Lacto-fermentation basics: salt percentage and the equipment that matters

Salt percentage is measured against the combined weight of the vegetable plus any water added, never against the water alone. That distinction matters because most vegetable ferments, sauerkraut chief among them, add no water at all: the vegetable is salted directly, and the salt draws liquid out of the vegetable's own cells through osmosis until there is enough brine to submerge everything. In that case the vegetable's weight is the entire denominator. Only when a ferment does use added water, such as a whole cucumber pickle sitting in a brine rather than shredded cabbage salted directly, does the water weight get added to the vegetable weight before the percentage is applied.

• Dry-salted ferment (sauerkraut, shredded vegetables): percent of the vegetable weight alone, since no water is added
• Brine ferment (whole cucumbers, whole vegetables submerged in liquid): percent of vegetable plus water weight combined
• Example: 1,000 grams of cabbage at 2.0 percent needs 20 grams of salt and nothing else
• Weigh after trimming and shredding, not before, since trimmed weight is what you are actually salting

Two percent is the right default for a first batch of almost anything. The bands below trade speed for margin: a lower percentage ferments faster and tastes milder but leaves less room for error in a warm kitchen, while a higher percentage slows things down and firms up the texture, with less risk of unwanted growth along the way. Five percent is really a brine cure rather than a ferment in the usual sense, used for olives and other vegetables meant to keep for a long time rather than sour quickly.

Salt is selective. Lactic acid bacteria, the organisms that actually drive fermentation and produce the acid that preserves the vegetable, tolerate salt at these concentrations without much trouble. Many of the molds and other organisms that would otherwise spoil a jar of shredded cabbage do not tolerate the same salt level nearly as well, so salting at the right percentage tips the environment in favor of the bacteria you want and against the growth you do not. This is why the percentage is not just about taste: too little salt removes that selection pressure and gives unwanted organisms a real chance to get established before the lactic acid bacteria acidify the batch enough to take over on their own.

Yes. Use plain salt without iodine and without anti-caking agents. Iodine can suppress the fermentation bacteria you are trying to encourage, and anti-caking agents can cloud the brine and settle out as sediment, which makes the jar look like something has gone wrong even when nothing has. Canning salt, pickling salt, and most coarse sea salts sold without additives all work; check the ingredient label rather than assuming, since some fine table salts include both iodine and an anti-caking agent by default.

A scale, something to keep the vegetables submerged, and a lid that lets gas escape without letting air back in. A half gallon crock like Kenley's is the right size for a first batch, roughly one large cabbage, and it comes with weights and a pounder built in. Pickle Pipes turn an ordinary wide mouth mason jar into an airlocked ferment for less money, and stainless fermentation lids are the metal equivalent if you would rather not deal with silicone. Whatever the vessel, a set of glass fermentation weights is what actually keeps the vegetable under the brine, and that single job matters more than any other piece of equipment on this list. For a full head or two of cabbage at once, Kenley's 1 gallon crock holds twice what the half gallon size does in the same water-channel design, and for a batch bigger than that, a two gallon stoneware crock is the point where a real crock starts making more sense than jars. A larger 0.1 gram scale or a basic one gram scale both work for bigger batches where the percentage error from coarser resolution matters less in absolute terms.