Pressure Fermenters Explained: Do You Need One?

A pressure fermenter lets you ferment and carbonate your beer in the same vessel, then serve or keg it without it ever touching oxygen. This guide explains what that actually means for your beer, and covers the Apollo range we stock.

What Is a Pressure Fermenter?

A standard fermenter vents CO₂ as it's produced. A pressure fermenter seals it in instead, using a pressure relief valve (PRV) to hold the vessel at a chosen pressure. Two things follow from that:

• Built-in carbonation. By the time fermentation finishes, the beer is already carbonated from its own CO₂, so there's no separate priming or force-carbonating step.
• No oxygen exposure. The beer can be served or transferred to a keg under its own pressure, without ever being open to air. Oxygen is one of the biggest enemies of hop aroma, so this matters most for hop-forward styles like NEIPAs and pale ales.

The Apollo Pressure Fermenters

Both models are a true conical shape in clear, high-strength PET, with a dry hop port, a centralised floating dip tube for clean transfers, a thermowell, built-in handles, a stainless steel stand, and three interchangeable PRVs so you can choose your pressure setting. Each unit is pressure tested before it leaves the factory.

• Apollo 30L Snub Nose – the standard model, ideal for most home brewers moving to pressure fermentation.
• Apollo 30L Unitank – adds a stainless steel plunge valve and collection bottle, so you can dump trub and harvest yeast without disturbing the beer.

Keep temperature stable with the Apollo Pressure Fermenter Jacket, which insulates against ambient swings and works even better paired with a temperature controller.

Do You Need One?

Worth it if…

• You brew hop-forward styles and want to protect the aroma from oxidation
• You want to skip priming or force-carbonating and drink sooner
• You already keg your beer and want a fully closed process from wort to glass

Not essential if…

• You mostly brew malt-forward styles like stouts and bitters, where oxidation matters less
• You're happy bottle-conditioning or force-carbonating separately

A standard fermenter and good process still make excellent beer. A pressure fermenter removes one more variable and speeds up the last step, which is why it's popular with brewers chasing the freshest possible hoppy beer.

Using a Pressure Fermenter

1. Ferment as normal, sealed under the fermenter's own pressure.
2. Dry hop through the dry hop port without opening the vessel to air.
3. Once fermentation and carbonation are where you want them, transfer directly to a keg, or serve straight from the fermenter, under pressure throughout.

See our kegging guide for what to connect it to next.

Frequently Asked Questions

What does a pressure fermenter do?

It ferments beer under pressure instead of venting CO₂, which carbonates the beer as it ferments and lets it be transferred or served without exposure to oxygen.

Do I need a pressure fermenter?

Not essential, but especially useful for hop-forward styles like NEIPAs and pale ales, where oxygen exposure dulls the aroma.

What's the difference between the Snub Nose and Unitank Apollo?

The Unitank adds a plunge valve and collection bottle for dumping trub and harvesting yeast mid-fermentation. The Snub Nose is the standard model without it.

Can I dry hop in a pressure fermenter?

Yes, through the dedicated dry hop port, without opening the vessel or losing pressure.

Does beer from a pressure fermenter still need conditioning?

Less than usual, since it carbonates during fermentation, but most beers still benefit from a short rest to let flavours settle before serving.