high mash temp and low attenuation

[mwill07]

So I was purposefully trying to make a low-alcohol beer - lower gravity than I normally brew, but then to make it not seem thin I added a good amount of crystal and caramunich for extra body and I mashed fairly high. I ended up (predictably) with poor attenuation - is the beer done, or is there more to go? (I know, wait a day and measure gravity again, rouse the yeast,, go back in time and do a FFT, etc).

Recipe:
Marris Otter: 87%
Crystal 40: 9%
Caramunich: 3%
Mash temp: 158 F
Yeast: Safale US-04 (rehydrated and pitched into oxygenated wort)
ferment temp: 64 F
fermentation: 1 week


OG: 1.043
current gravity: 1.016

ABV: 3.5%
Attenuation: 62%

this is the highest I've ever mashed and am therefore unsure if this attenuation is consistent with others results.

Thanks.

 

[mwill07]

Ok, so I found this article http://brulosophy.com/2015/10/12/the-mash-high-vs-low-temperature-exbeeriment-results/.

They compared high vs low mash temps for a recipe similar to mine - similar grain bill, yeast, and temps. My results tracked very closely to their high-temp variant, so it appears I am within range.

Looks like all that's left is for me to RDWHAHB.

 

[brewbama]

I believe the higher temp produced less fermentable sugars than a lower temp. Therefore the yeast processed all the fermentable sugars and left you with a sweeter, higher FG.

 

[govner1]

I think you'd be better off adjusting your recipe (base grains) to get the ABV you're after. It should yield you a better balanced beer and be more predictable than trying to get there playing with your mash temp.
There are many "session" recipes out there that can give you a starting point.