Understanding Beer Science: From Barley to Fermentable Sugar

From Barley to Malt: The First Step in Brewing

Everything starts with barley, a raw grain that needs to go through a carefully controlled process called malting to become the malt — the foundation of beer. During this stage, the grain “wakes up,” activating internal mechanisms essential for producing the sugars that yeast will later consume during fermentation.

Malting Process Steps

1. Steeping: Grains are soaked in water for 24–48 hours, increasing moisture from 12% to around 45%, which activates the grain’s metabolism and starts germination.
2. Germination: Over 3 to 6 days, enzymes like amylases, proteases, and glucanases are produced. The internal structure of the grain starts breaking down, making starch more accessible.
3. Kilning (Drying & Roasting): Germination is halted by drying the grain. Moisture is reduced to about 10%, while flavors, aromas, and color develop. This step also determines enzyme preservation based on temperature.

How Malt Becomes Sugar — Enzyme Action During Mashing

Before mashing, the dried malt is crushed to expose its internal content, especially the starch. During the mashing step, the crushed malt is mixed with hot water, activating the enzymes produced during malting to convert starch into simpler sugars.

• Alpha-Amylase: Works best at 72°C to 75°C (162°F to 167°F), breaking starch into dextrins, which contribute body and residual sweetness.
• Beta-Amylase: Works between 60°C and 65°C (140°F to 149°F), producing maltose, the preferred fermentable sugar for yeast.
• Proteases: Break down proteins, improving foam stability and clarity.
• Glucanases: Break down beta-glucans, aiding in wort filtration.

Temperature: The Brewer’s Best Friend

The chosen mashing temperature affects the balance between fermentable and non-fermentable sugars, influencing the beer’s body, sweetness, and dryness.

From Wort to Fermentation

The resulting wort is rich in fermentable sugars, ready to be transformed by yeast into alcohol, CO₂, and a variety of flavorful compounds that define the beer’s character.

Brewer’s Fun Fact