# Recycling Yeast Cake



## Budgie_Smuggling (2/8/18)

Hi All,

I've been having a read and a search but can't find the exact answer I'm looking for. 

I've made the most of my days off brewing an AG IPA (1.060 OG) pitched with 2 x San Diego Super Yeast. I also brewed a similar IPA (similar recipe, hops, and OG) and no chilled it with a view to fermenting as soon as I get the first IPA out of the fermenter. 

My plan is to bottle brew 1, clear half of the slurry out and pitch the cube (brew 2) straight on top of the remaining yeast cake, give it a good shake for aeration, and airlock it. 

The other plan would be to sanitise a jar in boiling water and starsan, scoop half the cake into that, seal, clean and sanitise the fermenter and pitch as usual.

Any suggestions as to which would be the best/safest plan?

Thanks in advance!

Dan


----------



## hoppy2B (2/8/18)

Best practice is to take some yeast from the bottom of the fermenter and wash it, or so I'm led to believe. That should prevent any off flavours from carrying over.

I even go to the trouble of washing starters sometime. I like to do it for starters made from smack packs.


----------



## shacked (3/8/18)

I'd go with option 2 mate. A cup or 2 of slurry and you'll be sweet; or you can use this calculator: http://www.mrmalty.com/calc/calc.html 

Washing is good but also exposes you to more opportunities to introduce unwanted nasties.


----------



## EalingDrop (3/8/18)

Is there anyway of knowing if its absolutely pure? One assumes going through the various stages of Pitch, Ferment to packaging, that its free of contaminates. 

I've harvested yeast and repitched for a while, but I still think about the purity of the yeast slurry every time prior to pitch.

Does anyone have any other ways of testing for purity apart from the old smell and taste the yeast starter?


----------



## hoppy2B (3/8/18)

EalingDrop said:


> Is there anyway of knowing if its absolutely pure?




You could put it under a microscope. But then how much of the yeast slurry do you need to look at to know if it is pure? So it really comes down to your definition of "purity". It's probably not a good idea to pitch the slurry from something that has been dry hopped, especially if the dry hop was done with whole cones.

I don't use the yeast cake from a brew because there are so many different yeast strains out there to try, and so many different styles of beer to make. If I do reuse yeast it is usually from a bottle that I made a year or two ago. If it hasn't gone flat, become a gusher, or developed an off flavour, then I figure it is good to go. 

If you do want to dry hop and reuse yeast, transfer and dry hop in secondary and save some yeast from primary. As long as you know what you are doing, and you have a good process, you shouldn't have a problem.


----------



## Topher (4/9/18)

Option 2 works. It's a bit risky but it has worked for this time poor brewer.
Just watch out, either way....pitching with the cake will take off quicker and it's easy to get a slightly more vigorous ferment than you expect.......

This was about 1/3 of the cake, repitching with a similar beer. Ferment temp 18c Nottingham is such a beast.


----------



## Thomas Wood (5/9/18)

I'm about to start recycling my yeast cake as the plain dry yeast packets aren't quite cutting it for me and I finally bought some US-05. If I fill up a mason jar with yeast, I can get ~3 pitches out of that right?
Can I then fill up a mason jar with each successive brew and use that? Essentially having unlimited yeast for a couple of brews?

I'm not too interested in washing or making a starter, so whats the time limit I can store a mason jar in the fridge with the cake? I've seen 2 months mentioned a bit.

So I guess can I recycle yeast cake 1. Get 3 brews from it, recycle one of those yeast cakes, get 3 more brews, before I then get another dry packet?


----------



## Leyther (5/9/18)

Thomas Wood said:


> I'm about to start recycling my yeast cake as the plain dry yeast packets aren't quite cutting it for me and I finally bought some US-05. If I fill up a mason jar with yeast, I can get ~3 pitches out of that right?
> Can I then fill up a mason jar with each successive brew and use that? Essentially having unlimited yeast for a couple of brews?
> 
> I'm not too interested in washing or making a starter, so whats the time limit I can store a mason jar in the fridge with the cake? I've seen 2 months mentioned a bit.
> ...



Yes you can do this, I have done it but only when I am repitching within a couple of weeks, keep it in the fridge in the meantime. I don't do an acid wash but I do add cooled boiled water and mix and let it settle then pour off the water and try capture just the yeast, if its come from a dry hopped beer the yeast usually sits below the water and above the hops as the nice creamy layer.

The other thing to do is ensure you try the beer its come from first!!! If its crap your wasting two batches!!! 

Also make sure your pitching into something similar.


----------



## Rocker1986 (5/9/18)

It would probably do your viability and consistency better to simply harvest from each batch and repitch to the next rather than take enough for three batches at once. The third one is gonna end up being pitched with less yeast than the second, which will get less yeast than the first, unless you're pitching all three at once. 

I did get into the whole starters thing myself, and began using them as a harvesting method as well. I hardly ever buy yeast anymore, they run up to about 15 generations before I replace them x 3 strains gets me about 2 years worth of brewing from three smack packs.


----------



## Thomas Wood (5/9/18)

Rocker1986 said:


> It would probably do your viability and consistency better to simply harvest from each batch and repitch to the next rather than take enough for three batches at once


Fair point, I was just unsure if that could work. Seems like the right way to go since I nearly always keg and brew on the same day.


----------



## koshari (5/9/18)

Thomas Wood said:


> Fair point, I was just unsure if that could work. Seems like the right way to go since I nearly always keg and brew on the same day.


you can still place it a a sterile jar in the frige between brews, dont have to be literally back to back.


----------



## shacked (6/9/18)

Worth a read: https://www.whitelabs.com/beer/yeast-storage-and-maintenance-0


----------



## Rocker1986 (6/9/18)

I store mine under beer in the fridge. Well, unhopped beer. I make starters bigger than necessary and take the excess into a jar and store it. Often it's stored up to two months before being pitched into another starter where the process repeats. Seems to work fine if the beer is any indication. 
Did a bit of viability testing last year and found it much higher than 50% after four weeks (closer to 90% if I remember rightly), however slurry from an actual batch may drop faster. Planning some tests on that too.


----------



## Thomas Wood (6/9/18)

Lots of good information here. I'm about 2 weeks away from needing to recycle my yeast cake. But just to get the basic instructions broken down:

Add some water to fermenter and shake around the trub
Collect it into a couple of clean mason jars (or a soft drink bottle, etc)
Chuck it in the fridge
When I am ready to brew next (generally that arvo), grab out a jar
Pour off the top layer (1cm or all the watery bit?) down the drain
Pitch the rest in, or at least 100-200ml (whatever the calculation ends up as from http://www.mrmalty.com/calc/calc.html) of the creamy looking stuff
Is that about right?


----------



## Abird89 (6/9/18)

Thomas Wood said:


> Lots of good information here. I'm about 2 weeks away from needing to recycle my yeast cake. But just to get the basic instructions broken down:
> 
> Add some water to fermenter and shake around the trub
> Collect it into a couple of clean mason jars (or a soft drink bottle, etc)
> ...



Step 1 - make sure it's water that's been boiled adequately first. Then when it cools throw in


----------



## Rocker1986 (6/9/18)

If you're repitching the same day you might as well just leave the yeast out of the fridge. Not much point putting it in there for a few hours. If storing for longer, then yes in the fridge is best.

If you're repitching into a similar batch you could just scoop out about a third of the cake into a jar with a bit of pre-boiled cooled water, rather than putting the water in the fermenter, then swirl it all up and pitch when the time comes.


----------



## shacked (6/9/18)

Thomas Wood said:


> Lots of good information here. I'm about 2 weeks away from needing to recycle my yeast cake. But just to get the basic instructions broken down:
> 
> Add some water to fermenter and shake around the trub
> Collect it into a couple of clean mason jars (or a soft drink bottle, etc)
> ...



Just leave a little beer in the bottom of the fermenter, swirl up, put in container, put in fridge, put in beer (all of it), repeat. 

Be advised, there will be some Co2 in the mix so don't put the lid on your container too tight at the start.


----------



## Thomas Wood (6/9/18)

Great, thanks for all your help guys


----------



## Tony M (7/9/18)

Just a pointer here. I've harvested yeast for many a year, but until I started pressure cooking my containers and ladle, I had quite a few dodgy brews. I save two 100ml bottles and pitch one into a 50L batch if it's fresh. If it's been sleeping in the fridge for months, I'll make a starter so that I'm not nervously waiting a couple of days for some activity.


----------



## altone (7/9/18)

Tony M said:


> Just a pointer here. I've harvested yeast for many a year, but until I started pressure cooking my containers and ladle, I had quite a few dodgy brews. I save two 100ml bottles and pitch one into a 50L batch if it's fresh. If it's been sleeping in the fridge for months, I'll make a starter so that I'm not nervously waiting a couple of days for some activity.



Good point! I do the oven method for sterilization - 15 mins at 120c and use empty pasta sauce etc. jars.
I only use them once as the seals start to break down if you put them in the oven a second time.


----------



## Rocker1986 (7/9/18)

I just stick mine in mason jars soaked in perc, rinsed and sprayed with starsan, never had a problem so far.


----------



## koshari (8/9/18)

shacked said:


> Just leave a little beer in the bottom of the fermenter, swirl up, put in container, put in fridge, put in beer (all of it), repeat.
> 
> Be advised, there will be some Co2 in the mix so don't put the lid on your container too tight at the start.


Thats more or less what i do.


----------

