What is a good diastatic power?

Answered by Randall Whitlock

A good diastatic power is essential for a successful starch conversion during the process. Diastatic power (DP) is a measure of the enzyme activity in , specifically the ability of the enzymes to break down starches into fermentable sugars. The higher the DP, the more efficient the conversion of starches into sugars, which is crucial for the fermentation process.

To determine what is considered a good diastatic power, it is important to understand the range of values typically seen in different types of malt. Diastatic power is measured in degrees Lintner (°L), and different malts have different levels of enzymatic activity. Generally, a diastatic power of 30°L or higher is considered good for most brewing purposes.

However, it is important to note that the desired diastatic power may vary depending on the specific style or recipe. For example, some styles, such as highly adjunct-based beers or beers with a high percentage of unmalted grains, may require a higher diastatic power to ensure a complete conversion of starches.

In my experience as a brewer, I have found that aiming for a diastatic power of around 70°L is often a good target for most beer styles. This ensures a robust enzymatic activity that can effectively convert the starches in the malt into fermentable sugars.

There are several ways to increase the diastatic power in a recipe. One option is to use malt varieties with higher diastatic power, such as Pilsner malt or pale malt. These malts typically have a higher enzyme content and can contribute to a higher overall diastatic power in the grain bill.

Another approach is to use a combination of malts with different diastatic powers to achieve the desired average. For example, if a recipe calls for Munich malt with a diastatic power of 25°L, which is relatively low, you could consider replacing a portion of the Munich malt with Vienna malt, which has a higher diastatic power of around 50°L. This substitution would increase the average diastatic power of the grain bill and improve the chances of a successful starch conversion.

Additionally, using malt that has been properly stored and handled is crucial for preserving its diastatic power. Malt that has been exposed to high temperatures or moisture can have reduced enzyme activity, leading to a lower diastatic power. Therefore, it is important to store malt in a cool, dry place to maintain its enzymatic potential.

A good diastatic power is typically considered to be around 30°L or higher. However, the desired diastatic power may vary depending on the specific beer style or recipe. Aim for an average diastatic power of around 70°L to ensure a successful starch conversion during the brewing process. Experimenting with different malt varieties and properly storing malt are key factors in achieving the desired diastatic power in your beer.