Many years back brewers used to incorporate multiple mash steps into their brewing. Because malt was not as highly modified as it is today. In modern brewing, it’s also common for us to just use two mash steps.
The first thing to understand is that mash temperature can have many different effects. Essentially it can adjust the body, taste, and mouthfeel of the beer. Temperature determines how the sugars are broken down in your mash that will dictate what is ready for your yeast to eat.
For more special advice check our Homebrewing techniques on specific gravity.
Alpha and Beta Amylase
In modern single infusion brewing there are two main enzymes. These are known as alpha and beta amylase.
Alpha amylase is most active betwwen 154 to 162 F. It will convert the sugars held in your grain into sugars that are not very fermentable by the yeast. Whis will actually add more body to your beer. But iw will also mean that much of this sugar will not be eaten by the yeast. It will simply stay within your brew.
Besta amylase is most active between 131 to 150 F. Beta creates very fermentable sugars that can easily be eaten by yeast and thus turned into alcohol. Mash on a lower scale of this range will lack body. More than one temperature step in this range can be used to create variation of flavor. Which in turn can create more complexity.
Hops and Malt
A common mash schedule these days is the 149 F/167 F. The effect of this is middle of the road conversion. This is a pretty common schedule for hoppy beers that rely moreon the flavor of your hop additions than malts. These are otherwise known as hop forward beer.
Beers that demand more complexity because they are malt forward tend to have more mash steps. We laso have what is known as acid rest. This used to be used to lower the PH of the mash. Triuble is that it could actually take some hours to do. Its been mosly abandoned by modern brewers.
Beta Glucana rest can be used to protect your sparge against a contents that can get gummy and cause a stuck sparge. This rest can lead to a reduced level of clarity in your end brew.