Easy Yeast Washing
Posted Jul 18th 2013 | By:
After using a couple of different liquid yeasts for the first time, I decided that since they cost $6.50 a pop, that it'd be the most economical to wash the yeasts for re-use. And being retired, I can't afford to spend a whole lot on the needed equipment to do so. Enter Giant Eagle and BP. They both have Tostitos brand chip dips and salsas in those 15 some ounce jars on the chip shelves. The labels are plastic and easy to peel off. Wash them out in the sink, then soak in PBW for a little while. Rinse well and sanitize with Star San before storage for later use.
I feel that this helps prevent anything nasty from getting a foothold in the jars until they're actually used. I sanitize them again right before filling.I also found the 1 gallon size Vlasic kosher dills in a fancy looking glass jar on sale for $2.99 at Giant Eagle as well. Bingo, perfect size for yeast washing!I soaked it for about a week with PBW to get most of the pickle smell out of it. The little bit of smell left will come out with successive cleanings and sanitizings. So, using about 2C of the boiled and cooled water, pour it into the fermenter and swirl it around to loosen the compacted yeast and trub.
Pour this into the washing jar, and top off with boiled and cooled water until nearly full, or at least 3/4s of the way up. I try to tailor the total volume to how many jars I have available to fill, minus some 3-5 inches of trub that will invariably settle out. Three or four of these jars will be enough. In this first pic, you can also see the oz markings on either side of the logo.
In this pic, I'd already filled two jars and was waiting for more trub to settle out.It isn't a quick process. It took a couple hours to settle the trub about 1/2 of the way down to pour off a couple jars. Didn't think of doing this write-up until this point. So I had to wait for it to settle out some more. Here's a pic that shows the layering effect as the heavier trub settles out of the yeast and liquid.
You can wait until the trub settles some 2/3s of the way down, but time is a double-edged sword here. As the trub is settling down, so is the yeast in the liquid column above that. At the very top, you can see the liquid is starting to clear.
So you can't wait too long to pour off the yeast/liquid mixture. Keep an eye on the darker colored trub layer. It slowly follows the yeast to the top of the jar and you'll start pouring that if you're not observant. After pouring a jar full to just under the threads (just like when canning), you have to wait for the trub layer to settle down some more. Here's how far I fill the jars.
And waiting for it to settle out more...
I got part of a jar's worth, had to wait for it to settle down once again.
I used a notepad and fiber glass reinforced packing tape to make labels for the jars. Yeast type number and name, date collected (if not washed right away), date washed. After it's used once for a starter, the next batches label should denote that it's the 2nd washing, 3rd, etc. to keep track of how many times it's been washed and reused.
I initially had to save all the yeast until I got a jar big enough to wash in. So any more than 3 days or so in the fridge, the yeast when warmed will flake and clump. It'll then go to the bottom of the washing jar first. So it's best to have enough jars to wash it right after collecting from the primary fermenter. This way, you can let the trub layer settle 1/2 to 2/3s of the way down and start filling jars until the trub comes up to the top of the washing jar.
In these next two pics you can see two jars I had in the fridge from the bottom of the first batch of the same yeast. A substantial trub layer can be seen in the jar on the left.
In this next pic you can see where the yeast flaked and clumped up after being in the fridge about one month. I tried swirling it to break it up, but it didn't seem to wanna break up very easily.
This view also shows the aftermath of adding the jar with all the trub to the other jar after pouring off most of the clear liquid to make room for the addition. I had sanitized a pint glass to pour off the extra liquid in and covered with plastic wrap. I figured it'd be better used to top off the jars in case I came up a little short from washing the last jar or two.
I also made sure to re-wash and sanitize the now empty previous jar to pour off more yeast into. You can see that in this pic.
I wound up getting about 2/3s of that last jar out of the washing jar. You can't pour off liquid yeast all the way down to the compacted trub. You'll definitely lose a little yeast to the trub, which won't stay put as you drain off successive pourings. It basically lowers the level of yeast and liquid down closer to the trub in actual practice from my observations. So put them in the fridge for at least about 3 days to give them time to settle down well. The you can easily pour off about 3/4s of the clear liquid when making a starter. I use an 1000mL Erlenmeyer flask to make starters of 800-1000mL. Here's a pic of an 800mL starter I did with one batch of the WL029 yeast I used on my light and dark hybrid lagers.
This size starter would be a good average amount of wort to use with 1 jar of the washed/settled yeast. About 1/4C of plain extra light or light DME mixed in boiled water to 800-1000mL (1L) Stir til DME is comopletely dissolved. Cool in ice bath till down toabout 70F. Stir up yeast in warmed up jar & pour into flask with DME solution. Cover top loosely with sanitized aluminum foil to allow a little air in. but no nasties to settle in.Larger starters or successive starters for the same batch of yeast can be done to increase yield for fermenting bigger beers. I hope this write-up simplifies yeast washing somewhat. It isn't hard, but it will definitely take a considerable amount of time to finish. So wait until you're done with cleaning up after bottling day and sitting down with a homebrew or two with the rest of us to wash the yeast. It was a logical way to pass the time for me.
* I'll add some more pics to this posting when I wash the WL029 yeast to clarify the beginning of the process.
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