Tool · Ferment
Fermentation salt calculator
Brine strength is a percentage of weight, not a number of spoons. Weigh what is going in the jar, pick a percentage, and get the grams of salt.
Salt per kilogram and per pound
Total contents means chiles, vegetables and water together. Multiply the table by the weight of your batch.
| Salt % | Per 1,000 g of contents | Per 1 lb of contents |
|---|---|---|
| 2% | 20 g | 9.1 g |
| 2.5% | 25 g | 11.3 g |
| 3% | 30 g | 13.6 g |
| 3.5% | 35 g | 15.9 g |
Which percentage
For fermented hot sauce, this site works in a 2.5% to 3.5% band. Below about 2% the safety margin is gone; above about 5% the lactobacillus itself is inhibited and the ferment stalls. The fermentation guide covers the reasoning, the first week of a ferment, and how to tell kahm yeast from mould.
Food safety
Salt is one of three conditions. Keep every piece of solid under the brine with a weight, and let the pH fall; see the fermentation guide. A finished ferment is a refrigerator product. A shelf-stable hot sauce needs a tested process such as the NCHFP chile salsa on ourtested canning page. General reference: NCHFP, General Information on Fermenting.
Use it on a real recipe
What this calculator assumes you own
A gram scale, non-iodized salt, and a way to hold everything under the brine.
Digital Kitchen Scale, 11 lb, g/ozMust have
Fermentation brine is a percentage of weight, measured in grams rather than spoons. Without a gram scale you are guessing at the one number that determines whether the ferment is safe.
Canning & Pickling Salt, 4 lb ×4Must have
Table salt carries iodine and anti-caking agents. Iodine suppresses the lactobacillus you are trying to cultivate and the anti-caking agent turns your brine cloudy grey.
Glass Fermentation Weights, 4-PackMust have
Anything floating above the brine will mould. A glass weight holds the chile mash under the surface for three weeks without you touching it, which is the whole job.
Complete Mason Jar Fermentation KitMust have
Fermentation is anaerobic. An airlock lets CO₂ out without letting oxygen in, which is the entire difference between a clean lacto-ferment and a jar of kahm yeast and mould.
Hydrion Short-Range pH Strips, 0.0–6.0
The budget answer, and a usable one: a 0–6 range in 0.5 steps tells you whether a ferment has crossed 4.6. Universal 1–14 strips can't, which makes them useless for this job.
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Questions people actually ask
How much salt do I need for a fermented hot sauce?
Weigh everything going in the jar, chiles, vegetables and any water, and multiply by the percentage. At 3%, 1,000 g of total contents takes 30 g of salt. This site works in a 2.5% to 3.5% band for hot sauce; the fermentation guide explains why.
Do I count the water in the weight?
Yes. The brine percentage is salt divided by the total weight of vegetables plus water. For a dry-salted mash with no added water, leave the water field at 0.
Can I measure salt by the spoonful instead?
No. Crystal size changes the weight in a spoon by up to a factor of two between table, kosher and sea salt, so a spoon measurement can land well outside the target percentage. Weigh it on a gram scale.
What if I already added salt and am not sure of the percentage?
Use the second box: enter the grams of salt you added and the calculator returns the resulting percentage and where it sits against the 2% to 5% range used on this site.
Does the right percentage make a ferment shelf-stable?
No. A correct brine percentage is one of three conditions for a safe ferment, alongside keeping everything under the brine and letting the pH fall. Shelf storage needs a tested canning process, and a fermented recipe you wrote is not one. Refrigerate finished ferments.