Carbonation

Carbonation is the dissolution of CO₂ gas into a liquid under pressure. In beverage processing, it is the defining process for CSDs, beer, and sparkling water. Carbonation is measured in **volumes of CO₂**, 1 vol CO₂ means 1 litre of dissolved CO₂ per 1 litre of liquid (at STP). Typical Indian beverage targets: - Plain soda water: 4.0–5.0 vol - Cola: 3.8–4.2 vol - Lemon CSD: 2.5–3.5 vol - Tonic water: 4.0–4.5 vol - Beer: 2.3–2.7 vol - Sparkling water (lightly): 2.5–3.0 vol Equipment: **in-line carbonator (CO₂ saturator)** is standard. Liquid is chilled to 2–5°C (CO₂ absorbs better in cold liquid), then sprayed across CO₂-saturated chambers under pressure (typically 4-5 bar). To hold the carbonation through filling, **isobaric (counter-pressure) filling** is mandatory.