Salt Needed
20.0g
Tsp
3.3
Days
14-21
Jars
2
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Most lacto-fermented vegetables use 2-5% salt by weight. Sauerkraut works best at 2-2.5%, kimchi at 3%, and pickles at 3-5%. Lower percentages ferment faster and produce a tangier result, while higher percentages slow fermentation and keep vegetables crunchier.
Fermentation speed depends heavily on temperature. At cool temperatures (60-65°F), sauerkraut takes 21-28 days. At room temperature (68-72°F), it takes 14-21 days. In warm conditions (75-80°F), it can finish in 7-14 days. Kimchi ferments much faster, often ready in 3-7 days at room temperature.
| Ferment Type | Cool (60-65°F) | Room (68-72°F) | Warm (75-80°F) |
|---|---|---|---|
| Sauerkraut | 21-28 days | 14-21 days | 7-14 days |
| Kimchi | 7-14 days | 3-7 days | 2-4 days |
| Pickles | 7-14 days | 3-5 days | 2-3 days |
| Hot Sauce | 14 days | 7-14 days | 7 days |
Mold grows when vegetables are exposed to air above the brine. Keep all vegetables fully submerged using a fermentation weight or zip-lock bag filled with brine. Use clean equipment, maintain proper salt levels (at least 2%), and keep the ferment at a stable temperature. A thin white film (kahm yeast) is harmless but should be skimmed off.
Dry salting means massaging salt directly into shredded or sliced vegetables to draw out their natural juices, creating the brine. This works best for high-moisture vegetables like cabbage. The brine method dissolves salt in water and pours it over whole or chunky vegetables like cucumber pickles that don't release enough liquid on their own.
Inputs
Result
Massage 20g of kosher salt into 1kg of shredded cabbage until it releases enough liquid to submerge. Pack tightly into quart jars, weigh down, and ferment at room temperature for 2-3 weeks.
Inputs
Result
Dissolve 26.3g salt in 250ml water. Pack whole or halved cucumbers into a quart jar with garlic and dill. Pour brine over cucumbers, weigh down to submerge, and ferment 3-5 days at room temperature.
Salt (g) = Vegetable Weight (g) × (Salt % / 100)For dry salting, salt is calculated as a percentage of the vegetable weight alone. The vegetables release their own liquid when massaged with salt.
Where:
Vegetable Weight= Weight of prepared vegetables in gramsSalt %= Target salt percentage (typically 2-3.5%)Water (ml) = Vegetable Weight (g) × 0.5 | Salt (g) = (Vegetable Weight + Water) × (Salt % / 100)For brine, water is added to cover the vegetables (approximately half the vegetable weight). Salt is calculated as a percentage of the total weight of vegetables plus water.
Where:
Water= Amount of water needed to cover vegetablesTotal Weight= Combined weight of vegetables and waterJars Needed = ceil(Total Volume / (Jar Capacity × 0.8))Jars should be filled to about 80% capacity to leave headspace for brine and expansion during fermentation. Standard jar sizes: pint (473ml), quart (946ml), half-gallon (1893ml), gallon (3785ml).
Where:
Total Volume= Combined volume of vegetables and brine in mlJar Capacity= Volume of the chosen jar size in ml0.8= 80% fill factor for headspace2% salt by weight is the minimum threshold for safe lacto-fermentation—below this, harmful bacteria like Clostridium and E. coli can outcompete beneficial Lactobacillus and cause spoilage or foodborne illness. Above 5%, even Lactobacillus struggles, and fermentation stalls entirely. The sweet spot for most vegetables falls between 2% and 3.5%, depending on the texture and speed you want.
Sauerkraut works best at 2–2.5% salt, which produces a tangy, well-rounded flavor in 14–21 days at room temperature. Kimchi uses 3% to balance the faster fermentation from its higher sugar content. Whole cucumber ferments need 3.5–5% because the brine must penetrate intact skin, and higher salt keeps them crunchy rather than mushy.
Salt type matters. Use non-iodized kosher salt or sea salt—iodine inhibits Lactobacillus growth and can stall fermentation. Fine-grain salt dissolves faster for brine methods, while coarse salt clings better to shredded vegetables for dry-salt methods. By weight, all salt types are equivalent; by volume, coarse kosher salt measures roughly 1.5× the volume of fine table salt for the same weight.
| Ferment Type | Salt % | Method | Room Temp Time |
|---|---|---|---|
| Sauerkraut | 2–2.5% | Dry salt | 14–21 days |
| Kimchi | 3% | Dry salt | 3–7 days |
| Dill Ferments | 3.5–5% | Brine | 3–5 days |
| Hot Sauce | 3% | Dry salt | 7–14 days |
| Curtido | 2% | Dry salt | 1–3 days |
68–72°F room temperature is the ideal compromise between speed and flavor complexity for most lacto-ferments. At this range, sauerkraut takes 14–21 days, developing a balanced tanginess with layered flavor. Cool fermentation (60–65°F) stretches the timeline to 21–28 days but produces deeper, more nuanced results that professional fermenters prefer.
Warm environments (75–80°F) cut fermentation time nearly in half—sauerkraut can finish in 7–14 days—but the rapid acid production creates a sharper, one-dimensional sourness. Kimchi is the exception: its complex ingredient mix (gochugaru, fish sauce, garlic) benefits from faster fermentation because the flavors meld quickly at warmer temperatures.
Above 80°F, fermentation becomes unpredictable. Yeast activity increases, producing off-flavors and excessive CO₂ that can overflow jars. Below 55°F, Lactobacillus becomes nearly dormant. Use a fermentation vessel calculator to plan container sizes that account for CO₂ expansion, especially in warm conditions.
20g of salt per 1,000g of cabbage is the classic dry-salt sauerkraut recipe, and the cabbage itself provides all the liquid needed. Massage the salted cabbage for 5–10 minutes until it releases enough juice to submerge itself when packed tightly in a jar. This method works for any high-moisture vegetable: cabbage, radishes, onions, carrots (shredded), and hot peppers.
The brine method is necessary for whole or chunky vegetables that don’t release enough liquid on their own. Whole cucumbers, cauliflower florets, green beans, and garlic cloves all need a prepared salt-water solution poured over them. The brine formula adds water equal to roughly half the vegetable weight, and the salt percentage is calculated on the combined weight of vegetables plus water.
A 500g batch of dill ferments needs 250ml of water and 26.3g of salt at 3.5% concentration. The total salt is higher than a dry-salt ferment of the same vegetable weight because you’re also salting the added water. This is the most common calculation mistake beginners make—our fermentation calculator handles it automatically for both methods.
Dry-salt method for shredded vegetables (sauerkraut, kimchi). Brine method for whole or chunky vegetables (cucumbers, cauliflower, green beans).
100% of mold problems in lacto-fermentation come from one cause: vegetables exposed to air above the brine line. Lactobacillus thrives in anaerobic (oxygen-free) conditions, while mold requires oxygen. Keep every vegetable piece submerged at all times using a fermentation weight, a zip-lock bag filled with brine, or a plate weighted with a water-filled jar.
Kahm yeast is a thin, wrinkly white film that sometimes forms on the surface. Unlike fuzzy mold, kahm yeast is harmless but can impart a slightly musty flavor. Skim it off with a spoon and ensure better submersion. Kahm yeast is more common in warmer environments above 75°F and in lower-salt ferments below 2%.
Soft, mushy vegetables are the second most common complaint. This happens when salt percentage is too low (under 2%), temperature is too high (above 80°F), or the ferment goes too long. For crunchy results, use 3.5–5% salt, add a grape leaf or oak leaf (the tannins help maintain crunch), and ferment at 65–70°F. Move the jar to the refrigerator as soon as the flavor is where you want it—cold temperatures halt fermentation and preserve texture.
800–900g of shredded cabbage fits into a single quart jar (946ml) when packed tightly, leaving the recommended 20% headspace for brine and CO₂ expansion. One medium head of cabbage weighs about 900g, making a quart jar the perfect single-head batch size. For larger batches, half-gallon jars hold 1,600–1,800g.
Whole vegetables pack less efficiently than shredded ones. A quart jar holds only 450–500g of whole small cucumbers due to the air gaps between pieces. Plan on 1 quart jar per pound of whole vegetables. Wide-mouth jars are strongly recommended for all fermentation—they make packing, weighting, and extracting food much easier than narrow-mouth alternatives.
Fill jars to no more than 80% capacity. Active fermentation produces CO₂ that bubbles through the brine, and some vegetables expand as they absorb liquid. Overflow is messy and wastes brine. For precise vessel planning, the fermentation vessel calculator computes headspace, total weight, and jar count for any batch size.
| Jar Size | Capacity | Shredded Veg | Whole Veg |
|---|---|---|---|
| Pint | 473ml | 400–450g | 225–250g |
| Quart | 946ml | 800–900g | 450–500g |
| Half-Gallon | 1,893ml | 1,600–1,800g | 900–1,000g |
| Gallon | 3,785ml | 3,200–3,600g | 1,800–2,000g |
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Last Updated: Mar 26, 2026
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