question for those who ferment & serve in same keg and reuse the yeast

[odie]

I've been fermenting and serving from the same keg for a little while. Been happy with the results.

I'm using a floating dip tube so that means all the yeast remains in the keg until the keg spits out it's final pint. When that happens I will usually brew another batch of the same or similar type beer and dump it in the keg a couple/few days later and let the old yeast take over.

My question is how long can I keep the empty keg and yeast cake before there are potential issues? I always keep the empty keg sealed and cold until then next batch goes in. But there is minimal, if any beer left inside to cover the yeast cake (as you would have in a mason jar of harvested yeast).

I overlooked a "used" keg in my cold storage that has been there perhaps 6 months. Still sealed all this time with the yeast cake still inside. I suspect it's still moist but been exposed to CO2 all this time.

 

[Abhishek Dewan]

I know a microbrewery pro who told they reuse up to 7 times. I personally have been using more than 1 year “old” yeast. I keep yeast bank in refrigerator and if I don’t use anyone in more than 2 months, I bring it out, add some sugar or juice etc to feed them. Keep out for 2 days and put back in fridge.

 

[odie]

well yes but is very different method of harvesting/reusing yeast.

 

[Dog House Brew]

I just bought 7 FlOTit dip tubes. I plan to be doing the ferment/serve. I’ve not given yeast much thought. I would say that I would remove some of the cake every time that I filled. I plan to fill 12 gallons? over 3 kegs. I think the cake will be too large for smaller gravity, but going with high gravity…might go with it. I’d rather have smaller volume and more robust yeast. Letting one sit, I could see pitching on an older cake. Covered with beer, I’d see 3 months no issue for me. Only way to know is try it. If my keezer had more space I could see storing and refilling.