Re-using yeast - how?

Donoroto

Donoroto

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I'm a day away from kegging an ale brewed with S 04, and ready to brew a different recipe that also happens to use S 04. Tell me about taking some of the yeast from the bottom of the fermenter and using it to pitch the new brew.

Do I just scoop up a couple of tablespoons, or all of it? About how much is there? I am guessing well in excess of 200 B cells, and I need to use a small dixie cup full (3 ounces, about 90 ml).

I've heard about 'washing' the yeast: What's that mean, and how is it done?

The previous brew was dry-hopped, so should I try to separate yeast from hops glop? How?

I mean, I can just go buy 2 packs of S 04, about $6 total, but if I can re-use the yeast I have, well, that's progress, learning something new, and saving a buck all at once!
 
Bubba Wade said:
A lot of people reuse yeast, but I have always gone with fresh yeast. It's cheap, pretty much foolproof, and one less thing to go wrong.
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This is where I am. When I was doing extract batches I was thinking about harvesting yeast cause I was looking for anyway to drive down my costs. The answer though was just going to BIAB so I'm not spending like $50 or more per brew. Now that I get like 3 brews for that same money there's no reason to chance things with the yeast. Yeast is cheap enough, especially dry, I'm fine using a fresh satchet every time
 
I am a BIAB brewer, who brews small batch ales with US-05 dry yeast. In my 1.5 gallon batches where I have used new yeast, I have pitched a whole packet of yeast. Several times, I have reused yeast, saving the cost of another packet. A few times, I have put new beer on a yeast cake from a previous brew. Other times, I have pitched harvested yeast from a Mason jar. Overall, my results have been acceptable.
 
I use a fresh pack for a beer then pour the yeast from the fermenter in a sanitized jar. Then using the calculator in the recipe builder I scoop what I need. I do small batches so I use half a pack for the initial use then I get another 3 batches. So a pack gets me 8 batches. If you are fermenting a beer using the same yeast on the same day then you are in real good shape. It’s already warm and ready to work like a starter. I don’t wash or anything
 
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One common approach for capturing the yeast is to build a starter before you brew that's larger than you need. You then keep the excess starter in the fridge and then use it for the starter for the next batch. The other main approach is once you've got most of the beer out of the fermenter you swirl up all the sediment and the small amount of beer and then add that to a container that you keep in the fridge and use for the next batch. I use PET bottles to store the slurry, that way I can open the lid a crack every couple of weeks in case there's some residual fermentation and stops any chance of the bottle exploding.

There's no need to wash the yeast with the first approach. Some people wash the yeast slurry when using the second approach. They're worried about hop and beer residue from the first batch changing the taste of the next beer you brew. I've used the second approach a number of times and, personally, I don't see the point of washing the slurry. If I capture a slurry from a black IPA I won't use it in a pale lager, but other than those obvious combinations, I just don't see the slurries as having enough flavour to change the second beer, especially when compared to the risks of infection and storing the yeast under water that come with washing.

If you want to try the washing there's a few youtube videos that will be better than any explanation I can do.

If you've captured the slurry and you're ready for the next batch use the slurry option in the pitching rate calculator here to come up with an idea of how much slurry to pitch. If it's been in the fridge for more than six weeks between batches you would be better off making up a starter rather than just pitching the slurry.

If I'm pitching slurry I'll capture 500 ml of wort at the end of the mash, cool it down and pitch the slurry and a bit of yeast nutrient into that and shake it as hard as I can. Then by the time the beer has cooled it should be showing signs of activity and I'm pretty confident it will ferment out the batch. If there's no activity it might be time to crack open the emergency dried yeast you keep for emergencies.
 
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Mark Farrall said:
The other main approach is once you've got most of the beer out of the fermenter you swirl up all the sediment and the small amount of beer and then add that to a container that you keep in the fridge and use for the next batch.
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Plus one there Mate!

There's a recent thread on this board about washing or slurry...I'll look later and link....I did a batch of stout with Kveik slurry last month and have a couple of mason jars in the fridge from this method waiting reuse; one from the original batch of brown and the second generation used in the stout. I plan on using the slurry from the blonde that I have fermenting right now in the same way for some more blonde or amber ale.
 
here it is...and there's a lot of other ones...just search "slurry" with the tool and narrow it down with other key words. I totally admit to being a little intimidated at first with all the potential sanitary and contamination problems but this method makes it easy and washing a hassle. I'm sure washing has its advantage but this solution works for me!

Saving yeast slurry | Make Beer at Home Forums | Brewer's Friend
 
I follow M. Farrall method. I just stirr up the left overs after transfering out of the fermenter and store in a clean small Mason jar. Using 05. I usually just pitch the whole jar 8 oz. into the new batch. I have used the same yeast up to seven times with perfect results. Yes , I have seen the lid swell from a bit more fermenting left over. And if you loosen the lid when you get ready to brew your next batch some will crawl out of the jar as it warms up to room temp.
 
Mark Farrall said:
One common approach for capturing the yeast is to build a starter before you brew that's larger than you need. You then keep the excess starter in the fridge and then use it for the starter for the next batch.
Click to expand...

This is what I do. Easy to do and avoids the anxiety of potential problems of reusing the slurry from a previous brew. I may do that some day, like when I need a ton of yeast when brewing a high gravity beer.
 
Same as Bob, just leave the lid a bit loose and it will offgas itself. I did that once with a Saison yeast though, foamed all over everything.

I don't use slurry most of the time, I overbuild a starter but when I do a slurry I just get a 500ml mason jar and fill it 90% full and then wipe the outside down from the mess I made before putting a lid on it and putting it in the freezer.

It's not my preferred method but it works fine.
 
Thank you, thank you, thank you. I collected the slurry and, as I was re-reading this post and getting ready to post the photo, I was reminded that the lid needs to be LOOSE. I had it tight, and the jar top was already bulging out when I went to loosen it.

Crisis averted.

So I have over 600 mL of slurry, I only need about 200, and I also bought a package of yeast just to be safe. I'll let you know what happens in a couple of days.
 

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after a day or so in the fridge it will separate out and you'll see how much material you have. That should be plenty though.
 
Well, I scooped up the thick sludge instead of mixing it with the remaining beer, so when I pitch I plan to add some (boiled and cooled) water to make it more manageable. Not much separated out, but I am not concerned.
 
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