This week I take a look at when you should apply different mash techniques to achieve a particular style or effect in your finished beer.
Mash Temperatures and Body
The first technique we will look at is simply adjusting your mash temperature to achieve a particular effect. For a typical mash we can take advantage of the fact that alpha and beta enzymes act in different temperature ranges (as explained here) to adjust the perceived body of our beer.
Choosing a higher temperature for our mash, around 156-158 F (69-70 C) will result more unfermentable starches, lower attenuation and a full bodied beer. Choosing a low temperature around 140-149 F (60-65 C) will produce more fermentables, higher attenuation and a lighter bodied beer. A mid range mash around 153 F (67 C) will give a medium bodied beer.
The only question is which is most appropriate to the style of beer you are brewing? A Stout, Robust Porter or even many English and Scottish ales benefit from a full bodied mash that gives them a complex finish. However many Continental styles, particularly lagers, should use a lighter bodied mash to promote full fermentation and a clean finish. American styles vary widely but some IPAs might be better with a clean dry light body finish, while others like Hazy and Fruity IPAs could benefit from additional body and complexity.
There is also another type of mash called a Lager style mash, which is a two step mash hitting both the low end of the range at 145 F (63 C) and another step at 159 F (70 C). This mash promotes a full conversion of sugars by activating both alpha and beta enzymes, and results in an even drier, lower body than a typical light body mash. It is most often associated with Continental lagers like many German styles, and Pilsners as it gives a slightly malty but very clean finish to the beer.
Mash pH and Body
Controlling mash pH is very important for all grain brewers as it enhances the flavor, brightness and long term stability of the beer. Ideally you want to adjust the pH at the beginning of the mash to get it somewhere in the 5.2-5.6 range. I’ve written extensively on how to manage your mash pH with small acid adjustments, and there are features built into BeerSmith to help you adjust your mash pH. I’ve also written an excellent article on how to best time your mash acid additions.
While often overlooked, you can also vary the pH of your mash to enhance or reduce the body of your beer. While you always want to adjust your mash pH to remain in the 5.2-5.6 range, a higher mash pH near the 5.6 range will affect enzyme activity resulting in a fuller body beer. Conversely a low mash pH in the 5.2 range will lighten the body of your beer.
So in addition to temperature you can make small adjustments to your mash pH using something like lactic acid to further enhance the body of your beer.
Steeping or Sparging Dark Grains
Another great technique to use with darker beers is to remove many of your dark grains from the extended mash and instead add them at the very end of the mash or during your sparge. Dark grains contain harsh tannins and acids that can create a burnt coffee or other harsh flavors if mashed for an extended period. I liken the effect to percolating your coffee for way too long in a traditional percolator.
Since roasted grains contribute relatively few fermentables to the mash, you can bypass the mash entirely with these grains. The original method used here was to make a separate tea with the dark grains, but most home brewers have figured out that a simpler method is to just add the dark grains for 10 minutes end of the mash if using a BIAB technique, or simply sprinkle them over the mash tun right before sparging if using a traditional sparge step.
I covered this technique more extensively here as well as how to do this in BeerSmith in this article. The main advantage of using this technique is that it reduces the harshness from the dark malts so it is appropriate in many dark beer styles like brown ales, milder Porters, Bock, and sweeter Stout styles where you want a dark roasted flavor without the hard edgy tannic finish. However, in something like a Dry Irish Stout or Robust Porter this technique is less appropriate as both of those rely on strong roast grains for their flavor profile.
Mash Hopping
Though an old technique, mash hopping has enjoyed a small resurgence not for developing bitterness in a beer but for providing some gains in the long term stability of the beer, and also to enhance thiols to develop fruity tropical flavors in IPAs. Recent research has shown that adding some hops to the mash can help to lower the presence of certain metals like iron in beer that can hurt its long term stability. This would primarily be a benefit for beers that you intend to store for an extended period or for beers that are commercially packaged and may remain on the shelf for a long time.
Research by others including Yakima valley has found that adding hops can aid in developing free thiols in the beer which when combined with certain boil, whirlpool and dry hops can aid in developing tropical fruity flavors in styles like Hazy or New England IPAs. If you want to learn more about mash hops for either method you can read my article here which has additional links to reference materials.
I hope you enjoyed this weeks summary on various mash techniques and how to use them. Thanks for joining me on the BeerSmith Home Brewing Blog. If you want to take the guesswork out of brewing, please try my BeerSmith recipe software from BeerSmith.com. Be sure to sign up for my newsletter or my podcast (also on itunes and youtube) for more great tips on homebrewing.