Gravity Correction Calculator: DME, Sugar, Water

To raise the gravity, add the missing gravity points times the volume, divided by the extract potential: 20 L of wort at 1.044 that should be 1.050 needs about 0.34 kg of dry malt extract. To lower it, dilute: 20 L at 1.056 needs about 2.4 L of water to reach 1.050.

How the correction is calculated

Gravity points are the decimal part of the specific gravity times 1000, so 1.050 is 50 points. The total points in the wort (points × volume) stay the same unless you add or remove sugar.

To raise the gravity, add the missing points with an ingredient whose extract potential $P$ you know:

m = \frac{(G_t - G_c) \times V}{P}

where $m$ is the mass to add, $G_t$ and $G_c$ the target and current gravity in points, and $V$ the volume. With $V$ in liters and $m$ in kilograms, $P$ is in points per kilogram per liter (L°/kg). With $V$ in US gallons and $m$ in pounds, $P$ is in points per pound per gallon (PPG). One PPG is about 8.345 L°/kg.

For example, 20 L of wort at 1.044 that should be 1.050 is 6 points short. Dry malt extract, at about 42 PPG (350 L°/kg), needs $6 \times 20 \div 350 \approx$ 0.34 kg. In US units, 5 gallons 6 points short need about 11.4 oz.

To lower the gravity, dilute the wort with water. The final volume is:

V_f = V \times \frac{G_c}{G_t}

For example, 20 L at 1.056 that should be 1.050 becomes 22.4 L, so add 2.4 L of water. Boil or use clean, dechlorinated water.

Inside Foambyte, the recipe studio estimates the original gravity of your recipe, and each batch records the gravity you actually measured.

Reference table

Typical extract potential, and the amount that raises the gravity of 1 L or 1 US gallon of wort by one point
Addition	PPG	L°/kg	g/L per point	oz/gal per point
Dry malt extract	42	351	2.85	0.38
Liquid malt extract	36	300	3.33	0.44
Table sugar (sucrose)	46	384	2.60	0.35
Corn sugar (dextrose)	42	351	2.85	0.38
Honey	38	317	3.15	0.42

Sources

John J. Palmer. How to Brew, Brewers Publications, 2006. Typical extract potentials of malt extracts (chapter 18) and of sugars and honey (table 13), and the PPG to L°/kg conversion; 3rd edition, online version with the author's updates.

Frequently asked questions

When should I correct the gravity?

Ideally before the boil ends or before you pitch the yeast, when additions mix in easily. Measure the gravity of the cooled, well-mixed wort and correct it in the fermenter or, better, in the kettle so the addition is boiled.

Which addition should I use to raise the gravity?

Dry malt extract keeps the beer's malt character and fermentability closest to an all-malt wort. Table sugar and corn sugar ferment completely, so they raise the alcohol and dry the beer out. Honey adds its own flavor.

Why does my extract potential differ from the label?

The values here are typical figures. Malt extracts vary by brand and liquid extract by its water content, and sugars are nearly constant. If your supplier gives a potential, enter it under Other.

Does the calculator account for the volume the addition adds?

No. Dissolved sugar or extract adds a little volume, which slightly lowers the result. For corrections of a few points this is negligible; for large additions, add a little less, mix, and measure again.

Is boiling longer a better way to raise the gravity?

Boiling off water also concentrates the wort, but it takes time, changes the hop bitterness and darkens the wort. Adding extract or sugar is quicker and more predictable on brew day.

Gravity Correction Calculator

Malt extract or sugar to add