adding new wort to old yeast cake?

[Vallka]

I have a yeast cake of 1056, it has been sitting in the carboy for a week now........can I just dump my next wort (24hr from now) right on it? Do I need to grander the yeast to a new clean carboy instead?

 

[Hawkbox]

I wouldn't. A week might be a bit long sitting out but moving it isn't going to make it any better. I normally wait till I have something to go on the yeast cake before I transfer off of it. Then I just pitch the next thing right on top of it.

 

[Vallka]

The yeast cake does have an airlock on it and is still bubbling co2 (once in a while) so the yeast should still be ok........right?

 

[Hogarthe]

As long as nothing got in you should be ok. You would lose some viability letting it sit but you have more than enough yeast to make up for it. Only downsides are possible something got in and you get an infection, or a lot of the yeast died and you get autoalysis off flavors. So not a best practice but if everything looks and smells normal you should be ok.

 

[Nosybear]

The yeast cake does have an airlock on it and is still bubbling co2 (once in a while) so the yeast should still be ok........right?

It should, key word being should. It's under a layer of its own beer and you haven't introduced air, should be okay. Again, key word is should. Remember, anything that's been growing in there since you racked off the beer has been growing for a week but gain, key word is should.

 

[Beer_Pirate]

I did this for a while until I had a batch go bad. Probably made half a dozen beers this way before one was off. Depending on your method of transfer, there's a chance something came in when you racked the last beer off and stuck to the walls of your fermenter, eating some residual sugars left behind.

 

[HighVoltageMan!]

I did this for a while until I had a batch go bad. Probably made half a dozen beers this way before one was off. Depending on your method of transfer, there's a chance something came in when you racked the last beer off and stuck to the walls of your fermenter, eating some residual sugars left behind.

Exactly, if it's transferred in a closed manner, you should be fine. If you use an auto siphon and draw in ambient air it may bring in with it mold/bacteria spores, wild yeast and bacteria. It goes back to sanitation and proper handling of yeast.

 

[Yooper]

Remember that pitching on an entire yeast cake is almost always a huge overpitch. I would pour the trub into some mason jars, and use 1/2 of a pint jar in the next batch (or use a yeast calculator).