How Much Priming Sugar for Cider? (Bottles, PET and Pressure Barrel)
Quick answer
For dextrose, use roughly 1.5 g/L for a light pétillant cider, 4 g/L for medium and 7 g/L for sparkling. Table sugar needs about 10% less. That's 35 g, 90 g and 160 g per 23 litres. Only prime fully fermented, stable cider, and keep sparkling levels to PET, swing tops or a pressure barrel.
Cider is more forgiving than beer when it comes to carbonation, but it's easier to overshoot. It ferments right down to near-zero sugar, so every gram you add at bottling turns directly into pressure. This guide gives you the numbers in g/L, then shows how to apply them to bottles, PET and a pressure barrel.
How the Maths Works
Your cider already holds some dissolved CO₂ after fermentation, around 0.8–0.9 volumes at typical cellar temperatures of 15–20°C. Priming only needs to supply the difference between that and your target. As a rule of thumb:
- Dextrose (glucose monohydrate): about 4.5 g/L adds 1 volume of CO₂.
- Table sugar (sucrose): about 3.9 g/L adds 1 volume, so use roughly 10% less than dextrose.
Dextrose is the usual choice because it ferments cleanly and is easy to dissolve. You can plug your exact volume and temperature into our priming sugar calculator to check the figures below.
Priming Sugar Table: g/L by Carbonation Level
| Style | Target CO₂ (vols) | Dextrose g/L | Table sugar g/L | Dextrose per 23 L |
|---|---|---|---|---|
| Still | ~0.9 (residual only) | 0 | 0 | 0 g |
| Light pétillant | 1.2 | 1.5 | 1.4 | 35 g |
| Medium (gently sparkling) | 1.8 | 4 | 3.8 | 90 g |
| Sparkling | 2.4 | 7 | 6.2 | 160 g |
These are guides, not gospel. A cider kept at 12°C holds more residual CO₂ than one at 22°C, so use the temperature the cider has actually been sitting at. Most traditional British ciders sit between medium and sparkling. Going above about 2.5 volumes is asking for trouble in anything other than proper heavy-duty bottles.
Before You Prime: Check Fermentation Is Finished
- Take hydrometer readings three days apart. They must be identical, usually 0.998–1.000 for a fully dry cider.
- Don't prime if you've back-sweetened with sugar. The yeast will ferment it and you'll get bottle bombs. Back-sweeten with a non-fermentable sweetener, or stabilise first and carbonate by force in a keg.
- Don't prime cider that's been treated with potassium sorbate. The yeast is inhibited and you'll end up with flat bottles.
- Rack off the lees. A fresh dose of yeast isn't usually needed, but a very clear, cold-crashed cider may carbonate slowly. A dose of Gervin GV13 Cider Yeast doesn't hurt in that case, though it usually isn't necessary.
Bottling: Swing Tops and Glass
Dissolve your sugar in a little boiled water, cool it, and stir it gently into the bulk cider before bottling, so every bottle gets an even dose. Per 500 ml bottle, the table works out at roughly 0.75 g (light), 2 g (medium) and 3.5 g (sparkling) of dextrose.
500ml swing top bottles and 750ml swing tops are great for cider, and the clear glass shows off the colour. The amber versions (500ml) are not listed here, so check our range, or stick to the clear ones. Keep to medium or below in swing tops unless the bottles are marked as rated for sparkling drinks, and always check seals and rubber washers for wear.
Priming in Carbonation Drops
If you don't want to weigh sugar, Mangrove Jacks carbonation drops are a dextrose-based option that drops straight into each bottle. They're sized for beer-level carbonation, so for a medium cider, follow the pack guidance and don't double up. Drops are quick but less adjustable than the g/L method.
PET Bottles: The Safe Way to Test
PET bottles are a favourite for cider because you can feel the carbonation. Coopers PET bottles and caps (24 x 500ml) take the same priming rates as the table. Fill one PET bottle alongside your glass bottles. When it feels rock hard (usually after 7–14 days at room temperature) the rest are ready to chill. Squeeze it, and if there's still give, wait.
Pressure Barrel: Use the Same Rate
A pressure barrel such as a King Keg needs the same g/L rate, but make sure you fill to the recommended level and don't over-prime. For a 23-litre fill, 4 g/L (about 90 g dextrose) gives a medium cider; 7 g/L is a proper sparkling one. If you've made a lot of cider and are about to serve it, see our King Keg top tap and pin valve cap for spare parts. Vent a little at the pin valve after a few days if the barrel is over-firm, and let it condition for 1–2 weeks.
Conditioning and Troubleshooting
- Condition warm: 18–22°C for 2 weeks, then chill for at least 48 hours before opening.
- Flat after 3 weeks: the room is too cold, the cider is sorbated, or the yeast has dropped out.
- Gushing: fermentation wasn't complete, or the dose was too high. Chill it fully and open slowly.
Shop at BrewCo
Everything you need to carbonate cider safely is at BrewCo in Halifax, West Yorkshire: