To get the enzymes to act on the starch, we mix the malt in a medium of the correct pH and temperature. Since the enzymes have different effective temperatures and pH levels, home brewers generally compromise at a temperature of 66 c and a pH 5.3, though in fact the pH doesn't have a large bearing on the outcome.

It is possible to control the ultimate quality if the beer at this stage by careful temperature control - nearer 70 c for a heavier lower alcohol beer, nearer 63 c for a light higher alcohol beer.

{At 65 c Beta Amylase stops working after 40-60 minutes, and at 67 c Alpha Amylase stops working after 2 hours}.

The malty extract that pours out at the end of the mash is called Wort.