Why a red wine tank is not just a bigger beer tank

Must is heavy, abrasive and full of skins. A vessel that handles clarified wort without complaint will show its weaknesses quickly once it is loaded with crushed fruit at roughly 1.2 t/m³ and punched down twice a day. Our 500 L to 100 HL red wine fermentation tanks are built around that: thicker shell plate, a reinforced cone-to-shell transition, and a top manway sized for pomace removal rather than simple inspection.

Cooling: spiral channel versus dimple jacket

The spiral cooling channel is welded directly onto the cone and lower shell, where the heat load sits during the first 72 hours of fermentation. Glycol enters at 2–4 °C, and the achievable pull-down depends on jacket surface area, not on pump size. On 100 HL tanks we normally split the channel into two or three independent zones with separate solenoids, so one sluggish zone does not force you to chill the entire volume.

Dimple jackets cost less and work well below 30 HL. Above that, spiral channels deliver better coverage per square meter of plate and stay cleaner when the glycol loop is filtered.

Materials and fabrication

SUS304 is standard for the inner shell. We move to 316L when the juice runs high in chloride or when the tank doubles as a storage vessel with repeated SO2 additions. Interior welds are ground flush, pickled and passivated, then polished to Ra ≤ 0.6 µm if the winery asks for it. Exterior is 304 with a No. 4 finish, or mirror polish in cellars where the tanks are visible. Insulation runs 80–100 mm polyurethane under stainless cladding, which is what actually holds temperature in a cellar kept at 12 °C.

Working pressure is typically 0.2 bar on open-top style vessels, or 1.5 bar on closed tanks fitted with a combined pressure/vacuum relief valve and tested at 2 bar. Cone thickness and valve rating have to be decided together, not after the tank lands in the cellar.

Fittings and cleaning

Standard fit-out covers a 500 mm top manway, racking arm, sample valve, 1.5 in thermowell with RTD, CIP spray ball, and DIN or tri-clamp outlets. Send a cellar layout and we can pre-pipe the glycol header before shipment.

Specifications

FAQ

Can one tank handle both fermentation and storage? Yes, if it is a closed vessel with a pressure rating and relief valve. Open-top tanks are for fermentation only.

How do I size the volume? Divide your batch by 0.75–0.80. The headspace is not spare capacity, it is room for the cap.

Is a racking arm necessary? For separating free-run wine from gross lees, yes. Without it you are pumping cloudy must.

Tell us your batch size, grape variety, number of tanks and available cellar space. We can recommend the tank volume, cooling area and configuration for your winery.