≈8–12 kg per hectolitre from energy (plus fermentation CO2, which is biogenic and often recovered). A 1 Mhl brewery ≈ 1,000 t fossil CO2/yr — all abatable with current technology.
From our guide: Decarbonizing Brewing — full context, charts and sources there.
Boilers, kilns, heat exchangers, valves and steam lines lose energy continuously. Inzonex makes patented (UK GB2508992.1) removable modular insulation — snap-fastened covers engineered per temperature tier, not generic off-the-shelf jackets: