Attenuation of the 4 day wonder yeast: Wyeast 3942

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Well-Known Member
Jul 30, 2007
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Lincoln, ND
Last Friday afternoon I did another brew. According to Beer Calculus, it would be a pretty good sized beer (about 6.8% ABV). The yeast I used was Wyeast Belgian Wheat 3942 - what I'm wondering is what's up with the fermentation? I'd say fermentation has lasted about 4 days. It really started Friday evening and went until about Tuesday evening.

Granted, it took off well (blew off my airlock and made a mess until I put on a blow off tube) but is it possible that it has attenuated in 4 days? It's always had the temperature necessary by being kept in a room that's between 68 and 75 degrees of ambient temperature. Either way, to be on the safe side, I won't bottle until Saturday, assuming the FG looks all right.

Can anyone who's used this yeast, or other wheat yeasts tell me if it's a characteristic to have a short, robust fermentation?
Not only is it possible, it more than likely that your beer has completed fermentation.

Check your FG and go from there. My last two batches of Dry Irish Stout and Oatmeal Stout hit their FG's in less than 30hrs.
Wow. That'd be pretty impressive. I suppose it's all up to the FG now. The funny thing is, I only broke one of the two sections of my smack pack nutrient sack (didn't find out until I pitched). Although I did have a Bavarian wheat yeast that fermented in about 5 days or less - maybe it's a wheat yeast thing?

Btw, just to make sure, when I take the FG, what temperature should the beer be for an accurate reading? While I am it, I guess I'd just use my auto siphon to draw out a little bit for the hydrometer? If there's an easier way, I'd be glad to know. : )
The temperature will depend on how your hydrometer is calibrated. It will either be 60deg or 68deg, but it should say so on it somewhere.

You can use an auto siphon just make sure you remove it from the beer before your cylinder is full to account for the extra beer in the tubing.

I now own two Wine Thiefs and it is so much easier to get your gravity using them.