What do malting and mashing mean to you? Malting refers to the processing of raw grains, while mashing has a broader definition. Let’s explore why these terms can be flexible and how brewers can benefit from understanding them.
The malting process begins with raw cereal grain seeds, often barley but sometimes wheat, rye, or oats. The seeds are steeped in water to hydrate them. Then, like a gardener starting seeds for a garden, the maltster germinates the seeds in a warm and humid environment. This germination step is crucial for brewers because it activates key biological processes, including the formation of enzymes needed during the mashing process. Without germination, starch conversion cannot occur, which means no sugar, no fermentation, and no alcohol.
All malted grains go through germination, but after that, the processes diverge, resulting in various malted grains. The duration of sprouting affects the proteins, enzymes, and starches. The malt can then be toasted/kilned, drum-roasted, or stewed. Toasting can range from light toasting to stop enzyme activity and create base malts, to further toasting that destroys enzymes and produces specialty malts like biscuit malt. Roasted malts are made by heavy toasting in rotating drums, and different roasting profiles yield specialty malts such as pale chocolate, chocolate, and black.
Alternatively, grains can be stewed, resulting in caramel/crystal malts. Stewing treats the grains similarly to mashed grains, but without crushing. Starch in the grains is converted to sugar inside the grain. After stewing, the grain is toasted to varying degrees, depending on the desired crystal level. The fact that these malts contain sugar instead of starch is significant, as they have a different taste compared to toasted grains. The conversion of starches to sugars also allows these grains to be steeped for flavor and a mix of fermentable and unfermentable carbohydrates.
By the time brewers purchase their grains, all these processes have been completed. The maltster has set the stage, and now it’s the brewer’s turn to prepare for the yeast. The sugar profile of the wort, which is the sugar water produced by the brewer, depends on grain selection, mash temperature profile, and duration. Enzymes created during germination break down the complex starch molecules. The mash temperature determines which enzymes are favored, each working on starch granules differently. Cooler and longer mashes create drier beer, while warmer and shorter mashes result in fuller-bodied, sweeter beer with more unfermentable carbohydrates known as dextrins. Adding more specialty grains to the mash increases the presence of unfermentable sugars in the wort.
Now, what about malt extract? The maltster completes the process as they would for standard malt. However, they employ a brewing team to make the brewer’s wort in a large mash. After the mash phase, the wort is vacuum boiled to concentrate the solution while minimizing chemical reactions that typically occur in a boil kettle. Once the wort is reduced to about 80% sugar content, it becomes liquid malt extract. This liquid can be further concentrated through spray drying, resulting in dried malt extract with no water. Malt extracts essentially provide brewer’s wort in a concentrated form. The downside is that brewers lose control over mash parameters mentioned earlier. Skilled extract brewers can still adjust these parameters using techniques like sugar substitutions or using steeping grains to create a fuller-bodied beer.