How much salt you really need

Sauerkraut, kimchi, fermented cucumbers, olives, brined meat: every recipe gives a salt percentage, but not every recipe says what it should be calculated on. The difference is not a detail. Calculating 3% on the water or on the total weight of water and food leads to different amounts of salt, and to a different final product. This calculator shows both versions, the concentration the food actually reaches and the amount in teaspoons.

It works for any recipe and any cuisine in the world: all you need is to weigh the food and the water.

How the calculation works

You enter the weight of the food, the weight of the water (zero for dry salting), the salt percentage and how many grams a teaspoon of your salt weighs.

• Equilibrium method: salt = (food + water) × percentage. This is the amount that brings everything, food included, to the chosen percentage.
• Water-only method: salt = water × percentage. This is the method of many traditional recipes.
• Final concentration: with the water-only method, the salt divided by the total weight, that is the salinity the food reaches once salt and water have spread out.
• Grams per kg: the equilibrium salt per kilo of food.

A litre of water weighs about a kilo, so you can enter millilitres as grams.

Equilibrium or water-only: the difference

Over time, salt and water spread between the brine and the food until the concentration is uniform. With the water-only method the salt is calculated on the liquid alone, but it then dilutes into the water contained in the food too. The table uses a kilo of vegetables and a litre of water.

With equal weights of food and water, the water-only method halves the real salinity: a "5%" brine brings the food to 2.5%. Neither method is wrong, but they must be compared like for like: if a recipe was written with the water-only method, making it with the equilibrium method will make it saltier.

More food, bigger difference

When the jar is packed with vegetables and there is little water, the gap between the two methods grows. The table uses a kilo of food and half a litre of water.

Here a "2%" brine brings the food below 1%, a low salinity for many lactic fermentations. The equilibrium method gives a predictable result whatever the ratio of food to water, which is why many fermenters prefer it.

The most common percentages

Recipes vary a lot between traditions and countries, but some ranges come up often. The values are indicative.

Dry salting

For sauerkraut and similar preparations no water is added: the salt is massaged into the vegetables, which release their own liquid. In this case enter zero as the water weight: the calculator applies the percentage to the food weight alone, which is also how these recipes are usually written.

Grams and teaspoons

The same teaspoon holds very different weights of salt depending on the grain: about 6 grams of fine salt, less of coarse or flaky salt, which leaves more air between the crystals. For brines and ferments it is best to weigh with a scale; teaspoons are a quick check. If you use a salt other than fine, weigh a level teaspoon once and enter the value.

The four bands of the verdict

• Below 1.5%: light salting, better suited to seasoning than fermenting.
• 1.5% to 2.5%: the band of many classic ferments, such as sauerkraut and kimchi.
• 2.5% to 5%: firm brines, for cucumbers and crunchy vegetables.
• Above 5%: strong brines, more for preserving than for fermenting.

Safety and good practice

Use salt without anti-caking agents or added iodine if the recipe says so, because in some cases they can cloud the brine or slow fermentation. Keep the food fully submerged in liquid, work with clean containers and follow the recipe's times and temperatures. If coloured moulds, unpleasant smells or slimy textures appear, do not eat the product. For long-term preserves and for people with particular health needs, follow your country's official food-safety guidance.

Limits of the calculator

The calculation assumes that at equilibrium salt and water spread evenly, and counts the water inside the food as part of its weight. It does not account for salt already present in the ingredients, other liquids such as vinegar or wine, or water that evaporates. It is a tool for calculating quantities, not a recipe or a guarantee of food safety.

Frequently asked questions

How do you calculate salt for a brine?

With the equilibrium method: food weight plus water weight, multiplied by the percentage. With a kilo of vegetables, a litre of water and 2%, you need 40 grams of salt.

What is an equilibrium brine?

It is a method in which salt is calculated on the total weight of food and water, so that at the end of the process everything, food included, reaches the chosen percentage.

How does it differ from the water-only method?

The water-only method calculates salt on the liquid alone. The salt then dilutes into the water in the food too, so the real salinity is lower than the one written in the recipe.

How much salt for sauerkraut?

Many recipes give about 1.5–2.5% of the cabbage weight, dry-salted: for a kilo of cabbage, about 15–25 grams of salt.

How much salt for fermented cucumbers?

Many recipes use brines around 3.5–5%. Remember to check whether the recipe calculates the percentage on the water or on the total weight.

How do I enter dry salting?

Enter zero as the water weight: the calculator applies the percentage to the food weight alone.

How many grams does a teaspoon of salt weigh?

About 6 grams for fine salt, less for coarse or flaky salt. For precise results it is best to weigh salt on a scale.

Can I enter millilitres instead of grams?

For water, yes: a litre weighs about a kilo. For brines with vinegar or wine the weight is similar but not identical.

What salt should I use?

Many fermentation recipes recommend salt without anti-caking agents or added iodine, which in some cases can cloud the brine or slow fermentation.

What happens with too little salt?

Below about 1.5%, many recipes warn that lactic fermentation is less protected against moulds and unwanted bacteria. The calculator flags the low band.

Does the calculator account for salt already in the ingredients?

No: it only counts the salt you add. Already salty ingredients, such as some seasonings, raise the final salinity.

Does the calculator guarantee the preserve is safe?

No, it calculates quantities. For long-term preserves, follow your country's official food-safety guidance and do not eat products with moulds, bad smells or abnormal textures.