harvest yeast from bottle?

I am drinking a Commercial Belgian White that comes with a bit of yeast settled in the bottom looking very much like any home brew I've ever seen. Has anyone ever been able to harvest yeast from a commercial brewery bottle before and how did you go about it? I'd love to experiment with it.

Do some searching. There's tons of info on this. You can successfully harvest commercial or homebrew yeast out of bottles and build it back up in starters until you have enough to brew a batch. I recently pulled the yeast out of two bombers of my homebrew blonde and successfully fermented a 5 gallon batch of Brown ale a week later.

I've done it several times. Do some research.

I keep starter wort (1.030) in mason jars, and will add about 6 ozs to a bottle and stick an airlock on it. You can get airlock stoppers that fit bottles. I usually pour the dregs of several bottles into one with the starter wort. When pouring the dregs, I wipe the tops of the bottles with 90% alcohol to kill anything.

Depending on the age of the yeast, it can take a week (or more) to reproduce and ferment the starter wort. And sometimes it's dead.

That's a good idea I'll get me a stopper that'll fit the bottle. Thanks Calder.

And yeah, "did some research" before posting. Found a ton of threads asking about specifics into the process without anything clear on how to start...hence the post.

I usually make up about a gallon of starter wort and keep it in the fridge. Boiled to about 1.030 (1 lb LME added to 1 gallon). Pour it in pint mason jars and heat them in a water bath (I do not use a pressure cooker). Place caps on the jars and let them cool. Providing the jars reach 160 F (I like to push it to boiling) they will be sanitized. Place cooled jars in the fridge. Make sure you use proper Mason jar lids, the ones with the flat lids and the screw-on covers. Re-using the ones that come with spaghetti sauce, will be impossible to get off.

Makes it handy for making any starters and harvesting yeast. Also, once the yeast have gone thru the initial small amount of wort, you will need to cool the bottle to drop the yeast, pour off the liquid, and then make a new 'starter' with increased wort volume.

Lots of guys just use the add wort and go method, I prefer the plate method, this guarantees that I will only get yeast and not something else taking over my beer. I don't want to waste the precious amber nectar from heaven.

The method: you take a sample of the dregs with an inoculation needle and wipe it over the agar plate surface. If you do it right you will get a bunch of colonies and some single colonies grown from a single cell. Grab the single cell colonies that you can see (1 or more) that are not affected by the other colonies or anything else on the plate growing from what was in the bottle. You can then grow this out in a slant containing sterilized wort. You then step this up until you have pitching quantities, just as if growing from a slant (there is a wiki about that basically x5 volume steps).

Like I said I'm a little up tight (my wife says obsessed) about this but it guarantees a good out come as you have isolated the yeast and stepped it up in a controlled manner. Both versions works I'm just more comfortable with this method.

Clem

I recently ran through the back catalog of Basic Brewing Radio and the 03-11-10 episode - Starter Aeration Experiment was super informative. In it the experimenter, Sean Terrill, reported 25% (I may be not remembering the exact percentage correctly but it was significant) more yeast cells than an airlocked starter by loosely covering the flask with sanitized tin foil. Agitating the flask or using a stir plate will add further increases.

Basic Brewing Radio is a great listen if you're new to brewing & building up starters like I am.

I have successfully harvested yeast twice just using a bottle of Malta and the dregs from the bottle of a beer known to have yeast sediment in it. Malta is basically an non-fermented malt and hop beverage that tastes awful. Costs 90 cents a bottle and seems to do the job.

I just did this with a bottle of my own hefeweizen, some pranqster, and one of my own apa's.

Add 50g of dme to 500ml of water and boil for a couple mins, I usually add some yeast nutrient.
Cool and add to a jar you ran some starsan through.
Shake the crap out of it with a lid on it to aerate.
Start drinking and add the dregs of a couple bottles to the jar with the wort. Cover it in some foil you sprayed with starsan.
Swirl it every once and a while when your'e in the kitchen and in ~3 days it should be enough to add to a 2l batch of wort. (200g of dme to 2l of water)
Let that go like a regular starter (foil on top, swirl everytime you think about it), chill, decant, pitch like normal.