Yeast harvesting + vitality starter

One of the benefits of fermenting in a conical fermentor is the ease of yeast harvesting. I’m just starting to get into this. Up until now, I’ve used a different yeast strain for nearly every beer… and there’s not much point of harvesting yeast if you’re not going to end up using it again. So, an ongoing challenge of mine has been to refine the number of yeasts strains I use in my brewing. This is more difficult than I’d imagined, so, for now, I’m attempting to brew beers back to back that work well with the same strain. Most recently this has been a schwarzbier, followed by a helles, both using White Lab’s Southern German Lager strain – WLP838.

My process so far has been to perform a yeast dump into a sanitized 5L flask, then divide several litres of yeast slurry into sanitized pint jars. Eventually I’d like to incorporate an acid washing step, but I’m not there yet. Anyways, the pint jars full of slurry are sealed and placed at the back of the fridge until I’m ready to use them. I’d also like freeze (at least some of) my yeast instead of refrigerate for long term storage, but I’m also not quite there yet.

There’s a lot of yeast in these slurries; about 1 billion per millilitre of yeast cake. For me, this ends up being approximately 150 billion cells per pint jar. So as you can see it’s quite easy to harvest enough slurry such that a yeast starter isn’t necessary.

In refrigerated yeast cultures you can expect a loss in yeast cell viability and vitality. The loss of viability is irreversible, and estimated to be 25% per month. Vitality however is more dynamic and may be influenced through the environment of the yeast…

In walks the “vitality starter method”, brought to the attention to many of us homebrewers by the Brülosophy folks. It seems natural to utilize this method in combination with harvesting and storing yeast slurries to ensure a healthy, active fermentation. So… that’s what I’m experimenting with. It’s a bit early for me to comment on the effectiveness, however, I have found the process to be quite simple. I can prepare the vitality starter during the early stages of the boil without much trouble. 

 

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Step 1: Collect some early-into-the-boil wort, and quickly reboil in sanitized flask

 

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Step 2: Cool wort for vitality starter and decant supernatant from previously harvested yeast. Once wort is cooled, resuspend yeast and combine in flask.

 

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Step 3: Spin until pitching temperature reached (4-12 hours), then add to fermentor.

  8 comments for “Yeast harvesting + vitality starter

  1. Jon
    January 19, 2016 at 3:33 pm

    What is your chilling process. I love the idea of using the “early-in-the-boil” wort for the starter but I’m generally ready to pitch within an hour or two of flameout. Doesn’t leave the 4-12 hours you reference.

    • Justin
      January 19, 2016 at 3:57 pm

      I chill with a single pass through a counterflow chiller. During the summer this may leave my wort between 75-80F. My fermentation chamber (an all-fridge) is then tasked with bringing the wort temperature the rest of way down for pitching – around 65F for my ales and 50F for my lagers (exact temperature dependent on yeast strain and desired beer characteristics). I forget the exact rate in which my fermentation chamber is able to drop the temperature, I think it’s around 4F an hour for the 12 gallons or so that makes it into my fermentor. If I’m brewing a lager in the evening that may mean I don’t pitch until first thing the next morning.

      • Jon
        January 19, 2016 at 7:00 pm

        Got it. I use an immersion chiller in two stages with the second being pumping ice water through the coil to get to pitching temps. It might be worth skipping the second stage to use this process and avoid making a separate starter wort. I’m in AZ so I’m guessing I can only get in the high 80’s using tap water so I’ll need to test to see how long it would take. My fermentation fridge is a wine cooler which doesn’t chill as low as, for example a standard fridge or minifridge. Worth looking into! I enjoy the blog as I’m working to covert my controller for Strangebrew Elsinore. Keep up the good work!

        • Justin
          January 19, 2016 at 7:23 pm

          Thanks Jon! There’s a subscribe page accessible from the top if you’re interested in being notified of new posts – generally a couple times a month.

          I’d say as long as your sanitation practices are solid, you shouldn’t have a problem pitching within 24 hours. Mainly you’ll just want to be sure that stage one of your chilling procedure is fast and cold enough to get a good cold break (to prevent chill haze). Halting the production of DMS and stopping the isomerization of alpha acid are also important but it doesn’t take much to get below those temperatures.

          You’ll also want to consider temperature if you’re oxygenating your wort. Oxygen dissolves less readily in warm liquids. Perhaps wait until you’ve reached pitching temperatures to oxygenate if you’re going this route.

          Let me know if you have any questions about getting SBE running – either email, or over on reddit.com/r/strangebrew. Would love to see some pictures when you’re done.

          • Jon
            January 20, 2016 at 12:01 pm

            Definitely plan to post my setup to HBT when done. I’ve tested SBE (current version, not the Beta) on a test bed and it seems to work great. Worried that I’ll need a darlington array to power multiple SSR’s but my current setup is a recirculating eBIAB so and it seems like others are having success without it. I tried to subscribe but I got an error message when accessing the subscribe page. Here’s the message: [jetpack_subscription_form title=”” subscribe_text=””]

          • Justin
            January 20, 2016 at 12:05 pm

            Thanks for the heads up on that error. I wonder how long it’s been like that.

            The beta will be merged to master very soon I believe, changes are basically down to minor UI clean up. I’ve been using/testing it for awhile now. It’s quite the improvement.

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