Mashing/Conversion Time Question

[inkubuzz]

Hi guys, I usually Mash between 60 to 90 minutes, but recently I bought "the Craft of Stone Brewing Co." book, which has some recipes of their beers for homebrewing (very cool stuff) but in some recipes it says: Conversion temperature 157°F (10 minutes) and a mash out at 165°


10 minutes!!!!! isnt that to short???

For example:

Stone Levitation Ale

85% crushed North Ameican 2-rowa Pale malt
9% crushed 75 L crystal malt
5.2% crushed 150 L crystal malt
0,8% crushed black malt
Conversion temeprture 157°F (10 Minutes)
Mash Put 165°F

0.108 lb/bbl Columbis Hops (12.9% aa) 90 minutes
0.35 lb/bbl Amarillo Hops (8.5% aa) 10 minutes
0.35 lb/bbl Crystal hops (3.5% aa) 0 minutes
0.10 lb/bbl Simcoe hops (13.0% aa) 0 minutes

White Labs WLP007 Dry English ale Yeast or WLP002 English Ale Yeast

 

[Yooper]

It's not too short, IF you have conversion by then. At higher temperatures, conversion happens quickly. I've never checked it earlier than 20 minutes, but I have had conversion (as shown by iodine test) in 20 minutes with a 156 degree mash.

Most often I still do a 60 minute mash, and skip the testing.

 

[pjj2ba]

Temperature has a dramatic affect on conversion rates. If you are at the optimum it can be very fast indeed. I did a quick look around for some scientific articles on amylase activity and found a bunch on amylases from other organisms (like bacteria) so the actual temperatures varied, What I could see was that a drop of 20 F from the optimal temp. for these amylases can lead to up to a 50 percent reduction in activity rate.

 

[sonex]

mash conversion time really increases as you lower the temp down under 150f. Thats why with many beers that are very light bodied such as pilsners the recommended mash time to be safe increases to 90 minutes. I have mashed at 147f many times and I always let it go for 90 min to be safe.