Harvesting yeast from commerical beers

[poppalarge]

Hello.

If I were to harvest yeast from a commercial beer, what's the minimum amount I need?

Can I do it with a single 1ltr bottle? Or do I need more?

 

[Denny]

You put the yeast into a very small amount of 1.020 wort (like 1/2 cup) and step it up several times until you get enough to brew with.

 

[stpug]

I've harvest the settled yeast in the bottom 1/2" from a single 12 oz bottle and done just like Denny said (1/2 cup weak starter wort and build it up). I have several strains this way and have used them successfully. I've found that the first step in the 1/2 cup weak wort can take 2-6 days to come back to life depending on how the bottle was handled, how long the yeast has been sitting there, and the ABV of the beer sitting on top.

For example:
PranQster (California, fairly local) yeast blend bounced right back in a day or two.
Westmalle Tripel (Belgium, worlds away) took 4-5 days before I noticed any change in the starter wort.

 

[flars]

Is the yeast in a bottle of commercial beer the yeast used in brewing or is it a different yeast for carbonating? Thought I would ask after looking at the spec sheet for Safbrew F-2.

 

[butterpants]

I've harvest the settled yeast in the bottom 1/2" from a single 12 oz bottle and done just like Denny said (1/2 cup weak starter wort and build it up). I have several strains this way and have used them successfully. I've found that the first step in the 1/2 cup weak wort can take 2-6 days to come back to life depending on how the bottle was handled, how long the yeast has been sitting there, and the ABV of the beer sitting on top.

For example:
PranQster (California, fairly local) yeast blend bounced right back in a day or two.
Westmalle Tripel (Belgium, worlds away) took 4-5 days before I noticed any change in the starter wort.

Isn't 3787 the Westmalle strain? Can't imagine why you would grow it from dregs if it's commercially available...... what am I missing?

 

[TexanRudeboy]

Is the yeast in a bottle of commercial beer the yeast used in brewing or is it a different yeast for carbonating? Thought I would ask after looking at the spec sheet for Safbrew F-2.

Depends on the beer. Some filter the original yeast out and carb with a neutral yeast. Contact the brewery in question. Most are more than happy to help home brewers with questions.

 

[TexanRudeboy]

Isn't 3787 the Westmalle strain? Can't imagine why you would grow it from dregs if it's commercially available...... what am I missing?

Why pay $6-7 when it comes free with good beer you just drank?

 

[butterpants]

Why pay $6-7 when it comes free with good beer you just drank?

I guess.... seems like a hell of lot of work to save 6$.

 

[Denny]

Is the yeast in a bottle of commercial beer the yeast used in brewing or is it a different yeast for carbonating? Thought I would ask after looking at the spec sheet for Safbrew F-2.

It is almost always the main strain. The breweries have so much of it around they often have to dispose of it if they don't use it. Most of the time, it doesn't make economic sense to use another strain.

 

[Denny]

Isn't 3787 the Westmalle strain? Can't imagine why you would grow it from dregs if it's commercially available...... what am I missing?

IMO, you're not missing anything. Although it can be fun to culture yeast from a bottle, if it's a high gravity beer it isn't worth the effort if you can buy it, IMO.

 

[Denny]

Why pay $6-7 when it comes free with good beer you just drank?

Becasue in the case i=of 3787, it very likely comes from a high gravity beer that's been imported and is likely to be older. In that case, you get much healthier yeast by buying it.