Reusing yeast cake

[Reviled]

Hey guys, I re-use yeast cakes all the time, but generally what I do, is keg the batch, then dump onto the yeast cake ASAP...

What I was wondering, if I say, kegged the CAP i have, would I still be able to leave the fermenter with the yeast cake for a week or so before I pitch onto it? Or will I be risking it by doing this??

My thoughts are maybe the extra oxygen or something may stuff with it somehow? But im not sure...

[JoKing]

I just pour the slurry into a big old jar and leave that in the fridge until I need it. You wont need all of the slurry for another brew - like for a 1.050 Lager, you'd only need 200ml.

Chuck that into a starter to invigorate it - and pitch.... all good!

[jt]

Do you get the starter going the day before you brew, or do you use a stirplate on the day ?

[JoKing]

If I have the jar full of yeast, and I only harvested within a week: I pitch a measured amount straight into the brew - no real need to invigorate the yeast... For ales anyway.

If it's been over a week - up to 3 months, I make a full size starter and even chuck the stir bar in for good measure. It depends on the gravity of the brew - so I just use the pitching rate calculator for liquid yeast to match the gravity even though I'm re-pitchcing. I tip the liquid off the top before I pitch into the started (I use preboiled water to wash the yeast) before I put it in the starter. Then after the starter has fully attenuated, I refrigerate for a couple of days to drop all the yeast down, and when I'm ready to pitch I tip (and taste) the beer in the top (as this is usually some recovered wort) and pitch into the beer.

I'm sure everyone has their own techniques - this just works for me, and I'm yet to have an infection. I have underpitched a few times though - you can tell in the flavour, and in the attenuation.

[jt]

If I have the jar full of yeast, and I only harvested within a week: I pitch a measured amount straight into the brew - no real need to invigorate the yeast... For ales anyway

I'm quite interested in this, because I want to reuse yeast, but I don't want to spend the extra time on starters - and extra steps where my shabby technique can botch things up.
I presume you wash when collecting ?

I routinely have a yeastcake available midweek and brew again on the weekend so that would be ideal

[studio1]

over my last few brews I have timed my brew day to be the same day I empty my fermenter. I used mr malty - with the setting 'thick yeast solids' to calc. how much I need for my next brew. I use a sterilised graduated beaker to scoop up the yeast I need and dump it straight into my next batch - no washing. I can grab any more yeast if I want and pop into a Mason jar - normally though, I will have top cropped some into a mason jar for growing up in a starter later.

[JoKing]

I do wash.

The easiest way is to Autoclave (pressure cook) your collection jar - and put the lid on while it is still full of hot water. I just put that in the fridge and wait for it to cool down.

So, once I have kegged the beer - and the cake is sitting there, I tip the water into the fermenter, and mix it all up. After 5 - 10 mins, I tip the loose yeasty sludge into the jar and put the lid on.

Done.

Then after a few days - if I want to use that yeast again, I microwave a baby bottle with 100mls of water for 5 mins with the lid loosely on so the steam can get out. When done, I tip that water down the sink, and cool the bottle sown (with the lid on). I then get the harvested yeast, and tip the watery stuff off the top. Then, I pour the sludge up to my measure in the baby bottle. Then... I pitch into the wort, and within 24 hours - the yeast is making beer!

A few extra steps - and I'm saving dollars.

[jt]

A few extra steps - and I'm saving dollars

Thanks, I just need easy and if possible, foolproof steps, I know my limitations

[jt]

I then get the harvested yeast, and tip the watery stuff off the top

 

Hey Jo - I racked my pale last night, had a nice big cake so didn't bother adding water, just swirled the fermenter and poured off a litre of slurry and popped it in the fridge.

 

This morning, I had 3/4" (yeast or slurry?) at the top of the bottle, an inch of clear wort then the rest was slurry. That's when I should have taken the photo

 

That 3/4" at the top tasted yeastier than the slurry.

 

looks like these were settling in the wrong order - or maybe the saved slurry was still fermenting ?

[martin w]

i didn't think they could settle in the wrong order, is it in a sealed container? any excess gas when opened? did you definately hit fg?

[JoKing]

This happens all the time. It's pure yeast at the top, and I think it goes up there due to high levels of C02 in the beer. It is avoided by the addition of water to your slurry (as the residual sugar to yeast ratio so much higher that the fermentation continues).

[jt]

Yup, ok, thanks chap. So that would've been the yeast to use then ?

 

As the bottle warmed up it did firm up = your comment of fermentation.

 

Martin, I probably wasn't at the lowest FG. No pressure from memory when I checked it cold. But as the morninh went on and the bottle warmed it did start to firm up, not enough for any hiss on opening though

[jt]

OK so here's the piccy this time round. Racked my 1034 pale last night @ 1008 and saved pure a litre of slurry, no water dilution. The bottle this morning, out of the fridge and it has a bit of pressure on it