Pitching onto a fresh yeast cake

[biggtime]

Guys, I'm planning a brew day tomorrow, and will also be racking off a brew from the fermenter so thought it would be a good time to contemplate pitching onto the yeast cake. Anyone want to talk me out of it?

One issue: the beer just completed fermenting is a 5.5% spicy Christmas ale, the beer brewed tomorrow will be 4% best bitter. Not ideal, I suppose. Too risky for the flavour profile?

Other question: seems from searching the forum that opinion varies on wisdom of pitching straight onto an uncleaned yeast cake in an uncleaned fermenter. If there were only a short gap between racking off and pitching the new beer, is it generally safe to simply pour it straight on? Or is it really much better to clean and split the yeast (and sterilise FV, of course)?

Cheers!

 

[dennisking]

The one time I did this it was not the best beer I've produced but that could be coincidence. All I have read about reusing yeast say's don't reuse in a lower gravity brew.

 

[Runwell-Steve]

I'm sure there are people who know better than me but I've done a very similar thing, pitched a light hoppy beer straight onto the yeast cake of a stout. I did this as I discovered I had no yeast so all I could do was reuse what I had. It turned out to be one of my best beers, it was a very fast ferment.

 

[pittsy]

I would def use a clean fv , and if poss wash yeast . Better to get some of the krausen on day 2 to 3 and make a starter with it , it'll be the healthiest most active yeast while the cake will be dead and poor yeast as well .

 

[anthonyUK]

...while the cake will be dead and poor yeast as well .

I agree except with the last part. I have read in numerous places that pitching on to a previous cake is in effect massively overpitching as there are too many viable cells.

If it is all you can do then it will work but as pittsy said it is better to crop and step up a starter so you at least have an idea of the number of cells you are pitching.

 

[graysalchemy]

I would definately use a fresh clean Fv as a matter of course. I have had good results some times too good. You will probably end up over pitching so I would use half a yeast cake. last time I did it I used a notty yeast cake from 55L bitter in 40L of 1070 elderberry stout and even in a 70L fermenter the yeast made a bid for freedom, well more than just a bid..........

 

[adomant]

Too late to top crop for this one (better idea for the future). I would definitely rinse out into a sterile pet bottle or tub with pre boiled or mineral water and, as you say, split the trub off the top and dead yeast cells off the bottom. It won't take long and you can decide how much to pitch.

 

[foxy]

Don't be put off trying it just make sure the higher gravity beer goes in second because there is a hell of a lot of yeast in there. It used to be common practice years ago.

 

[biggtime]

Thanks guys. Stronger beer already went in first - there's nothing I can do about that, I'm afraid. And most of you are making me pretty wary of trying this on this occasion. A further issue, there will be things like orange zest from the Christmas Beer mixed in the trub of the yeast cake. I wonder whether such a strong flavour risks coming through, even if I clean the yeast...

 

[Pjam]

I too was about to ask the same ........ My next question is - How does one wash the yeast?

 

[biggtime]

I too was about to ask the same ........ My next question is - How does one wash the yeast?

I'll attempt an answer, but others will know more/point out where I've got it wrong. Basically, I think you collect up plenty of the cake, put in a clean (sanitised?) glass jar with cooled boiled water, give it a good shake and let it settle out. As I understand it, you want the stuff that stays in suspension rather than the stuff that drops to the bottom.

Then store in sterilised sealed vessels in fridge, or pitch! At least, that's what I've understood so far...

 

[graysalchemy]

HAve a look herefor a good procedure.

 

[mike77]

I have brewed directly onto the old yeast cake before with no problem. Alternatively I have collected jam jars full of slurry kept them in the fridge and then pitched a jar straight into a new brew again with no problems.

 

[Pjam]

HAve a look herefor a good procedure.

That's excellent, thanks I'll give it a go.

 

[biggtime]

In the end, I bottled it, as it were. Didn't want to risk the spicy, orange zest flavours of the stronger beer affecting the weaker best bitter. But great to see the useful links on approaches. I'll try it when I am doing things in a better order (i.e. weaker beer first) and see how it goes. Thanks, as ever, for the advice.