Mouthfeel and Body: Variables and Control on a Homebrew scale
Having volunteered as a steward at a recent local homebrew competition, I was able to refresh my pallet on a variety of common flaws in beer, especially homebrew. Of all the flaws I tasted and cataloged in my brain for future reference (my next aspiration is to become a BJCP certified judge), one flaw stood out because, until recently, it was occurring in my very own homebrew.
That flaw is mouth feel and body; many of the beers I was making had wonderful color and aroma, and some flavor, but were very thin bodied. After making several adjustments to my homebrew system, I finally figured out what the problem was. It is a very common and easy thing to overlook for many home brewers. A beer’s body and, consequently, major aspects of flavor are derived from two main factors in the brewing process:
•Levels of unfermentable sugars in the wort
Specialty malts such as chocolate, biscuit, and toasted or roasted malts will directly assert flavor to the wort simply depending on the proportions used in the grist. The more of a certain type of specialty malt you use in a brew, the more that flavor will come to dominate.
The other main factor is purely a result of brewing technique; unfermentable sugars are left alone by the yeast during fermentation and are, consequently, left in the beer to contribute flavor, body, and sweetness. But how does one control this? First you must ask yourself if the beer you are brewing requires you have body in the first place. As a general rule, light beers and pilsners actually dictate having very little body by the style of beer. Others, however, do require quite a bit of body, and it is these beers that will require control during brewing.
Long chain sugars are cut from the amylose and amylopectin chains (starch) in the malt by alpha amylase, which are then converted into smaller sugars by beta. So if we can optimize a mash temperature and pH for alpha amylase, we can produce a beer with bolder body and flavor for styles like German lagers and English ales (to name a few). As it turns out, alpha amylase’s activity is toward the upper end of the saccharification range; meaning that mashing temperatures between 155-159F will produce bold enough body to compensate for any issues.
Another critical factor in this process is alpha and beta amylase deactivation; you have performed your mash and now you have to sparge, but if you’re mash temp is still between 150-160, the enzymes are still going to be doing their thing. They will eventually become deactivated by your sparge water if your lauter tun is insulated enough and your sparge water is hot enough (~175F). However, if you don’t properly account for those factors you can have continued diastatic activity in your grain bed and wort which contributes to thinner body. If you think this may be a problem for you, you can either directly heat your mash water to 170F prior to sparging for 5 minutes OR you can add a portion of boiling water to your mash tun or lauter tun to bring your mash up to temp. If you think there may still be a problem, low attenuating yeasts can be used to leave behind sugars after fermentation that will also leave body in your finished beer.
-Cheers to Bigger Bodied Beers