Which Gas Bottle for a Pizza Oven? (UK Patio Gas Guide)

Propane, in a patio gas bottle. Patio gas is propane sold in a green bottle with a 27mm clip-on valve, in 5kg and 13kg sizes, and it exists precisely because outdoor cooking appliances needed a bottle you could connect without tools.

Both major oven brands build around it. Ooni's UK regulator is rated at 37 mbar on a 1.2m hose and is listed as compatible with the Koda range and Ooni gas burners. Gozney supplies a 37 mbar click-fit regulator with its UK gas ovens, described in its own listings as being for a standard UK LPG patio gas bottle. LPG here means liquefied petroleum gas, the family the Health and Safety Executive describes as obtainable primarily as propane, butane or a mixture of the two.

So the oven, the regulator and the bottle were designed as one system. If you buy the bottle the regulator was made for, the job takes about ten seconds and no spanner.

Two of those three are the same gas. Patio gas and red-bottle propane are both propane; what separates them is the valve on top, and therefore the regulator that fits.

Patio gas uses a 27mm clip-on regulator. You push it down onto the valve until it clicks, and that is the whole procedure.

Standard propane in the red bottles uses a POL fitting, a screw-in connector with a left-hand thread that you turn anti-clockwise into the bottle and tighten with a spanner. It is the older arrangement, still common on larger cylinders, and it is why a garage-forecourt red bottle will not accept the clip-on regulator in your Ooni box.

Butane is a different gas in a blue bottle, and Calor, the UK's largest bottled-gas supplier, splits its fittings by size: the 4.5kg screws on with a sealing washer, while the 7kg and 15kg take a 21mm clip-on. A butane regulator will not fit a propane bottle and a propane regulator will not fit a butane one, which is a deliberate safety feature rather than an inconvenience.

If you already own a red propane bottle for something else, you do not have to buy patio gas. Buy a POL regulator rated at 37 mbar instead and the same gas feeds the same oven. You just lose the tool-free connection.

Because of where its boiling point sits. The gas in the bottle is a liquid under pressure, and it only reaches your burner by boiling off into vapour. Butane boils at roughly minus 1 to plus 1 degree Celsius. Propane boils at about minus 42 degrees.

That gap is the entire argument. On a still January evening a butane bottle sitting on a cold patio is close to the temperature at which it simply stops producing vapour fast enough, and the effect gets worse as the bottle empties and the remaining liquid cools further through evaporation. The symptom is a flame that starts fine and then sags halfway through a session, usually just as the stone is finally hot.

Propane keeps vaporising far below any temperature a British garden will reach. It is the standard for outdoor cooking here for that reason and no other.

The 5kg is the sensible starting point for most people. It is light enough to carry one-handed and to lift into a shed or a garden store, and it fits under or beside a folding oven table without dominating the space. If the oven lives on a balcony or a small patio, or gets put away after every use, this is the one.

The 13kg makes sense when the oven has a permanent home and you cook often. You are refilling a third as often for a bottle that is heavier to move and needs somewhere sensible to live outdoors between sessions. Households that do pizza most weekends through the summer tend to end up here.

One practical detail that catches people out: the regulator is the same for both. A 27mm clip-on fits the 5kg and the 13kg patio gas bottle alike, so stepping up a size later costs you nothing but the bottle.

Space is worth thinking about before you buy rather than after. If you are working with a compact patio, our guide to pizza ovens for a small patio or balcony covers where the bottle has to go as well as the oven.

A 37 mbar propane regulator, in both cases, because that is the UK supply pressure for propane appliances.

Ooni sells the same part separately as a 37 mbar regulator with a 1.2m hose, listed for the Koda range and its gas burners. Gozney's UK listings for the Arc and Roccbox gas burner describe a 37 mbar click-fit regulator for a standard UK patio gas bottle. In practice, if you bought the oven from a UK retailer, the correct regulator is already in the box and you need only the bottle.

Three things are worth checking before you assume a spare or second-hand regulator will do:

• Pressure. It must be 37 mbar. A 28 or 30 mbar butane regulator will not run the oven properly.
• Fitting. Clip-on 27mm for patio gas, POL screw-in for a red propane bottle. These are not adaptable to each other.
• Hose condition. Rubber gas hose perishes. Cracking, hardening or a date stamp well in the past all mean replace it rather than risk it.

Model-specific guidance always beats a general rule here. The data plate on your oven states its rated pressure, and both brands publish the figure for each model. If you are still choosing between models, our Ooni Koda 2 review and Gozney Arc review cover how each one behaves once it is lit.

Longer than most first-time owners expect. The arithmetic is straightforward if you work from the energy in the bottle rather than from guesswork.

Propane releases roughly 50 megajoules of heat per kilogram when it burns, which is about 13.9 kWh. Portable gas pizza ovens sit broadly in the 5 to 10 kW range at full flame, and the exact figure for your model is on its data plate. Take a burner running flat out at 8 kW: that is 8 kilojoules a second, or roughly 0.58 kg of propane an hour.

On that basis a 13kg bottle holds something in the order of twenty hours of full-flame cooking, and a 5kg bottle around eight. Divide by however long your sessions run.

The real number is usually better than that, because almost nobody runs flat out for an hour. A normal session is fifteen to twenty minutes of preheat at full gas, then a lower setting between bakes while the stone recovers, then off. Flat-out arithmetic is the floor, not the expectation.

Per pizza, that puts gas among the cheapest things on the table. The flour, the mozzarella and the good tin of tomatoes all cost more than the fuel that bakes them.

You swap it. Consumer gas bottles in the UK are not filled at the point of sale; they are exchanged. You take the empty to a stockist, hand it over, and walk out with a full one of the same type, paying for the gas rather than for the steel.

The bottle itself is not sold to you outright either. Suppliers such as Calor use a cylinder refill agreement, where you pay a refundable deposit on your first bottle and reclaim it if you later return the empty for good. That first purchase therefore costs more than every subsequent swap, which surprises people who priced the refills and not the entry.

Two practical consequences follow. First, keep the paperwork from that first purchase, because reclaiming the deposit later depends on it. Second, stick to one bottle type once you have chosen. A patio gas bottle exchanges for another patio gas bottle; turning up with a blue butane bottle to swap for a green propane one is a different transaction.

Stockists are widely spread, covering garage forecourts, garden centres, hardware shops and caravan dealers, and each supplier publishes its own stockist finder. Worth checking where your nearest one is before the bottle runs out mid-session rather than after.

Outdoors, upright, and away from anywhere gas could pool. The Health and Safety Executive's guidance on LPG makes the reason plain: it is flammable and heavier than air, so that it will settle and may accumulate in low spots, where it can present a fire, explosion or suffocation hazard. That is why a cellar, an under-stairs cupboard or a sunken patio corner is the wrong place for a bottle, and why the open air is the right one.

The same guidance notes that a powerful odorant is added to LPG so that it is easily detected. Trust your nose. A smell of gas around a connection means turn the bottle off at the valve and investigate before lighting anything.

The connection routine itself is short:

• Connect and disconnect outdoors, with no naked flame or cigarette nearby.
• Check the regulator matches the bottle before forcing anything. Clip-on fittings click; POL fittings turn anti-clockwise and take a spanner.
• Turn the gas off at the bottle valve, not just at the oven dial, when you finish cooking.
• Store the bottle upright so the valve stays in the vapour space, and keep spares outdoors too.

Where the oven itself stands matters as much as where the bottle does. Both manufacturers set minimum clearances from combustible material, and those figures differ sharply between models, which we cover in the guide to putting a pizza oven on decking or a wooden table.