Brine
Brine calculator
The formula: salt (g) = water (g) × brine % — 1 litre of water (1,000 g) at 2.5% takes 25 g of salt. Enter any volume and percentage; we return the salt mass in grams and teaspoons for the common grains.
Brine calculator
For submerged vegetables (cucumbers, peppers, cauliflower, garlic scapes). Salt mass is expressed as a percentage of water mass — NCHFP convention.
1 L of water ≈ 1 kg. 3.5% brine = 35 g salt per litre.
Brine percentages — the working range
- 2.5–3.0% — half-sour pickles, fresh-pickle cucumbers, pepper mash short ferments.
- 3.5% — standard full-sour pickle starting point, fermented garlic, fermented hot sauce base.
- 4–5% — long-keeper pickles, olive cures, cauliflower and green-bean ferments that sit under brine for weeks.
- 5–6%+ — preserving brines for olives and fish-sauce bases. Lactic activity slows; shelf life extends.
Of the 31 vegetables in the fermentcalc dataset, 24 default to 2.5–3% salt, the highest default is 4%, and no published safe range tops 5%. When in doubt, 3% is the standard half-sour starting point.
What is the simple brine formula?
Salt grams = water grams × brine percentage. Water weighs 1 g per ml, so the arithmetic is direct: 1 litre (1,000 g) at 2.5% is 25 g of salt; 1 US quart (946 g) at 3% is 28 g. Weigh the salt — a teaspoon of fine sea salt and a teaspoon of flaky kosher salt differ by nearly half their mass, which is why the calculator converts per grain instead of assuming one spoon fits all.
How much salt for a quart or a gallon of brine?
| Water | 2.5% | 3% | 3.5% | 5% |
|---|---|---|---|---|
| 1 cup (237 ml) | 6 g | 7 g | 8 g | 12 g |
| 1 quart (946 ml) | 24 g | 28 g | 33 g | 47 g |
| 2 quarts (1.9 L) | 47 g | 57 g | 66 g | 95 g |
| 1 gallon (3.8 L) | 95 g | 114 g | 132 g | 189 g |
| 4 gallons (15.1 L) | 379 g | 454 g | 530 g | 757 g |
So four gallons of brine at 3% — the classic crock-of-pickles batch — takes 454 g of salt, about one pound. Teaspoon equivalents depend on the salt grain; the calculator above converts for fine sea, kosher (Morton and Diamond Crystal) and pickling salt.
Is the percentage measured against just the water, or water plus vegetables?
Against the water only— that is the NCHFP convention and the one this calculator uses. Some recipes instead state salt as a percentage of the total weight, water plus vegetables (common in equilibrium-style methods). The same “2.5%” gives a noticeably saltier ferment under the total-weight convention, and mixing the two up is the most common way a batch ends up over- or under-salted. Self-brining ferments like sauerkraut use a third convention again — salt as a percentage of the vegetable weight, no added water — covered by the dry-salt calculator.
Sources: USDA Complete Guide to Home Canning (2015 rev.); NCHFP fermentation guidance; Linda Ziedrich, The Joy of Pickling. Convention used here: salt mass as a percentage of water mass (NCHFP convention).
The kit the brine math assumes
A short, honest kit for lacto-fermentation. The scale is the one that matters most — everything here is by weight.
- Digital kitchen scale (0.1 g)Salt % is by weight, not volume — a 0.1 g scale is what makes the math above accurate.View on Amazon →
- Glass fermentation weightsKeep vegetables submerged under the brine line so they ferment safely without mould.View on Amazon →
- Airlock fermentation lidsLet CO₂ escape while keeping oxygen out — wide-mouth lids that fit standard jars.View on Amazon →
- Wide-mouth mason jarsThe workhorse vessel for kraut, kimchi and brine pickles — 1 qt and ½ gal sizes.View on Amazon →
- Pickling / fine sea saltPure salt with no iodine or anti-caking agents, which can cloud brine and inhibit fermentation.View on Amazon →
- Stoneware fermentation crockFor scaling past the jar — a water-sealed crock for 5 L+ batches with built-in weights.View on Amazon →
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