Friday, June 15, 2007

Yeast from a bottle

In comments to a recent post on my plans for doing partial mash brewing, a-non-y-mous and Joe wanted to know how I recover yeast from bottles of beer.

Well, it's quite easy actually.

I first make a typical yeast starter. I usually boil about 1/4 to 1/2 cup of dry malt extract in about a quart of water. After cooling, I add it to a sanitized half-gallon bottle and affix a sanitized airlock.

Here comes the really hard part. I drink a bottle of beer made from the yeast I want to reculture. OK, that's a lie. I usually drink 2 beers. No, that's a lie too. Typically, I drink 4 of them. The truth is, the yeast from one bottle is enough to reculture, but why not give it a head start. Beside, the beer is good.

I pour out 10 ounces of the beer into a glass (and drink) and sanitize the neck and lip of the bottle. I swirl the remains of the beer and simply dump the yeast slurry into my starter. I repeat for any subsequent beers.

That's it. If fermentation starts and bubbles form by the next day, you are in business. Proceed as usual.

Sometimes you can refrigerate the yeast for use at a later date.

The beauty of this procedure is that it saves about $5 per batch. That can be about 15-20% of the cost for a batch.

I have 5 batches planned for the next month. Of those 5, I only needed to buy one yeast strain (Wyeast 1968 London ESB Ale yeast for a bitter I want to make). The most common strain I reculture is good ol' Wyeast 1056. I only reculture for 4-5 generations. After that I start with fresh yeast. Though, I've never noticed a difference between the fresh and recultured yeast.

6 comments:

chemist said...

if you go beyond 5 generations of yeast, what happens? Does the taste change?

A-non-y-mous said...

Thanks! I figured it was as easy as this, but I've never known of anyone actually doing this and having it work.

I use a conical fermenter, so I use the same yeast for 4 consecutive batches. So what I'd like to do is culture yeast from the bottle of the first batch, and use that for the following 4 batches (5-8). Call me cheap, but like you said, it'll save me an additional $6-7, every 4 batches.

Chemgeek said...

Collecting it from you primary fermentation is a MUCH better idea. The yeast in the bottles may not be identical to the original strain. I've never noticed a difference after 1 or 2 reuses, but I wouldn't push it. The yeast in the primary, from what I understand, is a better source.

BTW, you keep making me lust after conical fermenters every time you mention it. It is on my wish list, but still rather low on the list.

A-non-y-mous said...

The conical fermenter is the single best thing I've ever purchased for homebrewing (well, the immersion chiller is right up there, but it probably qualifies as an essential).

Just sanitize, pour in the brew, add yeast, and let it ferment. Once fermentation is done, instead of racking it, you just open the lower ball valve and remove the sludge (mainly yeast and hops/grain dust). I'll do this every few days, which is akin to racking to a secondary several times.

Then pour in the priming sugar, bottle from the side ball valve. While bottling you have another batch boiling away. When done, just toss it in the fermenter, there's already about 2 quarts of yeast in there. No sanitization. Fermentation starts in about 5 minutes and is often done in ~24-36 hours. I'll do 4 batches in a row like this. By then I usually change yeast strains (4 batches American ales, then 4 batches british ales, etc.)

The real advantages, for me, is a clearer beer, and the time and cost savings. Time wise there's no racking to a secondary, and no sanitization (except for the first time). Cost wise I save ~$7 plus S&H (no local beer store).

Another thing that may sound odd at first: it's not air-tight. The lid sits loose on top. With all of the CO2 produced, there's positive pressure coming out of the fementer, so bacteria can't get in. After ~100 batches I've never had a problem.

Anyways, I use the 8 gallon fermenter from http://www.minibrew.com/
The price was much cheaper 5 years ago!

I'm not trying to be a salesman, I just want to pass on something that makes my brewing experience 10x better/easier.

joe said...

Thanks for the info! I'll have to look into giving this a shot next time around.

Papa said...

Thank for the info Chem! I haven't tried it myself, but would it be possible (and more practicle) to just partition off (say maybe 4 batches) the original packet of Wyeast? And would it be the same process? Could you just cap a pint/liter bottle or is there another reason of using an airlock? Just like you, I'm trying to save my nickles for more grain and hops.... I figured if I just propagated directly from the smack pack, I'd save myself an incredible amount of $ and since I double batch (10 gal batches), I would also like to experiment with the different strains on the same boil. Just wondering how you would go about this... Thanks!