Mashing at 140 degrees Fahrenheit (60 degrees Celsius) can be done and has its benefits, but it is not a common practice in traditional beer brewing. This temperature range is considered to be on the lower end of the spectrum for mashing, and it is typically used in a technique called a “light body mash.”
The purpose of a light body mash is to optimize the activity of beta amylase, an enzyme responsible for breaking down long sugar chains into shorter, more fermentable ones. By mashing at a lower temperature, around 140-149 degrees Fahrenheit (60-65 degrees Celsius), you can encourage the production of these fermentable sugars and minimize the formation of unfermentable dextrins.
The activity of beta amylase is highest within this temperature range, resulting in a higher yeast attenuation rate and a lower final gravity for the beer. This means that more of the sugars in the mash will be converted into alcohol during fermentation, resulting in a drier, more crisp beer.
However, it is important to note that mashing at this temperature range can also present some challenges. The lower temperature may not fully activate other enzymes in the mash, such as alpha amylase, which is responsible for breaking down complex starches into simpler sugars. This can result in a less efficient conversion of starches into fermentable sugars, potentially leading to a lower overall malt extraction and a less full-bodied beer.
Additionally, mashing at lower temperatures can also affect the balance of flavors in the final beer. Since the fermentation process is driven by the yeast consuming sugars and producing alcohol and CO2, a higher concentration of fermentable sugars can result in a drier beer with less residual sweetness. This may be desirable for certain beer styles, such as light lagers or pale ales, but may not be suitable for others that require a fuller body and more residual sweetness, such as stouts or bocks.
In my personal experience as a brewer, I have experimented with mashing at various temperatures, including the lower end of the spectrum. I have found that mashing at 140 degrees Fahrenheit (60 degrees Celsius) can indeed result in a beer with a lighter body and a drier finish. This can be particularly beneficial when brewing beers that are meant to be refreshing and easy to drink, such as session IPAs or light lagers.
However, it is important to approach mashing at this temperature range with caution and consider the specific beer style and desired flavor profile. It may be necessary to make adjustments in other aspects of the brewing process, such as using a higher percentage of specialty malts or adjusting the hop schedule, to ensure a well-balanced beer.
While mashing at 140 degrees Fahrenheit (60 degrees Celsius) is not a common practice in traditional brewing, it can be a useful technique for achieving specific flavor profiles in certain beer styles. However, it requires careful consideration and experimentation to ensure that the desired results are achieved without compromising the overall quality of the beer.