Changing mash temp doesn't change predicted FG or ABV

[Tom O]

I've been brewing and using Brewers Friend for about 5 years with very good results (at times award winning) and 75 brew sessions. When I mash at a higher temp, I expect less fermentable sugars, more non-fermentable, a higher FG and lower ABV. BF doesn't appear to estimate that. If I input a typical recipe to mash at 152 degrees F, I get the predicted FG and ABV. If I edit that recipe and change the mash temp to 158, the FG and ABV doesn't change. Is there something that I'm missing?

 

[Yooper]

I've been brewing and using Brewers Friend for about 5 years with very good results (at times award winning) and 75 brew sessions. When I mash at a higher temp, I expect less fermentable sugars, more non-fermentable, a higher FG and lower ABV. BF doesn't appear to estimate that. If I input a typical recipe to mash at 152 degrees F, I get the predicted FG and ABV. If I edit that recipe and change the mash temp to 158, the FG and ABV doesn't change. Is there something that I'm missing?

While it's true that sometimes you get a higher FG with a higher mash temp, it doesn't always predictably do that or a certain amount. It still depends much more on the ingredients themselves, and the yeast strain chosen. If your experience with that recipe, that mash temp, and that yeast strain is so that it will keep the FG higher, then you can adjust the attenuation of the yeast (in the yeast section of the Recipe Builder) to reflect your actual experience.

 

[Josh Hughes]

Especially if you use the same yeast a lot for predictability and same procedures etc. You can probably adjust that and efficiency to match what you get most every time. When I started doing that the calculator was pretty spot on

 

[Tom O]

Well, true and tweaking the attenuation or efficiency is a potential hack. But it's an absolute that a higher mash temp, (especially 158 - 160 or higher) will significantly favor alpha amylase and therefore non-fermentable sugars. It would be helpful if BF could estimate.

 

[Craigerrr]

The software I use changes the potential ABV based on mash temperature, so I agree with @Tom O
with everyrhing else being equal, the software should adjust potential ABV, after all we mash at different temperatures for a reason

 

[Dave Y]

The B/F calculations are more like guidelines than actual hard and fast numbers. Think ‘Pirate Code’.