Reusing Yeast...

[ClownPrince]

I have designs on making a Marmalade IPA next weekend.
I'm currently fermenting a Pink Grapefruit IPA which is due to move to a secondary fermentor next weekend.
I've seen videos on Youtube where they drop the fresh Wort straight onto the slurry from a previous beer.
Is their any trick to this or do i just empty as much of the Grapefruit IPA out as possible and then pour straight onto the slurry?
Or should I just pop to Wilko and buy a pack of Gervin yeast?

 

[Loco_ola]

From what I've read you're best off washing some of the yeast rather than just throwing your wort on top of the existing trub. There's waste products and dead yeast in there.

http://beersmith.com/blog/2008/07/25/yeast-washing-reusing-your-yeast/

 

[samale]

I have designs on making a Marmalade IPA next weekend.
I'm currently fermenting a Pink Grapefruit IPA which is due to move to a secondary fermentor next weekend.
I've seen videos on Youtube where they drop the fresh Wort straight onto the slurry from a previous beer.
Is their any trick to this or do i just empty as much of the Grapefruit IPA out as possible and then pour straight onto the slurry?
Or should I just pop to Wilko and buy a pack of Gervin yeast?

I reuse my yeast alot. I just put it straight on top of the previous yeast cake

 

[Cwrw666]

Works ok if you do it once, but if you try it again ie. get 3 brews off one yeast cake, you'll notice the third brew is definitely worse than the first 2. Have done this a few times in the past when I've needed to get a lot of beer done quickly.

So... if you want 3 brews out of 1 packet of yeast, do the first brew as normal then put a few spoonfulls of the yeast cake in a sanitised jar. Use half for the next brew and the other half for the brew after that. Because you're only using a bit of the yeast cake, you're only adding a small proportion of the dead stuff into the next brews.

 

[terrym]

+1 on all @Cwrw666 has said.
I keep my yeast cake sealed up in the fridge, but rarely keep it for longer than a week before re-using it.

 

[ClownPrince]

Works ok if you do it once, but if you try it again ie. get 3 brews off one yeast cake, you'll notice the third brew is definitely worse than the first 2. Have done this a few times in the past when I've needed to get a lot of beer done quickly.

So... if you want 3 brews out of 1 packet of yeast, do the first brew as normal then put a few spoonfulls of the yeast cake in a sanitised jar. Use half for the next brew and the other half for the brew after that. Because you're only using a bit of the yeast cake, you're only adding a small proportion of the dead stuff into the next brews.

I only intend to reuse the yeast once, I mostly do kit brewing, so I mostly have fresh yeast available

+1 on all @Cwrw666 has said.
I keep my yeast cake sealed up in the fridge, but rarely keep it for longer than a week before re-using it.

It'll be the same day or at a push the day after.

Thank you all for the advice.

 

[An Ankoù]

Works ok if you do it once, but if you try it again ie. get 3 brews off one yeast cake, you'll notice the third brew is definitely worse than the first 2. Have done this a few times in the past when I've needed to get a lot of beer done quickly.

So... if you want 3 brews out of 1 packet of yeast, do the first brew as normal then put a few spoonfulls of the yeast cake in a sanitised jar. Use half for the next brew and the other half for the brew after that. Because you're only using a bit of the yeast cake, you're only adding a small proportion of the dead stuff into the next brews.

I've never been one for using yeast cake, preferring to top-harvest. Force of habit, I suppose, but recently I found that my cropped yeast was getting on for a month old so decided to use some of the slurry from the FV. I haven't found it's any worse than the top-cropped yeast. Yes it contains dead cells, but they'll provide nutrient for the next generation of yeast. I was more worried about break material and hop detritus degrading to provide off-flavours, but as I only use about an eighth of the cake and fermentation these days is at less than 16C, I don't suppose it contributes much of those. Yeasts used have been US-05 and W-34/70.

 

[MyQul]

What can happen, if you simply put the wort onto the whole yeast cake is you can get over attenuation because there's so much yeast to do the work. I've re-used slurry loads of time (because it's so easy). But I always pour as much of the yeast cake into a jar as will fit. Then pour some of the slurry into the wort (dont ask me how much as I just eye ball it based on experience, which itself has come from trial and error)

 

[matt76]

I've done it a few times just reusing the whole yeast cake, worked out fine.

I asked on here recently about this, if I should re-use less than the whole yeast cake but the answer was generally keep it simple and chuck the fresh wort onto the whole cake.

There was a recent Experimental Brewing podcast where Denny Conn was saying he got best results from only using 1/3 of the yeast cake - and by "best" he said that was simply the beer he preferred, but didn't especially caution against reusing all of it.

 

[dwhite60]

Saturday I pitched about 250ml of slurry from a beer I brewed in November. It looks like this is done now actually, that or it's stuck. Never have had a stuck fermentation, ever.

I do this often without any issues. If the slurry smells good it's most likely fine.

All the Best,
D. White

 

[Drunkula]

I heard plenty about it not being optimum to use the whole thing. One is that some yeasts create the esters you want during the multiplication phase, with a whole cake they don't need to multiply.

And because you end up with a load of old-timers brewing the beer they can sometimes shart.

 

[lancon]

What can happen, if you simply put the wort onto the whole yeast cake is you can get over attenuation because there's so much yeast to do the work. I've re-used slurry loads of time (because it's so easy). But I always pour as much of the yeast cake into a jar as will fit. Then pour some of the slurry into the wort (dont ask me how much as I just eye ball it based on experience, which itself has come from trial and error)

I've done it a few times just reusing the whole yeast cake, worked out fine.

I asked on here recently about this, if I should re-use less than the whole yeast cake but the answer was generally keep it simple and chuck the fresh wort onto the whole cake.

There was a recent Experimental Brewing podcast where Denny Conn was saying he got best results from only using 1/3 of the yeast cake - and by "best" he said that was simply the beer he preferred, but didn't especially caution against reusing all of it.

I split the original into three, I think it is still over pitching and subsequently FG considerably lower than paperwork suggests 1.012 > 1.006. I also reuse it for up to 6 times, I read somewhere that 8 is maximum that it should be reused.

 

[MyQul]

I split the original into three, I think it is still over pitching and subsequently FG considerably lower than paperwork suggests 1.012 > 1.006. I also reuse it for up to 6 times, I read somewhere that 8 is maximum that it should be reused.

Yes, I'v read 6-8 repitches too. The way I (sometimes)do it, depending how big the jar/batch size is you can get 10-20 or more batches as your not repitching, just using the same generation to make starters with. So great if you dont want to spend money on liquid yeasts

 

[An Ankoù]

I tend to make 2 brews a week when I can, maybe only a couple of 12-litre batches with the weather being what it is. Nevertheless, I throw away more flasks of yeast than I use as I like to have a change and try other yeasts. My regulars that I use all the time are US-05 and W-34/70, but I tend to start a new sachet of these after a max of three generations. M42 keeps well, too, but I don't want to use it all that often and I can always start up a new batch from the dregs in a bottle of beer. I bought a lucky dip of 5 yeasts for a tenner from BrewUK last summer and I've only used one of them. I really must try out Lithuanian Farmhouse and other obscure varieties.

 

[Mrhandsome]

I've only been brewing since about June and I've so far only managed to use two packs of yeast. I either just dump the next batch on top of the yeast cake or I save a 500ml bottle of slurry to keep in the fridge for later use.

So far each beer I've made has been better than the last (which is probably more down to my process). I only throw out my yeast if I've done a high gravity beer because I read that it stresses it out.

 

[ClownPrince]

Thought I'd provide an update on this.
Everything went well enough with this. Had a bit of difficulty decanting the yeast, I wasn't expecting it to be as liquid as it was, I still managed to save about 1/5 of a 454g jar's worth though.
That all went into the new brew, which went off like a rocket after about 12 hours (luckily I had a blow off tube in place otherwise I would have had a messy kitchen) so I don't think i've done anything too wrong.
As per the advice on here, i won't try for a third brew with this yeast, but it's a good trick to know.
Thank you everyone.