Brewing Terms
Brewing Terms · process and fermentation vocabulary
Brewing has a dense technical vocabulary. These definitions cover the process and fermentation terms used in the brewing sections of this site, with GF-specific context where relevant.
| Term | Definition |
|---|---|
| Attenuation | The degree to which yeast has fermented available sugars. Expressed as apparent attenuation (%) = (OG − FG) / (OG − 1) × 100. GF worts can produce different attenuation profiles than barley worts. |
| Beta-glucan | A soluble fiber found in grain cell walls. High beta-glucan content causes viscous wort and slow lautering. GF grains vary in beta-glucan content; millet tends to be higher than sorghum. |
| Cold side | The post-boil stages of brewing: whirlpool, chilling, fermentation, conditioning, and packaging. Gluten cross-contact risk decreases significantly on the cold side if hot-side controls are in place. |
| Dry hopping | Adding hops directly to fermenting or conditioning beer without boiling. Contributes aroma without bitterness. No GF-specific risk, but hop certificates of analysis should confirm no gluten-containing adjuncts. |
| Flocculation | The tendency of yeast cells to clump together and settle out of suspension at the end of fermentation. High-flocculation yeast clears faster; low-flocculation strains stay in suspension longer. |
| Hot side | The stages of brewing from milling through the end of the boil. Cross-contact risk is highest here if GF and non-GF production share equipment. |
| IBU | International Bitterness Unit. A measure of the isomerized alpha acid content of beer. Perceived bitterness depends on IBU relative to malt sweetness (balance). |
| Original gravity (OG) | The specific gravity of wort before fermentation. Indicates fermentable sugar content and predicts potential alcohol content. |
| Trub | Protein and hop material that settles out of wort during and after the boil. Managing trub carryover into the fermenter is important for GF beer clarity and flavor stability. |
| Vorlauf | Recirculating the first wort runnings back through the grain bed at the start of lautering to clarify the wort before running off. Particularly important in GF brewing where the grain bed is less stable. |
Source Notes
Brewing term definitions based on MBAA Practical Handbook for the Specialty Brewer, Kunze Technology Brewing and Malting, and GF brewing process literature.