Attenuation and Mash Temperature Question

OMG! Is my beer ruined?!?!?!

So I brewed Orfy's Mild Mannered Ale and my FG is higher than I'm used to @ 1.015 temp corrected. Here's the specs...

6 lbs Pale Malt, Maris Otter (3.0 SRM)
8.0 oz Caramel/Crystal Malt - 40L (40.0 SRM)
8.0 oz Caramel/Crystal Malt - 90L (90.0 SRM)
4.0 oz Chocolate Malt (350.0 SRM)

Mashed at 158dF for 60 min
OG 1.037
used rehydrated SafAle S-04 per directions on package
fermented at 67df for 14 days

racked to keg and took FG sample @ 1.015 for an apparent attenuation of 58%

Now, I have been getting apparent attenuation of 68% to as high as 74% with S-04, but that's with a mash temp of 152df to 154dF. I've never mashed at 158dF and not sure if 1.015 from 1.037 is what I should expect or if it should have gone lower.

It taste fine and landed at 3% ABV so I'm not too concerned, but wanted some more information on mash affecting attenuation.

matt

The higher mash temperature did indeed produce fewer fermentables, hence lower attenuation. The Beta enzyme, which is responsible for producing easily fermented sugars, doesn't last very long at 158F.

Take a look a Palmer's HowtoBrew.com, chapter 14 on mashing.

I figured that was it.

Time to start some test 1G batches to see attenuation over the mash temp scale.

Mine was 1.038 OG and FG 1.014. I mashed at 157*F. It's a nice beer, I wouldn't change a thing if I did it over.

mmb said:

I figured that was it.
Time to start some test 1G batches to see attenuation over the mash temp scale.

Click to expand...

Have you checked out Kaiser's website? He has a lot of really useful info on things like mash temp, pH, etc. where he has done the controlled experiments and written up the results. It's a great resource.

http://braukaiser.com/wiki/index.php?title=Limit_of_attenuation_experiment#Temperature_experiments