Extending mash times for better attenuation...

[Al-Loves-Wine]

So I was reading on HBT that a fair amount of people do 90 min opposed to 60 to get a better conversion. I make a pilsner that I always do 90 on because I'm just following instructions, and it dries up a fair bit better around 1.005ish, and is really crisp. Where other lagers I'm only doing 60 and coming in at 1.010 give or take a few points.

Has anybody else tried this as a side by side test with 60 and 90 min mash, and seen similar results in how dry your beer gets? I just did an IIPA close to Pliny the Elder with Amarillo instead of Simcoe. It got fairly dry at 1.015 from 1.075, but that seems to be common with most of my ales when I should be getting closer to the 1.010 mark. So this weekend I plan on doing another IIPA with an identical grain bill and different hops to see if I get better conversion and a drier beer.

[Chris Craig]

The longer mash will allow the enzymes more time to break down complex sugar chains making it easier for the yeast to consume, so yes.  A longer mash will help dry the beer out more.  A lower rest temperature will help that even further.  I make IIPAs with a 149ºF rest for 90 minutes because I like 'em dry.

[jamie_savoie]

I never did a side by side test but when I brew beers that need to be really dry I mash at low temp and extend the mash to 90 or even 120 min.  When I mash @ 148-149 I do 90 min rest, and when @ 145-147 I rest for 120 min. Sometimes I also start my mash at lunch and start the sparge after work which makes it 4-5h mash.  I strictly do this to save time when I brew on weekdays though. 

[Al-Loves-Wine]

Awesome! I'm gonna try that this weekend. I haven't brewed in a few weeks, and I'm starting to go through withdraw.

[pliny]

Length of mash is one thing but conversion is usually complete in 60 minutes. As stated above, the mash temp has alot more to do with it. Also the thickness of the mash will also play role in the attenuation. The thicker the mash, more attenuation. Maybe the latter is not a factor if you always mash in the same manner and assuming you pitched your yeast in the same manner.

[Waterlogged]

So there is no ill affect for doing a 4-5 hour mash?  We are running out of day light in the evaning so this may be a solution for us. 

[fakr]

first off, the type of yeast you use should have an impact on attenuation...

and second, you might want to consider dropping the grain bill back a little and compensating with some DME or corn sugar to dry things out a bit.

just saying....

[jamie_savoie]

So there is no ill affect for doing a 4-5 hour mash?  We are running out of day light in the evaning so this may be a solution for us.

no ill affect for me but I only do this when brewing something that needs to be bone dry.  I usually loose 10 degree F or less over 5h

[DandyMason]

Ive heard of people mashing, collecting all the wort and then boiling later on in the day...

I guess a mashout would stop it from getting too dry