exposure time is minimum.

I have also had really good luck pitching right on top of the cake and I think the difference between doing this and harvesting/reusing is exposure to air/bacteria. Seems like it wouldn't be much but you should've smelled/tasted all the harvest yeast I just poured out. Thankfully I only used it twice and only had to get 10 gallons of off-flavor yeast beer down my gullet.


cb
 
What's the longest amount of time that I could let a yeast cake sit before racking a new batch onto it, assuming that I put the lid back on the fermenter immediately after racking the previous batch off?

Ideally, this would happen the same day and the cake would not be exposed for more than an hour, but would it be alright to let the cake sit in the fermenter for a couple days? What if you left just enough beer in there to cover the cake?

The most I've left one is a couple of hours, but as long as there's an inch or so of beer on top of it and you reseal the fermenter I think it would last for a few days with no issues.
 
What's the longest amount of time that I could let a yeast cake sit before racking a new batch onto it, assuming that I put the lid back on the fermenter immediately after racking the previous batch off?

I've gone anywhere from a couple hours to a couple of days. I ferment in buckets, so the beer is cold crashed to begin with when I rack my beer to kegs. When I'm done, I leave a small layer of beer over the yeast and put my airlock back on and leave the buckets in the kitchen if I am brewing that day. If not, they go back to the freezer where they sit refrigerated till I have a batch ready.

When the batch is ready, I carefully pull airlock and drop it in the sanitizer bucket, then I pull the lid, add the wort, then give the inside of the lid a spray of Starsan for good measure and put it back on loosely till I get the other bucket filled.

I then take them inside where I will inject O2 for about 30 seconds in each bucket, snap on the lid and plug in the airlocks.

It helps to go from lighter to darker beers as well as bigger beers.
 
actually, I've had some really bad luck doing this and think I now understand why. When you remove yeast from the cake, you're bringing with it more than just yeast, maltose, and water - you're bringing starches and I guess, other things, that bacteria like. Everytime I've tried to 'harvest' yeast I've ended up with some off-flavor nasty yeast the next time around. So, on the advice of Asheville homebrewing supply in NC, i've started making large starters on just LME, pitching part of it, and saving the other part. Then I use this starter continuously, simply building it up and pitching a part, in consecutive brews. That way the original starter never sees anything but maltose, water, and yeast and the exposure time is minimum.

I have also had really good luck pitching right on top of the cake and I think the difference between doing this and harvesting/reusing is exposure to air/bacteria. Seems like it wouldn't be much but you should've smelled/tasted all the harvest yeast I just poured out. Thankfully I only used it twice and only had to get 10 gallons of off-flavor yeast beer down my gullet.


cb

I do this all the time, I usually have 4-6 quart mason jars full of yeast. I've had no problems. The main thing is sterilze the jars and lids and immediately put in the fridge. If the batch fermented the chance of nasties being in there is minimal. I don't bother washing either, but you could do this to remove more of the stuff you don't want.
 
Out of curiosity, what are you brewing?

i am brewing an oktoberfest from a kit, then doing a pumpkin ale, both recipes using the same yeast. Figured I'd do the pumpkin last because I didn't know if the flavor would transfer over.

Fall beer time is a great time!
 
I have only done it once - granted I am still a new bee at this stuff. I can say through Howdy Doody Batman did the second batch take off.

I did a direct repeat of my mild and the second batch was burping at tree times a second in one hour. Burping so fast I could not count the individual bubbles after three hours and finished dead calm at 25 hours.

I have not yet tried the second batch as I still have a few bottles of the first to get through first but a friend did a side by side test and said there is a big improvement in the second batch.

I have one a night so in a few weeks I will be there.
 
I saved off the yeast cake out of the bottom of my secondary fermenter after brewing an Irish Red Ale into a spaghetti jar that I had ran through the dish washer, and sanitized.

It's been in the fridge for a day now, and there are 3 distinct layers:

At the bottom is a very dark brown layer about a 3/8 inch thick, then a sandy colored layer 3/16 inch thick, and on top of that is obviously the wort that was left on top.

Question: Which of the bottom two layers is the yeast?
 
Well that is weird. My sandy colored layer ends up at the bottom, which I am assuming is the yeast, as I've dumped off the beer and trub (middle layer) and gotten great results making a starter with what's left. However, from the yeast washing info I've read I've gathered that the yeast would be the middle layer.
 
I saved off the yeast cake out of the bottom of my secondary fermenter after brewing an Irish Red Ale into a spaghetti jar that I had ran through the dish washer, and sanitized.

It's been in the fridge for a day now, and there are 3 distinct layers:

At the bottom is a very dark brown layer about a 3/8 inch thick, then a sandy colored layer 3/16 inch thick, and on top of that is obviously the wort that was left on top.

Question: Which of the bottom two layers is the yeast?

The trub is the bottom- the yeast is the middle.
 
Today I racked a beer with the same yeast I wanted for the two batches of beer I brewed latter today. Mr. Malty said I only needed about 1/2 cup of the slurry per batch so I just scooped it out with a sanitized measuring cup. I have some extra fermenters so I didn't have to use the same one.
 
The trub is the bottom- the yeast is the middle.

Good info - thanks to everyone who responded.

I've read a number articles on this now, but one thing I can't seem to find is - How do you know how much to use?

Is there a way of measuring how much yeast you have?
 
Related question but a little off topic.

I have heard that when pitching onto a cake you want to pitch onto a cake that came from a lower gravty beer is this a good general rule?

I currently have 2 beers going. One is a Bee Cave IPA and another in an American Wheat (Both with S-05). I plan on brewing a Old Rasputin Clone this weekend which calls for an American Ale yeast. Which cake would be better to pitch onto? I know the American Wheat has much more trub and hop bits from the BK cause I didn't use a bag for them and I dumped everything into the fermenter. However the IPA should have less since I used a bag and kept most trub in the BK.

Which cake should I pour my Old Rasputin onto?
 
Plan to pour wort on top of a yeast cake. I am using the same kind of dark ale. Should be fine since it is the same recipe? Right?
 
Make sure your wort is cool enough when you add it or you will get to see explosive fermentation. Your yeast cake has way more than the recommended amount of yeast for the next ferment and will easily get out of hand.
 
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