Will WLP007 produce esters/off flavors late in fermentation?

[HeadyG]

I've got an imperial chocolate stout in my fermenter. OG was 1.078 and I'm hoping to get it down to 1.016 or so. I oxygenated for 60 seconds before pitching four packs of WLP007 at 68 degrees at 4 pm Sunday, fermentation began by 10 pm. I kept the ambient temp at 62-63 and the fermometer read 67-68 for the first couple days as the yeast did their thing. Fermentation slowed Wednesday so I moved the fermenter to a warmer room, gave it a shake and let it warm to 70. It remained slow Thursday so I set the thermostat to 72 and left for the day. When I got home the ambient temp around the fermenter was 77 and the fermometer read 74. I immediately turned down the thermostat and the fermometer stabilized at 72. Bubbling has pretty much stopped in the blowoff jar and I think the fermentation is largely finished.

It is my understanding that most ester production will happen early in the fermentation. Could letting it warm that much at the end of fermentation negatively affect the beer? I plan to leave it in primary for 3-4 weeks to clean up and condition. Thanks a lot.

 

[JoeMamasIPA]

You will be more than fine, the yeast are just cleaning up. Just be careful that you don't bring the temp too far back down or they will want to drop out and stop cleaning up. How big of a batch for 4 packs of yeast?

 

[HeadyG]

You will be more than fine, the yeast are just cleaning up. Just be careful that you don't bring the temp too far back down or they will want to drop out and stop cleaning up. How big of a batch for 4 packs of yeast?

OK good, thank you. Yeah I just checked and it's hanging tough at 72 right now, which is where I'll leave it for the next few days at least. I'll pull a sample on Sunday and see where it's at.

It's a 5.5 gallon batch. I tried a similar brew last winter but only pitched 2 packs and didn't aerate very well (only swished) and it stalled out on me. I was aiming for a higher OG on the current batch but I may have mashed a little hot and my efficiency was only around 60%. From what I read, the higher gravity would require 400 billion cells or more, and I haven't attempted making a starter yet. It's only my second AG batch so I'm very much still learning.

 

[balrog]

Put a number on "mashed a little hot"

 

[HeadyG]

Put a number on "mashed a little hot"

Mistakes were made! I forgot to grab the temperature when I mashed in but the strike water was at 168. It could have been a couple degrees north of 154 when I sealed up the mashtun. Had to call an audible on the fly while draining the mash tun because the line got clogged and the heating sparge water got into the low 170s while we strained the mash into the kettle. I cooled it with additional water but it might have been 169-170 when we batch sparged. I really don't think we were way off in either case. It was a little hectic and I definitely learned my lesson. I will be spot on next time.

 

[Mer-man]

I am just going to say that one should not rely on packs of yeast -- make a starter so you know the yeast is active

 

[rburrelli]

I am just going to say that one should not rely on packs of yeast -- make a starter so you know the yeast is active

Yep. Four packs of yeast is quite an expensive way to make beer. But you are probably not concerned about the cost, only the outcome. Good luck.

 

[balrog]

Mistakes were made! I forgot to grab the temperature when I mashed in but the strike water was at 168. It could have been a couple degrees north of 154 when I sealed up the mashtun. Had to call an audible on the fly while draining the mash tun because the line got clogged and the heating sparge water got into the low 170s while we strained the mash into the kettle. I cooled it with additional water but it might have been 169-170 when we batch sparged. I really don't think we were way off in either case. It was a little hectic and I definitely learned my lesson. I will be spot on next time.

A couple degrees won't make much a difference. 158 will make a different ferementability profile of sugars than 148 however--just pointing out what magnitude of a mash-temp change you would notice. Also, sparge temp really won't matter. The temp to think about is really the conversion temp, and once the pieces have gelatenized and made starch available to the enzyme, if not denatured by heat, then conversion is done and you can let temp wallow fairly all over as you are just soaking flavor into the mash. I BIAB and grind very fine and conversion is likely done in 10-15m. I mash 45-60 as I notice flavor difference in the end result if I mash 20m, I am presuming less flavor from the grain soaked into the wort.