Wednesday, November 30, 2011

On the Importance of Barley, Part One

We've spent a whole lot of time here on MBR talking about hops. A whole lot of time. We've talked about growing them, we've talked about steeping them, we've talked about hop efficiencies. We've endlessly debated my love for West Coast IPAs and hop-bombs and everyone else's disdain for them.

Maybe it's time we spent some time talking about malt.

There are a whole world of questions that I'm not sure MBR has ever discussed about malt. What is "malt" being foremost among them. Let alone how malt is smoked, why "chocolate malt" doesn't have any chocolate in it, differentiating between Munich and Vienna malt, and who, or what, Maris Otter is (though we know who Roger Maris and Otter Creek are). Though, strangely, we have discussed 6-row barley and the relative merits of 6-row vs. 2-row barley.

But malt is a pretty big component of beer. And, one of the world leaders in malting barley is located just up Highway 151 in Chilton, WI: Briess Malt & Ingredients Co.

So, it's probably best to start at what is Malt, and more precisely, what is barley since, as we'll see, "malt" is short-hand for (usually) "malted barley".

I'm not sure we're going to finish answering that question today, but it's best to back up a minute and look at the brewing process itself because the science of barley is the science of brewing.

1. Barley is picked from the field and aggregated at a centralized grain storage and distribution facility.

2. Brewing quality barley is transported to a maltster where it is malted. The resulting product is generally called "malt". Grains other than barley can be malted (wheat, for example), though most brewing adjuncts (things other than barley) are unmalted additions to the mash (see below).

3. Malt is shipped to and stored at the brewery where the actual brewing process will begin.

4. The malt is put into a hopper and crushed in a grain mill. Also called milling.

5. The crushed malt is sent to a mash tun where water at a specific temperature is added and the malt is steeped for a period of time (the temperature may or may not be altered during the steep). This is the mashing process. The liquid (called "wort") is drained from the mashtun into either a lautertun (in which case the grains are also transferred) or a boil kettle.

6. The remaining grains are rinsed off with more water and that liquid is also added to the boil kettle. This is the lautering process.

7. The wort is boiled for about 60 minutes, during which hops are added at various points (often at the 60 minute mark, the 30 minute mark, and when the heat is turned off). This is the boil.

8. The wort is then cooled down to approximately 65 degrees (for an ale), and transferred to a fermentation tank where yeast and oxygen is added.

9. After a few days you have beer, which, in a commercial brewery, is sent to a bright tank/tax tank to carbonate and settle out, then on to the bottling/kegging line and out the door.

From start to finish, the science of barley and malting affects the final product in your bottle. So, what is this all-important grain, barley? I'm glad you asked. Barley's scientific genus is Hordeum, with two species that are relevant to beer: Hordeum Vulgare (6-row) and Hordeum Distichon (2-row). It is an annual grass. There are endless cultivars as brewers and maltsters are constantly genetically training barley for their specific purpose.

Barley was one of the first grains human civilization cultivated starting in approximately 10,000 BC. Yes, 12,000 years ago. Today, it is the number 4 cereal grain in the world with over 152 billion tonnes (metric tons) produced globally each year. It is used largely as a feed crop for animals, as it was when it was first cultivated, but human consumption accounts for a significant percentage of the production. In the United States about 25 percent of the annual production is sent to malting.

Barley is grown in temperate areas and is known as a relatively finicky grain. For example, while it is moderately heat tolerant, it does not tolerate cold at all, and most brewing varietals do not tolerate long droughts. Moreover, it is susceptible to a number of crop diseases. So, much like the problems in corn, barley monoculture (growing one variety of barley) can have drastic effects when disease hits.

The stem (stalk) of barley can vary from 1 to 4 feet and typically have 5 to 7 leaf-like nodes below the spike. The spike consists of spikelets attached to the central stem called a rachis. Three spikelets develop at each node. In six-row barley a flower/seed form at each spikelet; in two-row barley on the center spikelet forms a flower/seed (see images a, and b, respectively, below). 2-row seeds are much bigger than 6-row seeds and have a higher ratio of nutrients (carbohydrates and protein) to non-starch material (husk).

It is the seed that maltsters and brewers are most interested in. The seed itself is comprised of a protective husk on the outside,  a non-starch cellular membrane called "aleurone", then the  endosperm that consists of carbohydrates and protein, and an embryo. "The total number of cells in the kernel endosperm reaches over 280,000, as compared to 117,500 in wheat and 180,000 in rice. This is the reason why barley kernels contain more cell wall material and, consequently, more of its main component, beta-glucans, than those other cereals." [cite]

A mature seed contains approximately 35% moisture (a white milky substance, typically) and is allowed to dry in the field until its moisture reaches approximately 20%. This is done for a variety of reasons, the primary of which is that a seed that has a lot of water is very brittle and tends to rupture and split - something that the maltsters don't like because it reduces the ability of seed to continue to germinate (we'll talk about this later).

You can see how decisions in the field directly affect barley quality. Thus, barley from one farm, whose micro-climate may be dryer (slightly longer germination and faster drying conditions), may be very different from barley from another farm whose micro-climate may be more moist. And we haven't even discussed differences in the hundreds of barley varietals that the farmers choose to grow. Each varietal has slightly different growing conditions and carbohydrate and protein mixes. These differences can have profound impacts when the barley is malted.

During "threshing", the seed is removed from the stalk and the "chaff" (the feathery material and other non-seed stuff). After the seed is removed from the stalk and chaff it is dried to below 12% moisture for storage and transportation. Because of the precise dry-storage conditions required for barley, the seed is transported from the farm to a central storage facility. After this central drying and storage, the seed is often then aggregated in larger centralized silos and then shipped off to maltsters.


You can see how the decision to aggregate and mix, commodify, barley is both a blessing and a curse. In one respect it evens out the minor differences between farms in order to fulfill large orders placed by maltsters and brewers. On the other hand, though, it removes the uniqueness that one farm's barley has with respect to another. In wine, with grapes, we call this uniqueness "terroir" and it is celebrated and valued. It is only recently, within the past 2 years, that this value is being leveraged in the brewing industry with Lakefront, Rogue, and Sierra Nevada leading the way with beer produced with non-commodified barley (Local Acre, Chateau Rogue, and Sierra Nevada Estate, respectively).

If you refer back to the steps listed above, we have just completed (in a very summary way mind you) step one. In future articles we'll talk about the malting process and how that works.

No comments:

Post a Comment

Note: Only a member of this blog may post a comment.