Attenuation and Environment

[Gavagai]

I've recently moved from Massachusetts to Seattle, and have noticed that brewing here, my beers (I've fermented 5 here so far) have been taking longer to ferment and finishing sweeter—5%–10% higher apparent attenuation. I haven't been using more specialty grains or pitching at a different rate. (I make starters for full batches.) I don't think the yeast is any older—although I admit I haven't been paying close attention. My aeration procedure is the same. The ambient temperature of the fermentation room is a steady 68F, based on what the strip thermometers on my fermenters read post-fermentation. In Massachusetts the average temp was probably about the same, but there was much more fluctuation. On the last few the bulk DME that I've been using may have been a different brand, but I'm not sure. I'm stumped. Any ideas?

 

[Yooper]

I've recently moved from Massachusetts to Seattle, and have noticed that brewing here, my beers (I've fermented 5 here so far) have been taking longer to ferment and finishing sweeter—5%–10% higher apparent attenuation. I haven't been using more specialty grains or pitching at a different rate. (I make starters for full batches.) I don't think the yeast is any older—although I admit I haven't been paying close attention. My aeration procedure is the same. The ambient temperature of the fermentation room is a steady 68F, based on what the strip thermometers on my fermenters read post-fermentation. In Massachusetts the average temp was probably about the same, but there was much more fluctuation. I'm stumped. Any ideas?

I assume your water has changed? Are you mashing with a different water source, and possibly having some water chemistry issues?

 

[Gavagai]

I've thought about water, but I was under the impression that having very soft water—which Seattle has—is ideal for extract brewers. I'm trying to go all grain ATM, but all of the batches in question have been extract + specialty. So I don't think that's the answer, unless I'm somehow seriously overextracting the specialty grains, which I guess is possible—but we haven't used more than a pound in any of them. Is chlorine ever a problem in yeast starters? Because I'm not sure I campdenized all of my starters.

 

[Clementine]

The yeast sense the proximity of all those wonderful hop fields and were compensating for the additional IBUs

Seriously, if we look at the variables, temp, pressure, water... not much else, you have ruled out temp, pressure it is not Denver both places are pretty costal, so that leaves the water. Try using bottled water for the starter and see if it get you anywhere?

Clem

 

[Gavagai]

I'll try that.

I guess one thing that has changed, ironically, is that I've started adding yeast nutrient to my starters, which turns them a bit grey. Not sure if that's normal. I may have added too much.

 

[samc]

The amount of yeast nutrient I add to a starter is so small that it does not effect the color of the starter. For Wyeast Nutrient it is less than a gram.