Maltsters produce numerous measurements of their malt for quality control reasons. When you purchase a huge amount, you receive measurements for that specific batch. Those who buy in lesser quantities have to settle for more general descriptions, for most homebrewers this is enough. Most maltster post their specs on the Internet, making it easy to find information on what you’re using.
Moisture Content (MC)
This stat is usually provided as a percentage. Generally lower is better, stay away from malts with moisture content of 5% or more, as they have been incorrectly stored.
Usually provided in degrees Lovibond. European malts apply the European Brewing Convention (EBC) units. EBC = Lovibond × 2.
Extract, Dry Basis, Fine Grind (DBFG) & Extract, Dry Basis, Coarse Grind (DBCG)
Brewers refer to sugars as “extract” and so a lot of malt analysis contains an entire group of values for conveying extract. The important two are Extract Yield Dry Basis Fine Grind (DBFG) and Extract Yield Dry Basis Coarse Grind (DBCG). These are calculated from a laboratory mash performed using a tiny quantity of the malt. The technique used is different from actual brewing conditions; however the fine-grind results signify the maximum possible laboratory yield from the malt. When using base malts, a DBFG value less than 78 percent signifies poor quality. Due to the way they are produced, specialty malts usually have lower yields, this is not an issue as they are generally not significant providers of extract to beer.
The coarse-grind numbers are used to show the brewer the maximum that can be attained using a crush which approximates that used by the majority of breweries. This value is still larger, than most homebrewers attain as the mash is “oversparged” compared to normal brewery processes. In reality, mashing environments at a brewery usually result in a yield 5–15% lower than the DBCG value. Keep in mind that both of these numbers are reported on a “dry basis,”, as if the moisture percentage of the malt was zero. This is done to make comparisons between different malts easier.
Brewers sometimes discuss malt’s “extract potential.” This is usually given as specific gravity that can be achieved with 1.00 pound (455 g) of malt mashed in 1.00 gallon (3.78 L) of water.
This formula is used to determine extract potential:
Extract potential (S.G.) = 1 + (DBFG / 100) * 0.04621
The variance between the fine grind and coarse grind extract shows the amount of malt modification. Use malts with an FG-CG difference of less than 2.0%, except if you are using decoction mash.
Diastatic Power (DP)
This quantifies the amount of alpha and beta amylase in the malt, which is basically the starch-converting power of the malt. Six-row lager malts have the strongest diastatic power, followed by two-row Pilsner, lager, and pale ale malts. Darker kilned malts have low diastatic power and malts above 25°L usually have no diastatic power.
This is given as a percentage. It is advised that all-malt beers should not be brewed from malts which surpass 12% protein. S/T (SOLUBLE NITROGEN/TOTAL NITROGEN RATIO) is an indicator of the amount of modification. Higher is preferred for most home brewers. Malts below 30% are under modified and may require decoction.
This is a measure of texture, and is an additional indicator of modification. The mealier a malt, the easier it will mash. Glassy grains do not crush well. Try to find malts with at least 92% mealy grains for step mashes or decoctions, and no less than 95% mealy grains if using single-step infusion mashes.
Malt size is determined by passing it through standardised sieves. Fatter malts are preferred; however uniformity of size is also an important element to look for. Thin or thru refers to malt that is below 2.2 mm. Try to find malt that is 2% or less thin or thru.
This is a measure of how thick the wort will be, and is an indicator of glucans or other long carbohydrates which lead to slower movement. Higher than 1.75 is considered to be high.
This denotes any positive or negative odours noticed in the mash. The majority of specialty malts will be very aromatic.
Most malt is clear to slightly hazy. Well kilned specialty malts will be noted as dark.