American food writer Sandor Katz became the modern godfather of fizzy cabbage after his do-it-yourself book, Wild Fermentation, was published in 2003. Here are his tips for making sauerkraut.
- Chop up a few vegetables on a clean work surface – cabbage, carrot, celery, virtually whatever you like. It will take about a kilogram of vegetables to fill a one-litre jar.
- Salt the vegetables. There's no magic amount of salt – add to taste, or if you're trying to moderate your sodium intake you can use very little. The salt helps pull juice out of the vegetables.
- To get the vegetables juicy quickly, I like to get in there with my hands and spend five minutes squeezing them. This breaks down cell walls and releases juice.
- Taste the vegetables to make sure you like the amount of salt – remember, it's always easier to add salt than subtract it. You can add all kinds of other seasonings, too. Traditional ones like caraway, chilli and juniper berries, or make a curry-flavoured kraut. Let your imagination run wild.
- Once the vegies are nice and juicy and salted, you can pack them into a suitable vessel. For first-time fermenters it can just be a clean glass jar – the wider the mouth, the easier the pack. Stuff the vegetables in so they're submerged under their own liquid. Sometimes, if I'm using cabbage, I'll take one of the outer leaves with a big spine and use it like a spring to make sure I can hold everything under the brine. You could also use marbles or other little weights to hold the vegetables down.
- When the vegies are submerged, it's just a matter of storing and waiting. Pressure will build up in the jar and needs to be released daily by loosening the lid, especially during the first few days when fermentation is the most vigorous. In a warm environment, the metabolism of organisms is faster, so they become acidic faster. In cooler weather it's slower, but there's no fixed amount of time.
The big question is what kind of flavour you like. A super sour flavour takes longer to achieve, while a milder flavour is quicker. It's best to wait three or four days for a sauerkraut to get started and then taste it at intervals. When you get to a point of saying "Wow, the flavour's strong, I don't think I want it to get any stronger", then you can transfer the sauerkraut to a fermentation-slowing device. Most people have one at home and it's called a refrigerator.