Pickle calculator
How much salt your jar is asking for
Say what you are fermenting and the calculator gives you the salt in grams, inside the range the sources support. It always shows both readings of the same brine, over the jar and over the water, because that is where the books disagree and where most of the mistakes happen.
Whole vegetables submerged in salted water, fermenting.
What to weigh
- Salt
- 40.0 g
- Vegetables
- 1.000 kg
- Water
- 1.000 kg
- Total in the jar
- 2.000 kg
- Time in the source
- 5–90 days
- Temperature
- 10–21 °C
Salt over the jar
Recommended range: 2% – 3%
Carvalhaes & Andrade, p. 198, p. 199 · Redzepi & Zilber, cap. 2, "Salt Sufficiently", cap. 2, "Lacto White Asparagus"Salt over the water
Recommended range: 3.5% – 5%
Katz, cap. 3, "Tabela de proporções de sal", cap. 5, "Picles azedos", cap. 5, "Kimchi"The same amount of salt has two names. Measured against the whole jar it is the salinity the product settles at; measured against the water it is the strength of the brine on day one. Switching here does not change the recipe, only how it is described.
Carvalhaes & Andrade, p. 211, p. 212, p. 196, p. 48 · Katz, cap. 5, "Quanto tempo deixar fermentando?"Before you close the jar
Fermenting is safe when a few conditions are respected. These are not finishing touches.
The target is pH below 4.6
That is the line where dangerous bacteria stop multiplying. A ferment that is working gets there on its own in the first few days, turning sour and smelling of pickles, not of rot.
Carvalhaes & Andrade, p. 47 · Redzepi & Zilber, cap. "Primer" — "Cleanliness, Pathogens, and Safety"Everything submerged, always
Whatever sits above the brine will mould. Use a weight, a whole leaf or a water-filled bag to keep the vegetable under.
Katz, cap. 5, "Comprimir" · Carvalhaes & Andrade, p. 197Kahm is not mould
A thin, smooth white film on the surface is Kahm yeast: harmless, just lift it off. Fuzzy, coloured or velvety patches are mould, and that batch goes in the bin.
Katz, cap. 5, "Bolores e leveduras na superfície" · Carvalhaes & Andrade, p. 201Where the botulism risk actually lives
Not in fermentation, which is acidic by nature. The risk is in preserves that neither ferment nor get acidified, sealed away from oxygen: badly processed palm hearts, raw garlic in oil. If a preparation neither ferments nor takes acid, it is not safe at room temperature.
Carvalhaes & Andrade, p. 18 · Katz, cap. 5, "Os fundamentos do kraut-chi"Fridge, not pantry
This calculator sizes fridge preserves. Shelf-stable canning requires heat processing with times and temperatures specific to each food, which do not fit in a ratio calculator. Follow official guidance for that.
Carvalhaes & Andrade, p. 202, p. 203
Temperature and time
Fast, 21 to 28 °C
Ready in days, with a straighter acidity. It is how Noma works, with temperature control.
Slow, 10 to 21 °C
Weeks rather than days, more complex flavour and more room for error. It is what Katz and Brazilian Way Fermentation recommend at home, and in a warm climate it means hunting for the coolest spot in the house.
How the calculation works
Fermenting a vegetable is a contest: lactic bacteria have to take over before anything else does. Salt is what tilts it, because they tolerate a salinity their competition does not. That is why the salt percentage is not seasoning: it is the control variable.
The confusing part is what the percentage is measured against. One jar holding 40 g of salt, 1 kg of cauliflower and a litre of water can be described as 2% or as 4%, and both are correct: the first counts the whole contents, the second only the water. The calculator always shows both, because this is exactly where a recipe from one book becomes double or half the salt when read with the other book’s ruler.
In dry salting no water is added: the salt draws liquid out of the vegetable, so the percentage you apply is already the final salinity. And in a vinegar pickle none of this applies, because it does not ferment. What preserves it is the acid you add, and the question becomes how much of the liquid has to be vinegar.
Where the sources disagree
The three works arrive at a similar product by different routes. Wherever a choice had to be made, it is spelled out.
| Topic | What each source says | What the calculator does |
|---|---|---|
| What salt is measured against | Katz measures against the weight of the water (5% for cucumber pickles). Noma and Brazilian Way Fermentation measure against the total weight of the jar, vegetables included (2%). | The default is 2% of the whole jar, with a switch to see and use the Katz method. Measuring the total is more reproducible because it describes the product at equilibrium; Brazilian Way Fermentation shows on p. 199 how measuring only part of the contents delivers half the salt you intended. |
| Fermentation temperature | Noma ferments at 28 °C and counts days. Katz and Brazilian Way Fermentation prefer 10 to 21 °C and count weeks. | Both regimes are offered, each with its own timing. This is not a technical disagreement but a different goal: speed against complexity. In a warm climate the slow route means finding the coolest spot in the house. |
| Minimum acidity for a vinegar pickle | None of the three works sets a floor. Noma gives the 1:1 ratio with 5% vinegar without saying where the limit is. | The floor is 2.5% acetic acid in the covering liquid, which is exactly what that 1:1 ratio produces, backed by official preserving guidance. Food safety does not allow a number without a source, so here the shelf makes room for an official one. |
| White film on the surface | Katz and Noma treat Kahm yeast as harmless, to be lifted off. Brazilian Way Fermentation is more cautious about any surface growth. | We explain how to tell Kahm from mould, and advise discarding whenever there is doubt. With food, the cheap mistake is throwing it away. |
Glossary
- Lacto-fermentation
- Fermentation driven by lactic bacteria, which turn the vegetable’s sugars into lactic acid. The acid is what preserves it and gives a pickle its taste.
- Brine
- Salted water the vegetable sits under. Its strength can be described against the water or against the whole contents of the jar.
- Dry salting
- Salting chopped vegetable without adding water: the salt draws the liquid out and forms the brine. It is the sauerkraut and kimchi method.
- Anaerobic
- Without oxygen. Lactic bacteria work without it and moulds need it, which is why keeping everything submerged decides who wins.
- Kahm yeast
- A thin, smooth white film that sometimes forms on the surface. Harmless and easily removed; not to be confused with mould, which is fuzzy or coloured.
- pH
- A measure of acidity. Below 4.6 dangerous bacteria do not multiply, and that is where a healthy ferment arrives on its own.
- Vinegar acidity
- The percentage of acetic acid printed on the label. Table vinegar is usually 5%, which is what the reference ratio assumes.
- Quick pickle
- A fridge preserve made with acidic liquid, without fermentation. Ready in hours and good for weeks in the fridge, not on the shelf.
Sources for this calculator
The ratios come from the three works below. The safety rules and the minimum acidity for vinegar pickles also draw on official guidance, flagged as such.
The Noma Guide to Fermentation
Redzepi & Zilber · Artisan
cap. 2, "Salt Sufficiently" · cap. 2, "Turning Sweet to Sour" · cap. 2, "Lacto White Asparagus" · cap. 2, "Lacto Plums" · cap. "Primer" — "Salt and Baker's Percentages" · cap. "Vinegar" · cap. 2, "Control the Climate" · cap. "Primer" — "Cleanliness, Pathogens, and Safety"
Brazilian Way Fermentation
Carvalhaes & Andrade · Melhoramentos
p. 211 · p. 212 · p. 222 · p. 223 · p. 241 · p. 242 · p. 233 · p. 237 · p. 238 · p. 206 · p. 208 · p. 209 · p. 210 · p. 224 · p. 225 · p. 217 · p. 218 · p. 239 · p. 240 · p. 198 · p. 199 · p. 196 · p. 48 · p. 47 · p. 17 · p. 201 · p. 197 · p. 18 · p. 202 · p. 203
A Arte da Fermentação
Katz · Tapioca
cap. 5, "Fermentação de molho picante" · cap. 5, "Picles azedos" · cap. 3, "Tabela de proporções de sal" · cap. 5, "Azeitonas na salmoura" · cap. 5, "Salgar com salga seca ou salmoura" · cap. 5, "Kimchi" · cap. 5, "Fermentação lática de frutas" · cap. 5, "Tsukemono" · cap. 6, "Vinagre" · cap. 5, "Quanto tempo deixar fermentando?" · cap. 5, "Bolores e leveduras na superfície" · cap. 5, "Comprimir" · cap. 5, "Os fundamentos do kraut-chi"
National Center for Home Food Preservation
Georgia · USDA
"General Information on Pickling" · "Ensuring Safe Canned Foods" · "General Information on Fermenting"