Malt is most often defined by the following elements:
common or historical name (e.g. pilsner, pale ale), although it is not always clear what parameters and flavor a given malt should have;
production method (e.g. floor-malted, smoked, roasted), although in this case too, the parameters may be relative;
place of origin (e.g. English, Belgian malts), which refers to tradition but does not necessarily have any significance for the product itself;
malt or barley variety (e.g. Maris Otter, two-row), which usually is not particularly significant to the brewer;
trade name or manufacturer’s proprietary name (e.g. cookie, melanoidin);
other characteristics: flavor, internal grain structure, coloring properties, base grain, etc.
Each malt can be described quite precisely using physicochemical parameters provided in specifications. To some extent, these parameters reflect the properties of the malt. However, brewers argue both in the literature and in private conversations about which parameters are important and what values for them are desirable.
Since it is not possible to categorize all malts available on the market or compare them in any other way than by comparing the specifications published by manufacturers, the most important categories of malt from the perspective of production methods and names are included below.
The current maltster offering is the result of several factors: tradition, brewing and malting knowledge, the needs of breweries and their vision of the ideal malt, and, more recently and increasingly, the development of craft beer. Homebrewers and brewers working in small breweries often have specific expectations, but they are now such a strong group that they are able to create demand for malt produced specifically for their needs. Therefore, the following groups of malts currently popular can be distinguished:
Light malts dried on screens, forming the base of the grist
These malts are often characterized by very high enzymatic activity. Since the 19th century, pilsner malt has usually formed a fairly flavor-neutral base for most lagers and other beers in continental Europe. It is used interchangeably with pale malt (also called pale ale malt, because it was used for British beers or top-fermented beers), which is also very light in its Central European version. Pale ale malt produces a slightly darker color and minimally more biscuit and malty aromas. Most consumers probably would not be able to distinguish between these malts. Due to the preferences of breweries, some maltsters in Belgium and the United Kingdom produce somewhat darker pale ale malts.
In the United States, the basic light malt, the equivalent of pilsner malt (sometimes minimally darker), is pale ale malt, usually called two-row, referring to the fact that two-row malts are generally produced in Europe. It is essentially no different from European pilsner malt. In America, we may encounter light six-row malts, which are cheaper and contain more enzymes and protein, and are used mainly by large breweries.
Another light malt used as a beer base is Vienna malt, usually used as a base for Vienna lagers. It is generally described as somewhat darker than pale ale malt, but after analyzing specifications, it turns out that for some maltsters the opposite is true. It is worth adding that light malts are produced from different varieties of malting barley, which are sometimes mixed together.
What should you pay attention to when choosing a base malt? Opinions on this issue are divided. Generally speaking, base malt should have the following characteristics:
Low level of β-glucans. A high level of β-glucans can make lautering more difficult and indicates a low degree of malt modification.
Appropriate extract content (extract yield). In good-quality malts, it ranges from 80 to 84 percent. In larger breweries, this may be an important economic consideration. However, the brewhouse process itself has a much greater impact on brewhouse efficiency. According to some brewers, extract yield should not be excessively high, because excessive modification negatively affects flavor.
Appropriate enzyme activity. Important from the perspective of large breweries and distilleries, which use enormous quantities of unmalted raw materials, but completely insignificant for craft brewers.
Appropriate malt modification (friability). High friability makes it easier for enzymes to reach the starch.
Appropriate Kolbach index. This value determines the degree of protein modification. Joe Hertrich, a popular American maltster, suggests that this is one of the most important characteristics of malt, and that low protein modification means the malt has not been modified sufficiently. In the literature, however, opinions differ on how to interpret the results. Large breweries do not use this parameter at all.
Barley variety and country of origin. These elements are only indirectly related to the parameters and flavor of the malt.
Specific color. Color depends on the barley variety and the malting process. It is often, though not always, associated with the presence of additional aromas.
Malts based on roasted light malt, used as an addition to the grist
Light roasted malt is often called biscuit or cookie malt because of the aromas it imparts. It has a floury structure. It does not add sweetness to beer, but rather specific roasted notes that greatly enhance the aroma of certain styles. In the case of dark roasted malt, there is a whole range of malts called coloring or chocolate malts, which add roasted, burnt and coffee aromas to beer; in lighter versions they are reminiscent of chocolate, while darker versions resemble ash. Brewers mainly pay attention to the color and flavor added to the beer, considering the remaining parameters less important.
Malts made from moist green malt or soaked pilsner malt
They are often referred to by the same names: caramel, cara or crystal, which creates some confusion. Due to the specific crystalline structure of the grain, English malts have come to be called crystal malts, although the process by which they are made is analogous. Sometimes all malts produced in this way are incorrectly called caramel malts (for maltose to caramelize, a temperature of approximately 180 degrees Celsius is necessary; under other conditions, caramel simply will not form in the grain or there will be very little of it). Brewers most often pay attention to the color and aromas these malts impart to beer, while considering the other parameters less important.
Specialty malts made on screens
This group includes darker base malts in which, due to specific germination and drying conditions, non-enzymatic browning reactions or partial conversion or gelatinization of starch occur. Malts dried at a higher temperature are usually characterized by a more complex bready and honey-like aroma resulting from Maillard reactions. Malts containing larger quantities of sugars formed in the moist grain during production and subsequently heated are called stewed malts. In addition to their distinctive flavor, they also contribute dextrins to beer, increasing its fullness and head stability. They also slightly lower the pH value, which is worth taking into account during mashing.
This is only a basic classification of the most popular malts according to their characteristics and production methods. Many maltsters strive to create a product that is as closely tailored to the customer’s needs as possible, or even to anticipate those needs. The key to success in the changing beer market is introducing new malts and testing them together with brewers.