To create malt extract from barley, the process begins with the milling of the grains. The grains are carefully milled to break them down into smaller particles, which allows for better extraction of the desired sugars during the brewing process. This step is crucial as it helps to expose the starches inside the grains, making them more accessible for enzymatic conversion.
Once the grains are milled, water is heated to a specific temperature, usually around 150°F (65°C), in a large vessel known as a mash tun. The heated water, also known as strike water, is added to the mash tun and the milled grains are then added gradually while stirring. This combination of water and milled grains is known as the mash.
During the mashing process, enzymes naturally present in the barley grains, specifically alpha-amylase and beta-amylase, break down the starches into fermentable sugars. The temperature of the mash is carefully controlled to ensure optimal enzyme activity, as different enzymes work best at different temperatures. This enzymatic conversion process typically takes around 60 to 90 minutes.
After the enzymatic conversion is complete, the resulting mixture is known as wort. The wort is a sweet liquid that contains the sugars extracted from the grains. To separate the spent grains from the wort, the mixture is transferred to a vessel called a lauter tun. The lauter tun has a false bottom or filter bed that allows the liquid to flow through while retaining the spent grains.
The wort is then carefully filtered through the lauter tun, separating the liquid from the spent grains. This filtration process helps remove any solid particles and husks, leaving behind a clear liquid. The extracted wort is then transferred to a separate vessel for further processing.
To produce malt extract, the wort is concentrated by evaporating a significant portion of the water content. This is typically done using a vacuum evaporation process, which allows for lower temperatures and helps preserve the delicate flavors and aromas of the malt.
During the evaporation process, approximately 80% of the water is removed from the wort, resulting in a thick, sticky substance known as liquid malt extract (LME). LME is highly concentrated and rich in fermentable sugars, making it an excellent ingredient for brewing beer or other fermented beverages.
The final LME product can be packaged and stored for later use. It provides brewers with a convenient and consistent source of fermentable sugars, allowing for more control over the brewing process and the ability to replicate specific beer recipes.
The process of making malt extract from barley involves milling the grains, mashing them with hot water to extract the sugars, filtering the resulting wort to remove spent grains, and evaporating a significant portion of the water to create a concentrated liquid malt extract. This extract is then used as a key ingredient in the brewing of beer and other fermented beverages.