re-using yeast/lees

[mpmn04]

I just racked a FESTA BREW kit from the primary fermenter bucket into my carboy, and was wondering if I could start another kit by just pouring the wort from another FESTA kit into the bucket containing the yeast/lees from the 1st batch (and not add the yeast from the 2nd kit).

Is this do-able?

[LiverDance]

yes if your sanitation is good and you do it right after you transfer the first. It'll be more yeast than you need in the new batch but I've done it before.

[CorneliusAlphonse]

ive done that before, typically i've done it with liquid yeast or some other yeast that I want to make the most of. if you're just using us05 or something, it rarely seems worth doing, but then again it lets you use the fresh pack of yeast somewhere else!

one thing to note, fermentation will likely take off like a rocket, make sure the temps stay under control (easy this time of year)

[GuingesRock]

This time around the yeast will need oxygen (dry yeast from the packet doesn't so much). Might have to shake, splash or whisk with sanitised whisk or something.

[RubberToe]

Actually if you're pitching right onto a yeast cake oxygen isn't important since there probably won't be a lag or growth phase at all.

If you're saving the yeast in a jar or something and pitching a portion of it, certainly try to aerate.

[GuingesRock]

^ Listen to Rob. He's the yeast expert.

[GAM]

I do this time to time mostly to save on cleaning. The next clean up is a bit harder.

Put in in a tray as it often foams over.

Sandy

[spears104]

I've done this many times with great results. No lag and vigorous fermentation within a couple of hours.

[voltage]

This is really interesting to me. I have been using spare beer yeasts packets to make cider so I might have to try this trick. I will admit I have been sceptical so far but this thread is winning me over.

[jtmwhyte]

Whenever I'm planning a big beer (read: high original gravity) I like to make a session beer a few weeks before and pitch the big wort into the yeast cake

[dean2k]

Is it safe to assume the flavour of the new wort going in isn't going to be (overly) affected by the the flavour of any leftover trub? Just by virtue of sheer volume difference?

[CorneliusAlphonse]

It will have some influence, eg with a hoppy beer the sediment usually contains a lot of hop particles, which will affect the next beer (especially if you're doing something with low hop flavour)

[dean2k]

It will have some influence, eg with a hoppy beer the sediment usually contains a lot of hop particles, which will affect the next beer (especially if you're doing something with low hop flavour)

Hmm... that's exactly the case I'm worried about. Wonder if I could (carefully) give the yeast a preliminary wash to remove most of the trub and reuse it the same day without making a starter?

[Broob]

It will have some influence, eg with a hoppy beer the sediment usually contains a lot of hop particles, which will affect the next beer (especially if you're doing something with low hop flavour)

Hmm... that's exactly the case I'm worried about. Wonder if I could (carefully) give the yeast a preliminary wash to remove most of the trub and reuse it the same day without making a starter?

I plan on making a bohemian pilsner in the next little while and when that's done fermenting I was thinking about throwing a Schwarzbier right on top of the yeast cake or like you said washing the yeast/trub and using it the same day. Not sure which way is better but either way beats making a 4 L lager starter.

[CorneliusAlphonse]

I think most people go in increasing levels of flavour, eg brewing an APA then an IPA then a RIS.

Yeast washing/rinsing can definitely be used if you want to brew in a different order than that but you have to be super careful and confident of your sanitation. honestly the flavour carryover is probably pretty minimal but its something to consider

[DrinkNBrew]

Lots of great points here. Another thing you may want to consider is the effect on the shelf life - not a big deal if your drinking it pretty quick, but that trub (hop lipids, dead yeast cells, and whatnot) can really shorten the life of the beer. Also, the yeast cake would have way more yeast then you need and you won't get the growth phase and ester production - some esters are needed even in a lager. Yeast washing is probably always a good thing, it will clean up the garbage and also limit the cells you're pitching.