Safale US 04 Question

I brewed a Nut Brown Ale last Thursday, recipe is:

10.00 lb Pale Malt, Maris Otter (3.0 SRM)
2.00 lb Pale Malt (2 Row) US (2.0 SRM)
0.50 lb Caramel/Crystal Malt - 40L (40.0 SRM)
0.50 lb Victory Malt (25.0 SRM)
0.35 lb Black (Patent) Malt (500.0 SRM)

Had an OG of 1.075 (had a little better efficiency than I was planning on). Anyway, I used safale us 04 yeast and fermentation appears to have stopped and I took an FG yesterday and it was 1.028, and another one today and it hasn't changed. I'm not sure if fermentation has stalled because I know 04 doesn't have high attenuation. Is this about the most I'm going to get from this yeast or has it stalled?

i would check it again tomorrow or saturday. if it has not changed still, it would seem to me that it would be safe to transfer or do whatever it is you need to do.

That's only like 63% attenuation so far - S-04 should definitely be able to take it lower. Is there still krausen present or has it starting floccing?

What temp and how long was your mash?

What temp are you fermenting at? You could try raising the temp a bit, and get some of the yeast back in suspension with a gentle swirl to see if they will take it down a bit further.

Mashed for an hour. Temp was at 155 when it started, checked a half hour later and it was at 165, so stirred it a bit more until it went down to 155 and closed the lid on my mash tun. Checked a half hour later and it was still at 155. Sparged 170 degrees. Krausen is gone, there are just a few small pockets of bubbles spread out over the top.

It's been fermenting at 68 degrees.

With mashing at 155, you might not get it to ferment too much more. I would be happy if it got to 1.022ish.

wait, your mash started at 155 and increased 10 degrees in 30 minutes? Is this a direct fired mash tun or an insulated cooler?

Because if its an insulated cooler, your mash started much higher than 155 since it cannot create heat...only lose it, with a direct fire or similar recirculated system that adds heat.

I could see a 165F mash stopping really really high on the final gravity.

I use a 60 qt insulated cooler for my mash tun. I added the water, stirred the grains for a while, took a temp reading and it read 155. Then took another reading half hour later and it shot up 10 degrees. Either I didn't mix well enough, I misread the temp, or what my friend thinks is that I superheated the water (whether or not that is the reason I have no idea).

I'd be willing to bed that it just wasn't mixed well enough. It's not uncommon for me to get a difference in 10 degrees or so when reading the mash temp prior to a vigorous stir.

Again, with that high of a mash temp, it might be done...but give it another week or two to see where it ends up.

OK, I'll give it a swirl and another week or so. Thanks guys!

I agree with what some of the other guys are saying - an insulated cooler can't add heat to the system - therefore it was really 165 degrees in there the whole time. Your 155 reading was a result of the heat not yet being distributed equally.

I would say mashing at 165 and finishing at 1.028 from a pretty high SG of 1.075 would be expected. If you swirl and give it more time you might drop a point or two but not much more.

Maybe read up on the amylase enzyme? It will help the yeast chew through the complex sugars leftover from the high temp mash.