Priming sugar options aren't interchangeable gram-for-gram — each ferments differently, and using the wrong conversion factor when swapping between them is a common, avoidable source of an over- or under-carbonated batch.
The same target, three sugars
For an 18.9 L (5 gal) batch at 68°F targeting a standard 2.4 volumes CO2:
| Sugar type | Dose needed |
|---|---|
| Corn sugar (dextrose monohydrate) | 116.7 g |
| Table sugar (sucrose) | 105.0 g |
| Dry malt extract (DME) | 158.7 g |
Check any of these directly by switching the sugar type in the calculator — same batch, same target, three genuinely different weights.
Why the numbers differ
Corn sugar (dextrose monohydrate) is the baseline this site's priming formula is built around — it's the most commonly used priming sugar in homebrewing and the sugar the underlying published formula was derived against.
Table sugar (sucrose) needs less by weight — roughly 90% of the corn sugar figure — because dextrose monohydrate carries a water molecule as part of its own molecular structure that doesn't contribute fermentable mass, while granulated sucrose is essentially pure and anhydrous, so a gram of table sugar delivers more fermentable substance than a gram of corn sugar.
Dry malt extract (DME) needs meaningfully more — roughly 1.36x the corn sugar figure — because DME isn't pure fermentable sugar at all; it's roughly 65-70% fermentable extract by weight, with the remainder made up of unfermentable dextrins, proteins and other malt-derived material that adds no CO2-producing fermentation.
These ratios are the commonly-published John Palmer (How to Brew) priming-sugar-table figures, aggregated and applied through the same calculation as every other priming result on this site — not independently re-derived for each sugar type.
Why using the wrong ratio is a real risk, not just an inconvenience
Substituting one sugar for another using a 1:1 weight assumption, without adjusting for these ratios, produces a real carbonation error — using a corn-sugar weight of DME, for instance, underdoses the batch by roughly 26%, landing meaningfully undercarbonated relative to target. Going the other direction — using a DME-scaled weight of corn sugar — overdoses by a similar margin, which matters far more given the safety consequences: see what happens if I use too much priming sugar for how quickly an over-dosed batch becomes a genuine bottle-safety issue.
The dropdown is the fix
Always select the correct sugar type in the priming sugar calculator rather than reusing a weight calculated for a different sugar — it's a single dropdown, and it's the difference between a correctly-carbonated batch and a meaningfully wrong one from what looks like a minor substitution.