Maillard reactions. As I write those words, I picture a beautiful steak with a tasty charred crust, courtesy of the Maillard reaction (or MR from now on). As I wrote in my previous article about Diacetyl (here), MR’s are usually responsible for the tasty browning that occurs when heat is applied to food. They are important to us beer enthusiasts because they are also responsible for much of the changing flavor we get when our favorite craft brews age.

A MR is a multi-stage reaction that occurs between a sugar and an amino acid. A whole host of compounds can be formed as a result of MR’s, especially when you think of the number of different combinations of sugars and amino acids that are possible. Increased heat, increased acidity, and increased humidity can all result in increases in the rate at which the MR occurs.

There’s a very interesting correlation between MR’s and beer cellaring. It has been shown that some of the very beers that are best suited for the cellar - high alcohol, dark beers - are also the ones most prone to MR’s. It seems the typical techniques used to brew these kind of beers result in the formation of MR “intermediate” compounds in far greater numbers then in other kinds of beer. As a beer ages, these compounds will react with other substances in the beer to produce the flavors and colors that are associated with the MR.

And what flavors they can bring! We can now associate such flavors as sweet, burnt, caramel, wine, Madeira, and brandy with MR’s occurring in your beer. There are even more flavors that can’t be directly tasted, but seem to lend a complexity to the beer that would be missed if they weren’t there.

Does your aged beer seem darker? It probably is, and one cause of it are brown pigmentation molecules formed by the MR.

There is a dark side to the MR, however. It’s a really fine line between added complexity and staleness in an aged beer. Virtually all of the flavors I’ve discussed so far can also contribute to the stale taste of a beer if allowed to progress to far. Fortunately, there is something we can do about this. Remember when I said that increased heat, acidity, and humidity leads to an increase in MR’s? The converse is also true. You may not be able to adjust the acidity or humidity of your beer, but you sure as hell can change the temperature it is kept at.

If you have a beer getting near, at, or even a little beyond it’s peak, I would suggest moving it from it’s normal cellared area to a refrigerator. The colder temps will put the breaks on MR’s, and give you a little longer to enjoy your brew. If you’re able to, you might also want to play around with the normal temps you’re cellaring your beer at in an effort to optimize the MR to your advantage.

That’s all for now, may all your beer age gracefully!

Jason

jason@brewbasement.com