Sizing Starts With the Must, Not the Shell

Most 30,000 L red fermenters we build are ordered around the must load, not the nominal volume. Skin contact and a rising cap add 15–20%, so a tank rated at 30,000 L comfortably handles a 25,000–27,000 L must fill with working room for pumpover. Before drawings are frozen, confirm crush pad height, ceiling clearance for the manway and lid, and floor loading. A full tank at 1.08 specific gravity puts roughly 32 tonnes on four legs.

Cooling Jacket Area

Red fermentation releases the most heat in the first 72 hours. We size jacket surface from your target drop — cold soak at 8–10 °C, fermentation held at 26–28 °C — and from glycol supply temperature, typically -5 °C. A dimple jacket on the lower shell and cone covers most lots; high-Brix fruit usually benefits from a second, smaller jacket on the upper shell for cap cooling. Jackets are laser welded for an even contact pattern and pressure tested at 6 bar before insulation goes on.

Material and Fabrication Choices

304 stainless handles wine and standard cleaning chemistry. We move to 316L when plant water runs above roughly 100 ppm chloride or when chlorinated foam cleaners are in use — weld-adjacent stress corrosion cracking is the failure we see most. Shell and bottom are 3 mm, top 2 mm on a tank this size. Interior welds are ground flush, pickled and passivated, with a wetted finish of 0.4–0.6 µm Ra. Gaskets are food-grade EPDM or silicone and can be changed without cutting anything.

Fittings, Relief and Cleaning

A typical build carries a top manway, a 500 mm hinged lid for punch-down, rotary spray ball, racking arm, sample valve, 2 in. tri-clamp drain and DN50 glycol ports. Pressure and vacuum relief are set so the tank vents CO2 during active fermentation and survives a cold-water rinse without collapsing. CIP runs at 1.5–2 bar supply; we verify spray coverage with water before shipment.

Common Questions

Cone or sloped bottom? For red must we usually build a shallow 15–20° cone or a dished bottom on a 3% slope with a racking arm. A 60° cone earns its cost when you need clean lees separation, not for skin-fermented lots.

Can one tank do red and white? Yes, if the jacket area is sized for the colder white fermentation and the fittings allow a closed top with a fermentation lock.

What do you need for a quote? Batch volume, fruit type, target temperatures, glycol supply temperature, available ceiling height and door width, and your sanitation chemicals.

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