Weihenstephan yeast low attenuation

Last weekend (11th) I brewed ~46 liters of Weizen that I didvided in two batches to experiment two yeast. Fermentis Safbrew WB-06 and Wyeast Weihenstephan Weizen. WB-06 was sprinkled on the wort surface and Weihenstephan was pitched directly from an activated Activator pouch (it swelled the pouch within an hour). The wort OG was 1.052 and cold to ~20°C. Batches were aerated by the mean of allowing the cold wort to fall down the fermentors then vigorously stirred with spoon at least three times within 6 hours after pitching the yeasts. Three days later the WB-06 was done at 1.012 (estimated FG) but the Weihenstephan was still ~25. Fermentors were at 18-22°C all the time. WB-06 made a ~1-1/2" thick krausen while the Weihenstephan blowed off a lot (on the floor) then calm down ~24 hours later. Today Weihenstephan was at 1.020 (8 days later). It look like it's still fermenting but I find it to be a bit sluggish. I had to rack it off lee as I need the yeast for another recipe. I siphon a bit more yeast on the secondary. Wyeast say it should attenuate ~75% (1.052 X 75% = 1.013).

What could be the possible cause for the slow/sluggish performance?

1)Too much yeast went out in the intense blow off (It's not the first time this happen to me and it never created such a problem for me).

2)Too cold (according to Wyeast it was within the range... on the low end but...).

3)It's known to be slow to attenuate (not mentioned on Wyeast web site).

4)Should have made a starter anyway (wasn't supposed too for this OG and batch volume).

5)Not enough aeration (Then why WB-06 performed so well?!).

6)Else.

Today I brewed a Dunkelweizen that I pictched directly on the Weihenstephan yeast cake. I made some further aeration.

My best guess is that its a bit too cold. If you are on the low end of Wyeast's recommended range, I'd try getting the temp to a constant 22*C. I like to ferment this yeast cool (~17-18C) for a few days, then let it warm up to around 21-22C.

You pitched several times more of the dry yeast than the liquid.

I used the same yeast on a Honey Apple Cyder (that's how I'm spelling it for this one).

The OG was 1.100. I expected a 75% attenuation at 1.025, but it kept getting lower and lower...now it's 1.000.

I believe it's the temperature you're fermenting at. My hard apple cider took 2.5 weeks to reach 75% attenuation fermenting in a room at 17*C, which is below the recommended temperatures for this yeast by a tiny margin.

Although I didn't make a starter OR aerate my juice, other than giving it a good shake before pitching the yeast.

I'm brewing a clementine Hefe right now in my 20-22*C apartment that I suspect will be nearly done next time I check on it. If I check tomorrow night it will have been 6 days since I pitched.

I had problems with that yeast on my first hefe. Final gravity came out to a way too high 1.018, about .005 high than I would have liked, but I think that I should have upped the temperature at the end to finish it off. Ill have to give the recipe another run and see if the results repeat

The Dunkelweizen I did and put on the Weizen yeast cake (Weihenstephan) yesterday is now bowing off (barfing) vigorously. I think the yeast is very healthy. I'll guess it's either the temperature (during the spring months, my basement is not very temperature stable at all) or it's simply the way this strain is. I moved the Weizen secondary to the first floor where it's more stable and around 20-24°C and it's active again. Let's hope for the best.

I've used that strain many times and have always gotten ~ 75% attenuation. I would say it under attenuated because you didn't pitch enough yeast. If you would have made a starter it would have been a better comparison.

Definitely underpitched. Your temps are fine, though. I had a pack of this yeast that I made a big 4L starter for last week, and used that on 10 gallons. I brewed the hefe on Friday, had activity by Friday night, and I'm currently at 1.013 (down from 1.050).

You also may have lost a good amount of viable yeast in the blowoff.

Beer turned out fine (read excellent). I rouse the yest a couple of time and it "waked up" the yeast. Same thing for the Dunkel batch right after. Reached FG, in both case, pretty close.

Paco said:

Beer turned out fine (read excellent). I rouse the yest a couple of time and it "waked up" the yeast. Same thing for the Dunkel batch right after. Reached FG, in both case, pretty close.

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What differences can you detect between the two Hefe's? I always use the Wyeast 3068 for mine... just wondering if there was much of a taste difference with the dry yeast. Thanks.

I also just brewed a Weissbier with Weinhenstephan last weekend, it took about 8 hours to get going, but it had a very vigorous fermentation that was "done" in about 2 days. Stayed @ about 66f-67f and after three days was down to 1.011, from 1.049. It looks like I could be able to bottle this weekend. Overall I think that is a pretty good yeast.

Passedpawn,

The two beers are good to me and from the feedback I had from my brewing club. Overall most prefer the WY 3068 but one said the WB-06 was more to style... I personally like both but I prefer WY 3068 for the aroma and the head retention.

It was interesting to compare the two yeast against each other from the very same wort. It was also very interesting to see how they behave quite differently.

With the recent price increase of WB-06 and for the clove/banana aroma I'd recommend WY 3068 but WB-06 is a nice back up/substitute. I also tried Danstar German wheat with the same recipe some months ago and WB-06 seem a lot more like Weizen to me...

I still have a couple of WB-06 packets and I want to try to ferment it much higher to see what happen.


Whiskey, odd isn't it?!

I'm drinking a hefe right now brewed with 3068. It's quite good even though it needs another week or two in the bottle.

My 3068 took the OG 1.045 to FG 1.009 in about 6 days. According to Beersmith that's about a 79% attenuation. I didn't have the blow off that you had, though I was expecting it.

WYeast 3068 is my favorite weizen yeast (maybe because Weihenstephaner is my favorite weizen) and I've used it a lot. Every time I've used it, it blew through the air lock with a BIG bubble over in the first 48 hours (even though I use a 6.5 gal carboy for 5.25 gal wort). Then the fermentation slows and lasts another week or more with the yeast still heavily in suspension. I've had great success racking to a secondary after 5-7 days and leaving it there for another 12-14 days to finish and settle out.

I like to slightly underpitch the 3068 .I take it you brewed about 12 gallons of beer and split it dry in one and the Activator in the other @1.052 you really underpitched the 3068. I did 11 gallons @1.056 two weeks ago and made a 3 liter starter for it and it was still uderpitched. Mr. Malty say's 4 liters + one pack on a stir plate .

I feel thats why it took longer than the dry to finish

I reused the very same yeast that I harvested from the May batch. It's been in the fridge for ~2 months. Made a small starter to wake it up. This time ferment at ~22-24°C. After three days, the FG was 1.008 (OG 1.053). I also mash much lower (~63°C). Only other change is 10% more wheat malt (60% total).

This time it's exactly as I expected.

I have used this yeast on 3 different occasions and the weizen beer turned out fantastic every time. The first time I pitched a 2L starter at 68F,FG=1.012 at 7 days,second time I pitched a 2L starter at 70F,FG=1.012 at 14 days, the third time I pitched 2L starter at 65F,FG= 1.012 at 14 days. I listened to Jamils podcast on brewing wheat beers and he likes to start cooler then finish warm. That is what I did on the last beer (franziskaner clone) fermentation started at 65F and finished at 70F. It was by far the best beer I have ever brewed, you could not tell the difference between the clone or mine except for color(mine was a bit to dark). I think I am going to make another wheat beer right now, good luck!