What a 7BBL Unitank Actually Does on Your Floor

Most breweries that contact us about a 7BBL fermenter are already producing — they have a brewhouse running, they have demand, and their existing tanks are either full or too small to make the turnaround work. A 7BBL vessel sits in a practical middle zone: large enough to keep a small taproom supplied or feed a growing distribution account, small enough to fit through a standard roll-up door and run on a modest chiller.

We build these as unitanks by default, which means fermentation and conditioning happen in the same vessel. That saves floor space and one transfer, but it also puts more demand on temperature control. That\’s why the cooling jacket geometry matters more than most buyers expect.

Jacket Design and Why It Determines Your Fermentation Schedule

A single jacket wrapped around the cone is not enough for a 7BBL batch when you\’re crashing from 68°F to 38°F on a Friday to keg on Monday. We typically fit two or three independent zones — cone, lower cylinder, upper cylinder — each with its own solenoid and thermowell. During active fermentation, the cone zone does most of the work because that\’s where yeast generates heat. Pulling a hard crash on the cone only will stratify the tank and stall the batch.

Dimple or pillow-plate jackets on the cylinder give more surface contact for the same coolant volume. We weld them at 100% penetration on the shell side and pressure test every zone at 1.5x working pressure before it leaves the shop.

Material, Welds, and Finish

304 is the standard for beer because it handles wort, caustic CIP, and peracetic acid without the cost premium of 316L. We move to 316L when a client is running high-chloride water, sour programs, or storing finished product long-term. Both grades get fully pickled and passivated internal welds — the heat-affected zone is where corrosion starts if it\’s left alone.

Internal finish is typically 2B mill on the shell with ground welds to a Ra of 0.8 µm or better in the cone and around ports. All internal surfaces can be polished mirror if your QA process requires it. The manway gets a food-grade EPDM or silicone gasket, and we offer a shadowless manway on request for cleaning verification.

Every tank is hydro-tested, then checked with a boroscope at the welds. Connections are Tri-Clamp throughout — racking arm, sample valve, CIP spray ball on a separate port, blow-off arm, and PRV.

Pressure, Safety, and the Details That Cause Failures

These tanks are rated for 15 psi working pressure, with a 30 psi test. The PRV is not optional, and it must be sized to the tank — not to whatever fits the port. A blocked or undersized relief valve on a tank where fermentation is still active is how you rupture a manway gasket at 3 AM.

Carbonation in a unitank means you need a pressure-rated vessel and a carbonation stone port near the bottom. We add that port as standard on any tank spec\’d for brite service.

Specifications

Applications and Sizing Reality

7BBL works well for breweries running 3–5 brews a week and packaging into kegs. If you\’re planning to move into cans with a canning line, check the fill rate against your total fermenter volume — a 7BBL unitank supports roughly 40–45 cases per batch after losses.

Smaller brewpubs sometimes order one instead of three. That usually ends badly. If you produce four beer styles, one tank means you cannot brew the next batch until the current one is kegged and cleaned. Plan for at least one tank per core style, plus a brite or two.

Common Questions

Can I use the same tank for fermentation and carbonation?
Yes, provided it\’s pressure-rated and has a carbonation stone port. Allow extra headspace — fill to 75–80% on high-krausen strains.

What chiller size do I need?
Plan for roughly 1 HP of glycol chiller capacity per 7BBL tank in active fermentation, more if you stagger crashes.

Do I need a separate CIP port?
Yes. Sharing the racking port for cleaning leads to dead legs and buildup. We weld a dedicated 1.5\” CIP port with a rotating spray ball.

304 or 316L?
304 covers most beer production. Go 316L for sour programs, high chloride water, or prolonged storage of finished product.

Before You Request a Quote

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