Harvesting Yeast from commercial bottles
Posted Feb 09th 2012 | By:
I've been posting about this topic a lot lately, it seems that many brewers want to harvest yeast from some of their favorite commercial breweries. some really good craft breweries bottle condition a few of their brews with what seems like a gift to us home brewers. Rogue and Bell's are the two that immediately come into my mind when it comes to an easy harvest. for this blog, i'll be demonstrating how to harvest yeast from 4 bottles of Bell's Amber Ale. my wife and i both love Bell's beer, quite a few of their offerings are regulars in our home.
First off, you'll want to get yourself a 6 pack of the beer you'll be harvesting from. make sure you know the beer has enough viable yeast, and that it's the strain you seek. many breweries bottle with a strain other than the fermentation strain. i know the Bell's Amber has lots of good yeast, and i've had alotta luck harvesting from 3 or 4 bottles of dregs. now, you wanna drink some beer, but make sure you're careful and sanitary while pouring your beer, and recap immediately with a sanitized cap.
That's about what ya need to drink beer if you're saving the yeast. make sure everything's sanitized. notice the handy dandy Home Cheapo spray bottle of star san. i can't stress enough how awesome that is to have around, you can sanitize everything. even your hands and the glass. after opening the beer, flame the lip of the bottle, cap and refrigerate. repeat this with 3 or more bottles, which is one of my favorite parts about harvesting yeast.
when i pour the beer, i like to use a twelve oz glass and give it a decent pour down the middle, as to pour a good head and it'll pretty much force you to leave ~1 oz of beer behind with the yeast. i often leave more behind, but no biggie, this first starter is really to wake these guys up and get them ready to make a whole new generation of yeast. these cheap 12 oz glasses from Midwest are great, and they kinda look nice. i drink most of my bottle conditioned beers from these. i think they charge like $1-2 if you buy one with an ingredient kit, and they often throw them in for free when i make a big purchase there. probably an in store thing, Midwest is pretty much my LHBS.
back to the point here, when you're ready to make the first starter, you'll need some extra light DME. i used 14g to make ~200 ml of wort, figuring in the liquid in the bottles, that'll give me an OG of ~1.02, give or take.
since this was such a small amount of DME, i weighed it in the measuring cup, and added boiling water that i'd preboiled in my flask to ~200ml. i let the wort sit for a several minutes until all the DME is dissolved and then i spray it with star san and put it in the fridge until it's ~70 degrees.
while it's cooling, i sanitize an area of my table, get the bottles, an opener, and my flask sanitized and it place for pitching.
make sure everything's nice and sanitized, and when your wort's ~70, pour it in the flask and shake the $h!t out of it to aerate. use a sanitized opener to open each bottle after giving each one a little swirl to rouse the yeast. pour them in, flame the lip of the flask, cover with sanitized foil and shake some more.
i obviously had more liquid in the bottles than i planned on, but again, no biggie. a glass of my Simarillo Pale Ale helped me RDW here. the point here is to give the yeast a low gravity solution of maltose to wake up the survivors. those will be the strong yeast, the ones worthy of repopulating the earth (your beer). i expect this little starter to take a day or so to kick off, and i don't expect to see a lot of activity like i would in a brewing starter. i use the intermittent shake method, and shake as i would any other starter until it's fully fermented. then i cold crash for a day or two.
the next step will be to decant the first starter as best you can and create 500 ml of ~1.02 wort. that's 25 g of extra light DME, and add water up to ~500 ml. boil, add nutrient and chill to pitching temps, ~70 degrees. when the wort is cool, pour it into the flask of yeast slurry and shake like you've never shook before. remember, be strict in your sanitation every step of the way, you want the purest yeast population possible. sanitize and resanitize everything.
when this starter's done, repeat the process of cold crashing and decanting the starter beer. now the yeast are ready to start building you a population of yeast worthy of your next brew. this time, make 500 ml of normal starter wort, ~1.04. ferment this out and pitch slurry into a 1 L starter, finally, you now have a good population of yeast and this starter should look and act like the ones you make from a smack pack or vial.
now you can plan your next brew, get all your numbers in order, or your recipe kits ordered and in the mail. when the 1 L starter is finished, cold crash, decant and pitch the slurry into a starter according to MrMalty or another pitch rate calc. what i do with MrM in this case is see how large a starter i would need with one week old pack of yeast, i then make my starter accordingly.
you can also take the slurry from the 1L starter, and save it in mason jars, which is what i'll be doing with this harvest. the jars can be stored in the fridge for some time and used to make a starter for future brews.
this is a great way to acquire and save brewing yeast from your favorite brewery. like i said before, make sure you know that the brewery conditions with the fermentation strain. usually it's easy to find out with a quick search here on HBT or on google. i've also had some luck emailing the brewery with my plans and questions. in fact, the last time i communicated with a brewery about the yeast in their bottles, i got myself a nice (and free) Sweetgrass APA t-shirt from a friendly rep at Grand Teton. :rocking: when i asked a brewer at Boulevard if the yeast in their Wheat was the fermentation strain, he said it wasn't, but to try it in a pale ale and it should make a nice beer. i've found many pro brewers to be just like us home brewers, willing to share some info and ideas with a fellow craftsman.
i hope this is been helpful for those wanting to find out what the yeast from their favorite commercial brew does to their home brew. remember, the step up is a slow process, 2 weeks if you're on top of it. so be sure to RDW each and every day, and in good time you'll have enough healthy yeast to brew some beer.
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