The Methods of Mashing
Single Temperature Infusion
This method is the simplest, and does the job for most beer styles. All of the crushed malt is mixed (infused) with hot water to achieve a mash temperature of 150-158F, depending on the style of beer being made. The infusion water temperature varies with the water-to-grain ratio being used for the mash, but generally the initial "strike water" temperature is 10-15·°F above the target mash temperature. The equation is listed below in the section, "Calculations for Infusions." The mash should be held at the saccharification temperature for about an hour, hopefully losing no more than a couple degrees. The mash temperature can be maintained by placing the mash tun in a warm oven, an insulated box or by adding heat from the stove. The goal is to achieve a steady temperature.
One of the best ways to maintain the mash temperature is to use an ice chest or picnic cooler as the mash tun. This is the method I recommend throughout the rest of this section of the book. Instructions for building a picnic cooler mash/lauter tun are given in Appendix D.
If the initial infusion of water does not achieve the desired temperature, you can add more hot water according to the infusion calculations.