Safbrew WB-06

[Prymal]

I pitched WB-06 for the first time Sunday into a 1.081 Hefe (yeah I know that is huge for a Hefe). The issue i am having is temp control. I use a Swamp cooler setup and have never had an issue keeping the beer fermenting between 62 and 65 but for some reason this beer is putting off a crazy amount of heat. I caught the temp creeping up to 68 twice yesterday. Should I expect this to turn over "Bananay" or do though esters show up at higher temps then 68?

 

[Nateo]

If you overpitched (which is really easy to do with that strain) you won't get a whole lot of banana. Higher temps trend toward banana, lower temps (60-ish) trends toward clove, but overpitching will siginificantly cut down on the amount of banana.

How much yeast did you pitch?

 

[Prymal]

I pitched 2 packets, based on the Beer Smith 2.0 Pitching calc I needed 408 billion cells and the yeast as 4 months old so viablility took the 2 packets down to about 340 billion.

 

[Nateo]

With that yeast, you'll get better results pitching 0.5m/ml/*P. Dry yeast viability is reliably 90% even if it's a year or older. Dry yeast contains about 20b cells per gram, so @ 20b/g x 23g (two 11.5g sachets) x 0.90 (90% viability) = 414b cells.

So for a 5 gallon batch (~20,000ml) of 1.081 (19.5*P), you'd need 500,000 x 20,000 x 19.5 = 195,000,000,000 = 195b cells.

 

[Prymal]

Sorry, You lost me with that math. I think that you are showing me that i over pitched double

 

[Nateo]

Sorry, You lost me with that math. I think that you are showing me that i over pitched double

Yeah, my quick calculations tell me you pitched about twice as much as I would have. WB-06 has a bad reputation with homebrewers, but probrewers love it. Wheat strains tend to lose their distinctive character if overpitched, and it's really easy for homebrewers to overpitch this particular strain. So homebrewers overpitch, it doesn't taste like a weizen, so they blame the yeast, not their pitching rate.

I've never tried that strain in a beer that strong, and fermentation byproducts are more concentrated in stronger beers, so it might end up fine, with just as much banana as you want.

"Standard" pitching rate for ales is 0.75m cells per ml per degree Plato. So 0.75m/ml/*P. For phenolic yeasts, and beers you want to attenuate well (think big Belgians), some people like to pitch at a lower rate, like 0.5m/ml/*P. For lagers people generally use 1.5m/ml/*P.

Slightly underpitching is reported to increase the production of esters and phenols. Slightly underpitching also increases the number of "daughter" cells, that are younger, with more vigor, than their "parent" cells. So it's counterintuitive, but slightly underpitching can result in higher attenuation (assuming all other nutritional needs are met).

 

[Nateo]

Did you properly rehydrate the yeast, or just sprinkle it on top? If you didn't, you probably killed half the yeast, in which case you ended up with a good pitching rate.

 

[Prymal]

Awesome, Great information. I was actually hoping to suppress the banana by fermenting in the lower range so if i ultimatly did that by over pitching it guess it all works out.

 

[Nateo]

I'm interested to see what happens with the high gravity, but my past experiences tell me you probably won't have too much banana.

 

[beargrylls]

how did this turn out? i am fermenting a wit right now with wb-06 at about 65 degrees

 

[Prymal]

I am not sure, it is a weird beer. The yeast actually fermented out to 1.011 which was very surprising. The beer is still carbing up in the keg but the one sample I pulled wasn't very pleasant. Some clove and lots of citrus which was a surprise.

 

[nate_ive]

About a month back I brewed a normal strength hefe with wb-06 and it had a lot citrus which is fading right now and the banana is shining through. A little aging might clean up the citrus.