Double fermentation all grain

[robbo007]

Hi all,
Done a few all grain brews and all seems to be working now. Just wondering how to do a double fermentation all grain brew? I've read some of the famous Belgium Trappist ales are double and triple fermented.

Do I just add a second lot of yeast to the fermentation tank after the first fermentation process is over? Or after I get my gravity reading down to 1012?

Thanks,
Rob

 

[skeezerpleezer]

That usually means it is bottle conditioned and/or has Brett or bacteria added.

 

[robbo007]

I normally ferment in my tank then bottle to carbonate. Is this what you mean?

 

[skeezerpleezer]

Yes. Adding sugar during bottling results in another fermentation (which is what carbonates it). Sometimes places use other yeasts such as champagne, wine, Brett, etc to do this also.

 

[robbo007]

Ok. So I'm technically doing a double fermentation then

 

[skeezerpleezer]

Yes.

Keep in mind though, that a lot of them may use different yeasts. For instance, I may ferment with a Belgian Abbey, then ferment more with the Roselare bug blend, then bottle with Champagne yeast.

 

[robbo007]

So you would use three different yeasts in the first fermentation process? How long would this entire 3 yeast fermentation go for? My IPA normally takes 3-4weeks.

How do you know when to add the next yeast?

 

[chickypad]

So you would use three different yeasts in the first fermentation process? How long would this entire 3 yeast fermentation go for? My IPA normally takes 3-4weeks.

How do you know when to add the next yeast?

Keep in mind skeezer is talking about advanced styles of beers here - like a lambic or flanders red. You're not going to do this on an IPA. Adding the different yeasts are done for a specific purpose - for example the Roselare blend adds souring organisms to make a sour beer, then takes 18 months or more to age. The champagne yeast might be used in a high alcohol content beer, and/or one that has been aging a long time, in order to get it to carbonate properly. You don't want to just go throwing a bunch of different yeasts at a beer without some goal in mind.