Got a special bottle-conditioned beer you'd like to pinch the yeast from? I do. This is my 3rd successful harvest so I thought I'd throw out a how-to. It's ridiculously easy!

One-step a 1L flask, stopper, and airlock. Boil up a mini-wort of 2 cups water, 1/2 cup DME, and 1/4 tsp of yeast nutrient. Dump the wort into the sanitized flask and cover tightly with a piece of tin foil. NOTE the flask must be tempered glass to handle the heat! If you're using something else to ferment in, let the wort cool in the (covered) pot first.

Set the flask aside to cool to room temp. Meanwhile, bring the bottle-conditioned brew to room temp (if not already). Once the wort is completely cooled, carefully pour off the brew into a glass to enjoy, leaving behind the yeast. Slosh the remaining beer in the bottle to re-suspend the yeast and pour it into the flask. Button it up with an airlock filled with cheapo vodka and stash it somewhere warm!

Because there's likely very little viable yeast in the bottle, patience is a must. Signs of fermentation may take a week or more. Eventually though, you should get some krausen and bubbling in the airlock. Once the bubbling finishes, pour off the the beer and taste test. Is it good? Dump the fresh yeast into a sanitized canning jar and stuff it in the fridge. It should stay viable for up to six months or so, but it's always wise to make a starter to re-verify viability and taste.

Here's my just completed Chimay harvest. Took 5 days before fermentation started but then went crazy and grew a fine batch of yeast. Tastes just like Chimay too. Looking forward to doing a proper Trappist soon with this one. That's one-step in the canning jar, BTW...

very nice Jkarp thanks for the info

Thanks for the tutorial jkarp.

This is great, I needed it all in one outline.

4 questions:
1) Can boiled water be used in the airlock? It's a one-way passage so I don't know why vodka would have to be used, or even boiled water. I just don't have cheapo vodka on hand

2)When a new batch of beer is ready for the fresh yeast, any additional prep, besides bringing the fresh yeast to room temp and doing a test starter? Just pitch it and let it work?

3) What if I want to use the trub for this process? Does nuterient still need to be added or is there enough in the wort/slurry?

4) you refer to tasting the starter beer - does it taste good? What if it tastes bad - infection and down the drain it goes?

Thank you so much for posting the process. I want to harvest my liquid wheat yeast.

Michelle

+10 jkarp !!!!
Great info !!!

Not recommended. An airlock really isn't one-way. Any pressure differential between the flask and outside can draw the liquid into the fermenting beer. Vodka is ideal because it's harmless to the wort. Sanitizer can be used but if too much were to get pulled into the wort, you risk killing off the yeast.



That's it. If you've got enough yeast (and it smells good), you can skip the starter. I did when I re-used my Wit yeast. I had so much yeast it was instant krausen.



Here's the link to where I harvested yeast from my first Wit batch. I didn't add any nutrient. Wit yeast doesn't need any encouragement.



Yup. If the starter doesn't taste good, it's a given you won't like the beer it'll make.

This looks like the easiest and cleanest (most sanitized) way to bottom crop and I really don’t see any reason for a wash (or should I say a second wash) as long as you are careful not to get too much turb in your yeast collection bottle. I’m going to use this method when I bottle my cascade pale ale over the holiday weekend.

I do have 2 questions for you jkarp though….

1) Have you ever tried top cropping?? If so, what procedure did you use? (using the MRB kegs)

2) From what I’ve read, it looks like the lag stage is the best time to harvest yeast. For top cropping, I think it would be fairly easy, but since I don’t rack my ales, unless there is a need, how would you do this. If I had a conical fermentor, this would be a piece of cake. What I thought about doing was putting something behind the keg to tilt it forward, that way more turb would be at the front and it would be easier to harvest it at this time. Or do you think I would just clog the spout?

To be honest, I'm disinclined to open a keg mid-fermentation. Waiting for the yeast to flocculate out and grab it after bottling is just too easy (and safe) IMO.

Good stuff jkarp!

Wikify!

+1 wiki this bad boy!!
Awesome job jkarp!!!!!