This is the second half of an article that was posted yesterday. 

A step mash for a reasonably dry beer — drier than could be made with a single infusion mash.

After the beta amylase rest (140–145 °F/60–63 °C), and the temperature ramp up into the saccharification range (148–162 °F/64–72 °C), the rest of wort production is almost identical to a single infusion mash. One difference is that you can choose a slightly higher temperature for your main mash rest. If you were brewing a dry beer and using a single infusion mash, you would likely rest in the 148–151 °F (64–66 °C) range. If you were brewing a somewhat drier beer, you could in the 152–154 °F (67–68 °C) range after the beta amylase rest. Because you’ve already rested at lower temperatures (favoring beta amylase), your main rest can be slightly higher, favoring alpha amylase a bit more, comparatively.

Both alpha and beta amylase will be active at both rests, just to varying degrees. In the beta amylase range, the activity of alpha amylase is still substantial (albeit less than it will be at the higher temperature of the saccharification rest). In the saccharification rest, beta amylase activity continues, although it will decline fairly quickly over time. Still — since it has already been working for a period of time at the lower rest — there is less substrate for it to deal with.  [Read more…]

A step mash for brewing a dry beer. A 15-minute rest at 140 °F (60 °C) is followed by heating the mash to a roughly 45-minute rest at 152 °F (64 °C). Finally, the mash is heated to 170 °F (77 °C) for a mash out. (Click to Enlarge.)

Sometimes the simplest approach is the best. When brewing with fully-modified malts — as most malts are these days — a single infusion mash is almost always your best bet. The maltster has taken care of many of the issues (gums, proteins) that would have required a step mash. In most cases, performing a step mash is at best a waste of time. At worst, it can decrease the quality of your foam. And, by varying the mash temperature of your single infusion mash, you can make wort with varying degrees of fermentability. For most styles of beer, this range of fermentability is adequate.

However, there are some times when a step mash is just the thing. If you are brewing with undermodified malt, a step mash is highly recommended. (If you single infusion mash, you may end up with too many proteins in your wort and gums (glucans) may make lautering difficult.) I’ll cover this approach in a later article on decoction mashing (a type of step mashing). [Read more…]