Article

Master Malt Analysis

Barley is an agricultural product, and therefore changes year to year. As brewers, we typically don’t use barley raw from the field — it won’t provide us the enzymes we need, nor is it as easy to store. We require another step in the process; malting. This is another variable added to the always changing malt we use. Typical analysis specifications and certificates of analysis that are provided by the maltster help us make sense of these changes. We can be better homebrewers if we understand what those factors and changes are so we can either physically adjust for these variables, or at least emotionally understand that beer ingredients are ever changing. If you’d like to be able to reproduce your beer it’s even more critical you understand these barley-to-malt, batch-to-batch, and brew-to-brew changes.

You may already be adjusting your hops based on the given alpha acid units, why not your malt? The first reason may be information access as a homebrewer. You may need to get in touch with the malting company directly and provide them a lot number for your malt if you want to see a certificate of analysis on your particular lot. You may not care if your gravity is different by a couple points each time. Or your color is off a couple degrees batch-to-batch. Still, understanding why this happens is valuable. Some adjustments may be so slight — a few ounces of malt here or there, you may not choose to make them. We can be better homebrewers, worry less, and enjoy our beer more if we see the numbers provided and have a general understanding of what they mean.

Lot Analysis vs. Typical Analysis

Most maltsters will be willing to provide a lot analysis sheet, often called the certificate of analysis, or COA. This analysis defines malt in terms of color, moisture, extract, protein, size, and possibly an assortment of other information. If the malt was kilned or floor malted, and intended for use as a base malt, the analysis will also provide further detail like diastatic power (DP), an indicator of the malt’s capacity to turn starch into sugar.

A typical analysis lists ranges or an average for a particular malt. Many maltsters keep their typical analysis numbers online. Although useful, ranges may not be listed, and can be quite dramatic, especially on darker malts. If an average number is given, you may not know what sort of range a malt has. Often a caramel 20 °L malt can finish in a roaster or kiln between 15 and 25 lovibond and still fall within the maltster’s color specification.

General Malt Descriptions

It’s good to understand that we segregate malt by style, which often is an indicator of process. For the purpose of reading a typical analysis or COA, it’s helpful to understand that there are two major categories of malt — base malt and specialty malt. Oftentimes specialty malt has less analysis provided as we aren’t relying on it for starch or enzymes during the mash — critical numbers to know with
base malt.

Base Malts:

These malts provide most of the wort’s starch and enzymes that produce the extract. Base malts include: Pale (American two-row), pale ale, Pilsner (or Pilsen), Vienna, and Munich. All can be quite different but serve as the base of a beer, as they provide the appropriate enzymes to convert starch to sugar. Base malt will make up from 80–100% of the malt bill for most beer styles. The analysis of these malts is often a bit more specific and in-depth because of this. Malting specifications may be a bit more stringent as well to help the brewers receive a consistent product — it matters much more when it’s the majority of your beer.

Specialty Malts:

Color or specialty malts are made in a kiln and/or a roaster and include: dark Munich style, caramel/crystal, dry roasted malts, and specialty roasted malts. These malts will contribute significantly to color, flavor, mouthfeel, foam, and aroma. These malts can be a critical player in all of the forementioned attributes.

It’s also good to remember that there are always changes in barley variety, growing region, and seasonal weather that can have big effects on how malt tastes and its attributes. Although these considerations are taken into account by the farmer and maltster as they choose barley, these are further variables passed through to brewers looking to make a
consistent beer.

Measuring Malt

Maltsters in the United States use guidelines for testing and analysis from the American Society of Brewing Chemists (ASBC). In Europe, the guidelines are similar (if not the same), and are written by the European Brewing Convention (EBC). These organizations guarantee that everyone is using the same tests, and thus, providing similar values across their lab work.

There are a multitude of maltsters out there these days. Many are smaller, local companies. As the process gets more hands-on, it’s often trickier to put processes in place that create consistent batches. It’s best to get your hands on a certificate of analysis when using craft malt on a regular basis, as you may need to make adjustments from batch to batch if you’d like to see some consistency in your own brewhouse. Let’s take a look at what analysis is performed in the maltster’s lab. You may find some analysis has more or less of the data listed below. I’ve provided the variables I believe are most valuable
to you.

Extract, Dry Basis Fine Grind (DBFG)

This value is provided as a percentage and is used to determine the maximum extract yield a malt can offer. The malt is milled to a near flour consistency, and a “congress mash” is performed. This is typically only 50 grams of malt. The higher the DBFG number the better. It means there’s more soluble starch, and less husk and protein in the makeup of the malt. Most maltsters these days strive for at least 80% extract, with a typical range for many base malts between 77–84%. Many brewers like to see this number be as high as possible as they see it as a measure of both quality and value — the higher the extract, the more bang for their buck from their base malt. If you see numbers below 76% on a COA, you may want to question the barley being used or the malt/malting process.

Extract, Dry Basis Coarse Grind (DBCG)

If you’ve guessed that DBCG is the same test as above with a much coarser grind, you’d be correct! This simulates a more “real world” mashing scenario, and often comes in just slightly lower in extract than the DBFG test, which really should give us our upper limit of extract potential. A more useful and often performed malt test, “Extract, Coarse Grind As-Is” can give us an even closer look at how a malt may perform when we brew with it. This malt reflects the closest mash performed in a lab that mimics a brewhouse. Both of these tests have values that typically fall between 76-83%. An “extract, coarse grind as-is” may still prove to be about 10% above the efficiency you’ll see in your brewhouse, just due to the testing environment and efficiencies of lab equipment and the testing process.

Difference, Fine Grind vs. Coarse Grind (FG/CG)

The difference between the above two numbers can be valuable information as well. If you’re using a malt that’s 82% DBFG and 81% DBCG, you have a difference of 1%. “This difference is really an indicator of modification,” states Dan Bies, Technical Services Manager at Briess Malt, “anything less than 1.5% indicates a well-modified malt, with the potential for higher extract yields when using just an infusion mash.”

Color, Lovibond (L)/Standard Research Method (SRM)

It might go without saying, in most cases 100% of beer color is derived from malt. Sure, you might make an oak-aged chocolate cherry blonde ale from time to time, and those additives will color your beer. When it comes down to it, malt can easily help you dial in the perfect color one day, and throw your perfected Pilsner out of whack the next.

You probably use color quite often to choose a malt. Although malting companies still express color in degrees Lovibond (°L), they probably haven’t used the test since the 1950s. Instead, the Standard Research Method (SRM) was developed using a spectrophotometer, giving a much more accurate process with which to test. The two ratings are nearly equivalent, and old habits of using °L to express °SRM color on typical analysis and COAs is near industry wide. In Europe you may find malt measured in only EBC, which can be determined by taking °SRM (or °L) and multiplying by 1.97.

In effect, color can be one of the largest determinants you use when choosing a malt. If a recipe or style calls for Munich malt, understanding the wide range of offerings often comes down to what degree of color it is, from 5 °L to 30 °L. Even a base malt like Pilsen can range from 1.2 °L up to 2.9 °L. The darker Pilsen malt more than doubles the lightest color on offer and more than doubles the color of the beer made from it.

Alpha Amylase, Dextrinizing Units (DU)

This is simply a measure of the alpha amylase present, and is shown in dextrinizing units (DU.) This is a great indicator of whether or not your mash will convert properly given time. A range of 30–50 is typical for a base malt. Lower numbers may mean a more complex mash, or a longer mash time is necessary. Most base malt is well-modified during the malting process, allowing for good alpha amylase numbers. It would not be released (or possibly even malted) if it wasn’t able to perform the task of chopping up starch into short chain dextrin, allowing beta amylase to easily convert dextrin into fermentable sugar, a critical performance check.

Diastatic Power (DP)

This is an indication of the total enzyme power of a malt, both alpha amylase and beta amylase. Most base malt has a range shown in degrees Lintner of 50 °L to 150 °L (not to be confused with degrees lovibond). Often if your mash average is below 40 °L you’ll find your conversion will take much longer, if it converts fully at all. Lintner for a batch = (lintner total of grain X weight of grain) / (total
batch weight).

Assortment, Plump

You may find neither of these words on a typical analysis, but the numbers should be available. What assortment refers to is kernel size, and the values you will see are expressed as a percentage of kernels that do not sieve through screens with gaps of  7⁄64 and 6⁄64 inches.

The test consists of four trays stacked from top to bottom with diminishing screen sizes — the top with a 7⁄64-inch screen bottom, the next with a 6⁄64-inch screen, the third with a 5⁄64-inch screen, the final tray at the bottom is solid. The trays are placed on a shaker with a 100-gram sample. After three minutes each tray is weighed.

What we want to see as brewers is that most of the kernels are plump, or not falling through the first two top trays. 80% plump, would mean that 80 percent of the kernels were in the 7⁄64-inch and 6⁄64-inch screen. We typically want base malt that’s at least 80% plump or it could affect brewhouse efficiency, as it is more difficult to evenly mill various sizes with a two-roller mill. Adding a third roller with some finer adjustment may help. Specialty malt, due to the process or type of barley used may not be as plump. You may consider milling this malt separately if you have a two-roller mill with an
adjustable gap.

If more than 3% of grain is making it to the final tray (also called “thru” or “thin” malt,) you may want to have a talk with your maltster — this can lead to extract issues due to milling and due to the quality of the malt. Seeing a high thru number may also translate to lower than expected extract numbers (FGDB) on your analysis as well.

Friability

Friability is a test of malt modification. The malt is crushed using a friability tester. When crushed, the ideal result of most base malt is that it easily crumbles, showing that the starch will be easily soluble in a mash. In general, specialty malts like roasted barley are highly friable, and are not tested. When measured as a percentage we want to see results at or above 85%. As brewers, we can easily single-step infusion mash any malt with this kind of friability. If you’re using a malt with a friability of less than 85%, say a floor-malted Pilsen that has been left under-modified (hopefully intentionally), you would want to perform a step mash to help convert the malt.

Glassy/Mealy

Finally, a test almost specifically for specialty malt! Although you may find glassy or mealy percentages on your base malts, it’s mostly used to let you know if your caramel malt is filled with sugars that have “crystallized” and turned glassy inside the kernel. Malt is cross-cut with a device called a farinator and examined for a mealy white center, or a “glassy” bead of sugar.

Most caramel or crystal malt should be at least 90% glassy, though some lighter-colored crystals may be “half glassy” or could be only 80% glassy, depending on the process. This test may also be used on special process malts that are roasted. These malts may have their own typical glassy and half-glassy percentages. If you’re not seeing your base malt at close to 100% mealy, then you know something went wrong with the malting process.

Roaster-produced crystal-type caramel malt will have 90% + of the kernels containing only glassy crystal like converted sugar. Kiln produced caramel malt will have a large proportion, usually about 50% of the kernels mealy and starchy on the inside, just like high-dried or Munich malt. Top: Kilned (note about 50% mealy). Bottom: Roasted (note >90% glassy)

Viscosity

Measured in centipoise units (cP), viscosity is a measure of wort flow through tiny capillary tubes. If the wort is able to run quickly through this viscometer it indicates that you’ll have an easy time sparging out. A high wort viscosity would indicate the malting process did not properly break down the endosperm cell walls of the barley kernel. Anything indicated over 1.7 cP may struggle to runoff (lauter) efficiently when sparging. If you think you might have issues, you can decoction or step mash starting with a 15 to 20 minute rest at 104 °F (40 °C) to help dissolve some of these beta-glucans.

These items we have run through so far are some of the most valuable, and useable numbers you’ll find on a typical malt analysis, or a certificate of analysis for a certain lot of malt.

Other Analysis Provided

You can argue that all analysis is valuable, but with the values gone over up to this point you can determine if some other items will be valuable or not. The items I will briefly describe now may be as valuable to brewers as the previous analysis, and will help build a better picture of your malt.

Protein: Expressed as a percentage, most brewers hope to see this below 12%. Anything higher may show up as haze in your beer. It may also lead to lautering issues.

Soluble Protein (SP): Also expressed as a percentage, its primary task is to provide us a ratio of protein in our beer shown as S/T (soluble protein/total protein.) When dividing soluble by total protein, we want a number above 30% or we could run into
lautering issues.

Free Amino Nitrogen (FAN): This measures the amount of free amino nitrogen available. It’s critical for yeast growth during fermentation. Many brewers want to see at least 170 ppm available in their base malt, although others argue that a lower FAN will help with beer stability as FAN influences oxidative stability.

Beta Glucan (b-glucan): High levels are associated with lautering issues. Numbers above 180 ppm in your base malt may be worth a mash step at 115–120 °F (46–49 °C) for 15–20 minutes.

Turbidity: Measured in Nephelometric Turbidity Units (NTU), turbidity above 15 NTU listed may mean you’re in for a bit of haze in your beer. Typically 5 NTU or less will signify a good clarity, and less solids, in your beer.

Demystifying Malt Analysis

Malt analysis doesn’t need to be random numbers that mean little to you. Consistency isn’t always a given, and quality can be measured. As homebrewers strive to make even better beer, unlocking the potential of your malt is a logical step.