Ever curious about how your barley gets converted to malt? This video by the Malt Academy at the Canadian Malting Barley Technical Centre gives you a step-by-step look at the malting process.
Once barley grains have been cleaned and sized, they are converted into malt through three carefully controlled stages – steeping, germination and kilning. Here’s a summary from the video:
Stage 1: Steeping
The steeping process initiates malting by providing water and oxygen to the resting embryo. Steeping also causes hydration of the starchy endosperm, facilitating its partial breakdown by hydrolytic enzymes during germination. Additionally, the barley is washed, cleaning away materials that may hinder the malting process or reduce the final malt quality.
The steeping stage usually consists of several alternately arranged “wet periods” and “dry periods,” which takes up to 48 hours. As the barley absorbs water, it begins to respire, taking up O2, releasing CO2 and generating heat.
Barley moisture levels are increased to 42 to 46% for production of pale-type malt. After the barley obtains the target moisture levels and is chitting equally, it is moved to the next stage.
Stage 2: Germination
In this stage, the barley is transferred into a germination vessel. Germination usually takes up to four to five days, depending on the variety being processed and the expected malt specifications.
Cooled and humidified air is supplied to barley to provide O2, to maintain the barley moisture content, and to carry away CO2 and heat. Temperature control is generally maintained in the range of 14 to 20°C, depending on progress of modification and the type of malt being made. During germination, maltsters are concerned with barley’s respiration activity, vegetative growth, production of hydrolytic enzymes, and their action on the endosperm.
Green malt is then moved from the germination vessel to the kilning stage.
Stage 3: Kilning
The kilning vessel performs the third and final step of the malting process, which involves a free drying/withering phase and a curing phase.
Warm and dry air flows through the germinated grain in the kiln taking off the excessive moisture and developing desired colours, flavours and aroma in the final product.
After kilning, which takes between 24 to 36 hours, the malt is cooled to room temperature to avoid further colour formation and enzyme destruction. Malt is then cleaned to remove rootlets, sprouts and loose husks. The finished clean malt, with about 4% moisture, can then be stored.
All maltsters strive for uniformity in the processes of steeping, germination and kilning; this ensures that the malt meets the functional requirements of brewing, distilling or food processing.
Check out more videos by the Malt Academy here: http://cmbtc.com/malt-academy/. The unique training institute located in Winnipeg offers a variety of programming related to the malting barley and malt industries.