Originally Posted by mrwizard0
Isn't this comparing two different things? The same grist mashed at 149 for 60 min should attenuate lower than one mashed at 154 for 60 minutes.
Yes, this is an apples oranges comparison. Temperature effects attenuation by favoring one enzyme over another. Lower temps favor beta amylase which creates more strait maltose, while alpha amylase creates more dextrins and less fermentable sugars. While a lower temp like 145 FAVORS beta amylase, alpha amylase still does some work. Enzyme activity is not an on off switch, but a bell curve. A mash at 145-155 has BOTH enzymes active so mashing longer will ALWAYS result in greater fermentability because beta amylase will have a chance to "catch up" even in a warmer mash. This however is not the easiest way to affect fermentability. More commonly brewers simply vary the temperature, and keep the time consistent...
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