Why Didn’t I Start Reusing Yeast a Long Time Ago?

Yeast From Primary FermenterOne thing that has constantly surprised me about homebrewing is that once you peel back the mystery on a particular method or aspect of brewing, pretty much everything turns out to be pretty easy. Which is part of the reason it’s such a rewarding hobby.
My latest discovery is reusing homebrew yeast. I’ve known since I started homebrewing that people would reuse and even “wash” yeast cake, but after reading about it and watching videos, it seemed like a process, which was difficult and was prone to introducing infection.
In addition, when you have racked your fermenter into a bottling bucket or keg, let’s face it, the stuff that’s left over is pretty nasty.
Well, a few weeks ago, I realized I had quite a few partial bags of hop pellets leftover from previous brews, so I decided to make a “kitchen-sink” beer to use up as much of those as I could. As chance would have it, the ideal day for brewing that was the day after I was going to be bottling a different batch of beer in which had used US-05 yeast. So, I decided that as long as I wasn’t going to spend money on hops and this was a largely experimental beer, I might as well try reusing the yeast from the primary fermenter.
I had read about an experiment where the brewer had used a pint or so of the yeast slurry at the bottom of a primary fermenter, along with new homebrew yeast which had been made into a starter. He brewed a batch, and split it into two fermenters, pitching the different yeasts. To make a long story short, there wasn’t much noticeable difference in the finished beers.
Well, that was enough for me, so in this latest batch, I just grabbed a little over a pint of the yeast cake from the primary fermenter. I put it in a mason jar in the fridge over night. The next day I took it out of the fridge in the morning, and when ready to pitch, I decanted off the liquid on top and pitched the sludge into my experimental beer.
Shop Liquid Beer YeastThe reused homebrew yeast took off pretty fast, and within four hours, it was bubbling away in the airlock. A little faster starting, but otherwise really nothing different than usual. I will say I noticed a larger krausen ring than I normally see. I cleared with gelatin, bottled, and waited.
I’ve been drinking this batch for about a week now. It’s not a heavy beer, but was meant to be a lighter beer. Not hoppy, but very well balanced. Very enjoyable, and in fact, as much as I hate to admit, it’s a little better than the previous batch which is a beer I’ve brewed quite a few times.
I am very happy with my decision to reuse the homebrew yeast cake from the primary fermenter, and I would encourage everyone to give it a try.

Do you ever reuse homebrew yeast? Why or why not?
John Torrance is a database developer, gadget lover, and avid home brewer living in Lafayette, Colorado. When he’s not actively brewing, he’s generally daydreaming about what he’s going to brew for his next batch.

11 thoughts on “Why Didn’t I Start Reusing Yeast a Long Time Ago?

  1. Rather than reuse yeast and having to wash it, etc., I recommend making an initial starter much larger than what you need for the beer you are brewing, then only using a portion of it. Save the other portion to either make another beer or another yeast starter, which can be split again and again, as long as you are happy with that yeast…

  2. I’ve been seen articles on the subject of reusing yeast, never tried it, but I think I will on my next batch.

  3. I have reused yeast quite often. The easiest way is to time racking of a beer off the yeast and pour a similar beer onto the yeast left in the fermenter. I have been successful with this method using s04, us05, Nottingham, and one other I can not recall. I have also put yeast in ball jars and saved it for a week or so and had it work out very well.

  4. I almost never buy yeast.
    I’ve only been brewing for eight years. I do 10 gallon batches. I’m about to keg/bottle batch number 142. I only buy yeast if I really need a strain that I don’t have stored away in my cooler and I can’t get what I need from a local brewery. (Most local breweries are happy to share. They have nothing to gain by not sharing, since they throw many gallons of fresh yeast slurry away every year.)
    I’m just not about to spend the money for a packet or two of yeast every time I brew!
    However, I am fastidious about sterility of containers and procedures. I only store the yeast in containers that have been sanitized in boiling water. I use isopropyl alcohol every time I make transfers. (And keep in mind, when you use a sanitizer, it takes time to work; you can’t just spray some bleach or iodine or Starsan onto a surface and expect it to have killed contaminants unless you’ve waited a few minutes.)
    In any case, I use yeast that I first obtained and used 3 or 4 or 5 years ago, propagate it, and it seems to work just fine

    • I have not tried to keep a yeast strain going for that long, but I have gotten 6 to 8 beers from a single packet. I had one batch of Octoberfest get infected (very sour) and could not figure out how it happened so I have been very cautious with my sanitation ever since, and now probably buy more yeast then I need. I do have friends that use yeast for years with no problems.

  5. i brew cider for the guys at work yes we have cider on tap at work its a real cool company lol
    anyway i reuse the yeast at least twice if not 3 times and all i do is dump new apple juice (musselmans $4.5 gallon on jet dot com +free delivery) on top of the yeast cake and it takes off like a rocket so far i have not had any issues 2nd batch seams to finish a lot quicker about 4-5 days and its ready for 2ndary vs 6-7 days for first batch

  6. When the timing is right I always re-use yeast from the previous batch. I saved all the unused yeast packets and noted the type of yeast and date set aside. I’ve never had any bad experiences with re-using yeast.
    Any residual yeast from my fermentation tank goes to the chickens (they love beer dregs, too) and ducks for their nutrition value.

  7. My brew friend and I have been doing this for a little while now. It’s fun to try new things. Another one we do is drink a favorite 6pak of beer and save the yeast off the bottom of the bottles. A week before we brew we do a small yeast starter to build it up. About 2 cups of wort. Once that’s fermented a couple days then we bump it up to about half a gallon of wort and put it on the stir plate. That weekend when we brew we have billions of billions of yeast cells to throw in. Has been a rewarding hobby.
    Also dumping a wort/beer onto an existing yeast cake has worked the two times I have tried it. Make sure and put a bigger airlock on it! It goes like crazy!

Comments are closed.