It seems like there's so much focus in the homebrewing community (or at least the American homebrewing community) placed around hops and to a lesser extent yeast, but you don't see nearly the same level of interest or fervor put into malt. I hope to change some minds with this post and get people more excited and educated on the malts they use in brewing by going over how to read a malt analysis report.
Two Row Isn't A Variety
When you look at most homebrew recipes, it's not uncommon for it to start out with something like "10lbs of 2-row" and this just makes me cringe. Would you consider it acceptable to state "1oz of aroma hops" or "some ale yeast"? Think of how different a recipe would be if you used 1oz of Citra vs Tett. Why do we have such disdain for the barley we use? How many varieties of barley can you even name? Most people would say "Maris Otter" and that would be about it. You might get the odd Halcyon or Optic, but that's rare. Most base malts end up being a blend of different varieties to help average out their traits over a given lot, but you can still get some flavor impact from one maltster's base to another. For instance, Riverbend says their base 6-row has a "slightly spicy, grassy flavor" while Valley Malt "may exhibit a faint strawberry or orange flavor". So, if at all possible, find out what variety of barley is being used or what mix is being used. Start to familiarize yourself with names and flavor aspects of different varieties of barley. If you can't get an idea of what barley you're using, at least try to find out where the barley is grown and if you're dealing with a spring barley or a winter barley. Much like Cascade hops grown in the Pacific Northwest aren't exactly like Cascade grown on the East Coast, so to is barley grown in different regions. The difference between using spring malt and winter malt, from the brewer's point of view, is basically winter barley varieties tend to have less protein and less enzymes than spring barley. Some other attributes associated with variety would be size or plumpness of the barley corn. Plumper corns (read: bigger barley) tend to have better extract potential and it's slightly easier to mill. Size tolerance (if listed) can give you some clue as to how varied your mix of base malt might be (if variety isn't listed), but also a hint as to what variations you might expect in milling and extract performance. Tighter size tolerance will typically have more predictable crush, but probably single variety or very few varieties were used. Looser size tolerance typically means a wider variety of barley used in the mix and (usually) less variation in other variables from season to season since the maltster is blending to even out malt characteristics.
The Hard Numbers
Now that we've discussed a bit about the barley and where it comes from, let's talk about what the maltster does with it and what that means to you, the brewer.
With the exception of the aforementioned Maris Otter, almost every other name of malt you're likely to see describes how it was processed and kilned by the maltster, rather than what variety of barley it is. One of the easiest attributes to identify and understand the impact of these processes is the color. Color (and flavor) develops during kilning as a result of Malliard reactions which darken the barley corn. The longer and hotter the kilning, the darker the color will be. In North America color is assessed on the Lovibond or Standard Research Method (SRM) scale. You can convert between the two by the formula
In Europe, the European Brewing Convention (EBC) is used which can be converted to or from North American measure by the following formula
On all scales, the lower the number, the lighter the kiln. Lighter colors generally imply sweet, hay, bread, or biscuity flavors while moving darker takes you through caramels, stone fruits, dark bread crust, on up into coffee, chocolate, charcoal notes with the darkest roasts.
Next thing on the list to consider is Moisture Content (MC). The lower the moisture content of malt, the less risk it faces from mold and mildew. 1.5% MC by weight or less is ideal and should store well with minimal flavor and aroma loss over time. No malt, with the exception of caramel malts, should really be considered acceptable if it's over 5% MC. Because of their natural tendency to be gooey, caramel malts can vary between 3-6% MC. This is normal, but it should be noted that the allowable storage time for these malts will still be lower than a base malt with 1.5% MC. When looking at the moisture content figure, you're not just getting an idea of the shelf life of the malt, but also the skill of the maltster. Lower numbers mean a better kilning process.
Figures surrounding extract are where things tend to get complicated. Simply put, these figures will describe what you can expect in terms of sugar extraction. Where it gets complicated is how this information gets conveyed to the brewer. In North America, it's typical to get two figures; fine grind or DBFG (dry basis, fine grind) and coarse grind or DBCG (dry basis, coarse grind). Both figures will be expressed as a percentage and both measurements are adjusted to 0% moisture content. Your fine grind percentage tells you the maximum possible yield for the malt. The idea is that you grind everything down to powder and anything that isn't converted is protein or husk. Coarse grind more closely resembles conditions in the average brewhouse. This percentage will give you a rough idea of what kind of extract you can expect.
Sometimes the difference between DBFG and DBCG is given instead of DBCG. This figure can be called extract difference or grind difference. In addition to allowing you to calculate DBCG from DBFG, this is also indirectly a measurement of how well the malt is modified and what kind of mash you should do with the malt. When grind difference is small, it's an indication that you can do a single infusion mash to get the most out of the malt. Larger grind differences mean you should probably to a step mash or decoction.
If you have a grasp on your system's brewhouse efficiency, you can even calculate out the gravity points you can expect to extract from the malt on your system. In North America, the extract per pound of malt, per gallon :
Which brings us to how Europeans measure extract. As to be expected, it's entirely different. You'll typically see Hot Water Extract (HWE) and Cold Water Extract (CWE) percentages given instead of grind percentages. HWE is given in 7M (coarse grind) and 2M (fine grind) which can be converted to DBCG and DBFG by dividing by 386. CWE is somewhat equivalent to grind difference in that it's a measurement of how well the malt is modified, but there's no direct conversion. Generally speaking 20-25% CWE is good for infusion mashing. Anything lower needs a step mash.
You may think that's it ... but no. There's also less common measures to describe degree of modification, like Hartong. I'm sure your head is already spinning, so I'll just give you the cliff notes. A Hartong 45° over 40 is really good and has more than enough enzymes to convert itself and thensome. 39-36 is ok to slightly undermodified. Under 36 is undermodified malt. It's either a sign the maltster is really bad at their job, the malt is designed for decoctions, or it's intended to be used as chit malt.
Another common specification that's the source of confusion among homebrewers seems to be protein content. That's understandable since maltsters will use the words protein and nitrogen interchangeably. This is because protein is the primary source of nitrogen in malt. To switch between nitrogen and protein, you multiply nitrogen by 6.25 to get equivalent protein.
The first thing you'll want to look at is the malt's total protein. This will be given as a percentage of total weight of the barley corn. American malts will tend to have more protein than European malts, but more than ~12% total protein in either will result in hazy beer. Too low a total protein and you might have head retention problems.
The next thing you'll want to look at is the soluble protein/nitrogen numbers. This figure will also be a percentage, but it's a percentage of total protein, not total mass of the barley corn. When barley is unmalted, the carbohydrates are locked up in a matrix of protein. Part of the maltster's job is to break those carbs out of their protein jail so enzymes can come in and break the carbs down into sugars. Some of the well broken down protein ends up as soluble protein and the insoluble protein is typically the larger bits of protein matrix left over. So the higher the soluble protein, the higher the degree of modification of the malt. This can be good, up to a point. You want to be between 35-45% soluble nitrogen to be in an appropriate zone for good beer. Below this range, you could have lautering problems and protein haze issues. Higher than this range and you'll tend to have thin, watery beer.
Occasionally, you'll see FAN listed. FAN stands for free amino nitrogen and it's soluble protein that's been broken all the way down to amino acids or peptides small enough for yeast to utilize. You'll need at least 160-240 ppm of FAN depending on the yeast strain, wort gravity, and pitching rate to ensure a healthy fermentation. Most modern malts fall within this range.
Most homebrewers are familiar with the concept of Diastatic Power (DP), which is the measure of enzymatic content the malt has for converting starch into sugar. DP is given in degrees Linter (°L) in North America and degrees Windisch-Kolbach (°WK) in Europe. To convert between the two:
This figure is somewhat is the intersection of the Total Protein/Nitrogen specification as enzymes are proteins and Extract specifications since those numbers depend on DP. The tricky part of this measurement is that DP is the total enzymatic power; it doesn't differentiate between beta amylase and alpha amylase. If DP is the only measurement you're given, you'll have to do some educated guessing as to where the division lies. It's generally easier to use DBCG/DGFG or HWE/CWE to estimate your mash regime. Just use DP as a guide to know your total potential for conversion. Generally, anything over 35 °L will convert itself. Anything under that will require additional DP to fully convert. Fortunately, most modern North American base malts are in the 120-160 °L (39 - 50 °WK) range and good European base malt will be in the 28-33 °WK (80-100 °L) range.
If you're lucky, your maltster will list Dextrinizing Units (DU), which is the alpha amylase potential broken out from the DP. Use this figure, if given, to help dial in your mash temperature(s) to get the desired wort composition and mouthfeel.
The last major specification to discuss is Mealiness. Mealiness is a measure of the actual physical quality of the grain and how it will respond to milling. The more mealy a barley corn is, the more it has been modified and the protein matrix has been broken down, and subsequently the more it has a tendency to be crumbly and powdery. That is mealiness. The opposite of mealy is glassy. Glassy is exactly as it implies; hard and breaks in a sharp way when milled. This is the opposite of what you want to see in a base malt.
For single infusion mashes, you want at least 95% mealiness in a base malt. Measurements in the 90-95% indicate you need to decoct or step mash, and less than 90% are unsuitable for use as a base malt. Occasionally, you'll see mention of half mealy in the specifications. If mealiness has been broken down into mealy/half mealy/glassy, you want to see your specifications around, you want to see the same mealiness as indicated above, but you want to see more half-mealy than glassy.
Occasionally, you'll see the term Friability given as a percentage. It's almost the same thing as mealiness. Instead of a physical description of the malt, it gives the percentage of malt that falls through a certain sized screen after being milled according to a certain specification. You want the friability to be over 80%.
And there you have it! You have all the basic information you need read a malt analysis sheet. If you haven't been reading the analysis of the malts you commonly use, hopefully now you'll start. If your favorite maltster isn't providing all the information outlined here (or anything else you want to know), be sure to pester them and tell them you'd like it to be available. Knowledge is power!
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