Managing Tannins as a Beer Character (Part II of II)

375px-Tannic_acid.svgAs mentioned in the first part of this article, there are a few beers that might benefit from just a hint of astringency. Usually, the slight puckering sensation will offset or complement another character in the beer. (And, of course, we all know that noticeable astringency in most beers is going to be unwanted.) There are a couple ways you can get just a hint of astringency in your beer, if you want it.

Tannins are water soluble. They are more soluble in high pH solutions than low. And, like most water soluble molecules, they are more soluble in hot water than cold. Let’s first review what happens when you use continuous sparging with 170 °F (77 °C) water. In other words, if you sparge in the normal way meant to minimize tannin extraction. [Read more…]

Managing Tannins as a Beer Character (Part I of II)


Tannic acid, the molecule that gives its name to the class of polyphenols called tannins.

Tannins are a class of molecules found in plants. At high doses, tannins are unpalatable to animals (including humans) and are most highly concentrated in the parts of plants that need the most protection. Some types of tannins are found in barley seed, and hence are present in malt. Other tannins are found in hops. A small amount of tannins are extracted in the mash and in the boil. Some react with proteins and drop out of the brewing stream, but some do carry over into finished beer — and brewing scientists have found that a beer completely devoid of tannins does not taste right. However, as all brewers know, an excess of tannins leads to a harsh astringency that is unpleasant. So, most brewers strive to minimize the amount of tannins extracted in their beers. [Read more…]

Tannins in the Boil


Tannic acid, a polyphenolic molecule used for tanning hides.

As I mentioned in the article on tannins in the mash, most of the tannins in your beer come from malt and are extracted during the mash. The major procedural thing you can do to avoid extracting excessive amounts of tannins is not to oversparge — do not continue collecting wort when the pH rises above 5.8. (This assumes your mash is at 170 °F (77 °C) at the end of wort collection.) If you don’t have a pH meter, the cutoff point for wort collection usually coincides with the specific gravity of the final runnings dropping to 2–3 °Plato (SG 1.008–1.012). You can also cool down a sample of your final runnings and taste them. You will feel the astringency increasing near the end of wort collection. (Astringency is a mouthfeel, not a taste.)

Hops also contribute tannins to your beer. However, if your sweet wort — the wort you collected from your lauter tun, not yet hopped — is OK, you really don’t have to worry further much about tannins. And this is good, since your only real way of controlling hop-derived tannins is to change the amount of hops you use.

Before we go on, recall that tannins are water soluble. Anytime tannic plant material is in an aqueous environment, tannins are dissolving into the liquid. Heat, pH and time are the major variables in tannin extraction. In the mash, the combination of temperatures 170 °F (77 °C) and over, coupled with a pH of 5.8 or greater, leads to tannins being very soluble. However, those conditions are not an “off and on” switch. In a mash at 160 °F (71 °C) at a pH of 5.6, tannins would dissolving into the wort, only at a much lower rate. Finally, recall that tannins are always present in beer — they are only a problem if their concentration is high enough to cause astringency.

[Read more…]

Tannins in the Mash


Too much tannin your beer can give it an iced-tea like puckering character.

Tannins are polyphenols found in a wide variety of plants, distributed among various tissues. In a later article, I’ll discuss the basic chemistry of the tannins relevant to brewing. (The types of tannins that end up in beer from the malt are different from those that originate in the hops.) In this article, however, we’ll treat them as a group because they are all related chemically, the factors that affect them are the same, and the consequences if they get in your beer are the same. I’ll discuss tannins extracted in the mash today, and cover tannins in the boil over the weekend.

[Read more…]

Tannins for Brewers (The Basics)


Tannin powder. (Photo by Simon E. Eugster, via Wikipedia, under Creative Commons license.)

As brewers, we often hear about tannins and how they are bad for our beer. But what are tannins? Where do they come from and how do they affect our beer? In this article, I’ll give an overview of tannins and their role in brewing. In a second article, I’ll discuss the nitty-gritty details of how tannins enter the brewing stream, and how to influence the rate at which they do in your home brewery. In a third article, I’ll discuss a little of bit of the chemistry of specific tannins that come from barley malt, hops and oak barrels.

[Read more…]