Attenuation of Brett-B?

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Calder

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What attenuation can you expect from Brett-B as the primary strain?

I started an All-Brett on 12/30/10 using a starter of WLP650 (Brett-B).

It got off to a quick start (at 12 hours it was going well). Kraeusen reached almost 1.5 inches (and I had added FermCapS to the fermenter).

Last night (3 days) Kraeusen had dropped, and bubbling had slowed considerably (it's a glass carboy with a rubber bung, so I think I can trust it). So I took a sample. Tasted like a fruity Belgian (pretty good), but SG was only 1.020, down from a start of 1.055. I was hoping to end up closer to 1.010.

The recipe was simple, 5.5 lbs 2-row, 0.5 lbs acid, mashed at 150, made up to 1.055 using LME. Calculated what the SG should be and then measured to confirm it was correct.

Tonight it had slowed down a lot more and has started to clear (about 1 bubble/minute). I know there are probably a couple more points to go, but this seems a little higher that what I was expecting.

Anyone else have any experience with this yeast?

The yeast claims to be good down to 60F, so I think it is OK. It's in a basement with the air temperature about 65, and is sitting on some insulation to protect it from the concrete floor temperature.

It's my first time using this yeast, so I am curious. But it will stay right where it is for several more weeks.
 
When brett is used for primary fermentation with proper aeration it generally ferments like sacc and will reach a similar FG. However, it will often ferment down a few points more within 6-8 weeks and reach a stable FG. I found this information from Vinnie at Russian River and although I haven't fermented an all-brett beer yet -- I just started the starter tonight -- I assume he knows what he is talking about.
 
I think it just got cold and the yeast dropped out. It was on the concrete floor for the first couple of days. Then I moved it on the insulation, but i think I was too late.

Last night I checked the beer temp and it was 63 F at the surface. If it had gotten colder at the bottom the yeast could well have gone to sleep. I added 6 ozs of sugar in 2 pints and poured it in while at about 120 F. Figured it would warm the beer up about 2 degrees (2 pints added to 50 pints at 60 F), and give the yeast a little more to chew on. It started up again quickly and is churning well one day later. Hopefully the insulation on the bottom will keep the yeast warmer. It's a glass carboy, with almost 7 gallons in it; I'm not moving it. Might have to see if the wife has a heating blanket if it stalls again.
 
Just wanted to update some observations to see if anyone else has found the same.

My all-Brett beer seemed to stop at 1.018, about 70% attenuation. Very nice and fruity, but too sweet for me. I have since added active Pacman yeast that is slowly taking it down. Now at 1.012 and dropping - tasting much better (less sweet; I really don't like sweet). This batch had 0.5 lbs of acid malt in 6 gallons.

I also used the same yeast in a couple of test single gallon batches. These used malt extract and did not have any acid malt. Both were different recipes, both used the Brett yeast from the same starter as the main batch, and both only went to about 30% attenuation. I've since added some sac yeast and both, and both have come down considerably and still going, so they both had lots of fermentables.

My conclusion is that if you want to do an all-brett beer, you need an acid wort to get any kind of decent attenuation, and if you want it dry, you should add an active yeast starter after the sac has done it's work.

I found some research on-line, the Brettanomyces Project (my apologies to the author that I don't remember his name) that found that Brett attenuated better with more acid worts. Using the same yeast as I used (WLP650), he found attenuation rates ranging from about 25% to 60% depending on the acidity of the wort.
 
Calder said:
Just wanted to update some observations to see if anyone else has found the same.

My all-Brett beer seemed to stop at 1.018, about 70% attenuation. Very nice and fruity, but too sweet for me. I have since added active Pacman yeast that is slowly taking it down. Now at 1.012 and dropping - tasting much better (less sweet; I really don't like sweet). This batch had 0.5 lbs of acid malt in 6 gallons.

I also used the same yeast in a couple of test single gallon batches. These used malt extract and did not have any acid malt. Both were different recipes, both used the Brett yeast from the same starter as the main batch, and both only went to about 30% attenuation. I've since added some sac yeast and both, and both have come down considerably and still going, so they both had lots of fermentables.

My conclusion is that if you want to do an all-brett beer, you need an acid wort to get any kind of decent attenuation, and if you want it dry, you should add an active yeast starter after the sac has done it's work.

I found some research on-line, the Brettanomyces Project (my apologies to the author that I don't remember his name) that found that Brett attenuated better with more acid worts. Using the same yeast as I used (WLP650), he found attenuation rates ranging from about 25% to 60% depending on the acidity of the wort.
Click to expand...

Good choice on the Pacman. I love how it chews through at around 63F. It dries out a beer really well. Are you kegging or bottling? Here's the link to the Brett Project. Good read.
 
Calder, do you happen to remember what the ideal pH for the brett is? I figure it would be fairly easy to acidify with some lactic to get the magic number for them.
 
I seem to remember reading in Jeff Sparrow's book on wild yeast, he says that lambics (traditionally) have a near 100% attenuation. The reason being, they are allowed to ferment for three years in barrels, allowing the bacteria to get needed oxygen, before consuming.

I know you just used Brett in this, but perhaps more time will see a further (albeit slow) drop in gravity?
 
YogiBearMead726 said:
I seem to remember reading in Jeff Sparrow's book on wild yeast, he says that lambics (traditionally) have a near 100% attenuation. The reason being, they are allowed to ferment for three years in barrels, allowing the bacteria to get needed oxygen, before consuming.

I know you just used Brett in this, but perhaps more time will see a further (albeit slow) drop in gravity?
Click to expand...

There is a relationship with the other bugs that push the brett to become super attenuative from my understanding...brett is not super attenuative alone or with sacc. Granted I have only brewed with brett as a secondary at this point so that is based off of what I have read in preperation for a 100% brett that I'm building a pitch for right now.
 
Bensiff said:
Calder, do you happen to remember what the ideal pH for the brett is? I figure it would be fairly easy to acidify with some lactic to get the magic number for them.
Click to expand...

If you find out, please let me know. I don't know what mine was, I just used 0.5 lbs of acid malt to 5 gallons. I didn't measure the PH, I didn't realize it was so critical.

The Brett project didn't give any recommendations, but went down to 3.08 (3 grams/liter of lactic acid) in it's tests, and still didn't necessarily reach the optimum.
 
Bensiff said:
Calder, do you happen to remember what the ideal pH for the brett is? I figure it would be fairly easy to acidify with some lactic to get the magic number for them.
Click to expand...

Here is what Sparrow has to say

"Brettanomyces classically ferment best in worts with a lower pH (after primary fermentation has begun) with or without the presence of oxygen but, unlike saccharomyces, prefer aerobic conditions. Brettanomyces will cease to reproduce below a pH of about 3.4."

Hope this helps and sorry for any gramatical errors.
 
Thanks Hoosier, that was what I was thinking of I just couldn't remember where I had read it.
 

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