🫙 Fermenting at home checklist

Salt and submersion do almost all the safety work here. Get the ratio right and keep everything under the brine, and this is far harder to get wrong than people assume.

22 items

1. Kitchen scales that weigh to the gramThe salt ratio is worked out by weight, not by eye — a tablespoon of salt varies more than expected.
2. Non-iodised saltIodine and anti-caking agents in table salt can hold back the fermentation itself. Use sea salt or a dedicated pickling salt instead.
3. Fermenting jars with an airlock or a loose-fitting lid×3Gas needs somewhere to go. A tightly sealed jar with no give can build enough pressure to crack.
4. Weights to keep everything under the brine×3This is most of the safety work. Anything poking above the liquid is exposed to air, and air is where mould starts.
5. A large non-reactive bowl for the initial salting and mixing
6. Cabbage, radish or whatever the recipe's built around, as fresh as possible
7. Garlic, ginger and chilli, for a kimchi-style ferment
8. Filtered or dechlorinated water, if the tap water is heavily treatedChlorine is there to kill bacteria, including the ones this whole process depends on.
9. A cloth or loose lid to cover while gas escapes, before sealing properly
10. Somewhere cool and out of direct light for the first fermentA worktop in full sun ferments too fast and unevenly. A cupboard or a cool corner is better.
11. Labels with the date and what's in the jar
12. Checking daily for the first weekPress anything that's floated back under the brine, and check nothing's grown on top.
13. Knowing mould from kahm yeast
14. Kahm yeast: thin, flat, white, harmless — skim it off and carry on
15. Mould: fuzzy, often blue, green, pink or black — bin the whole jar, not just the top
16. If genuinely in doubt, treat it as mould
17. Tasting to judge when it's done, not just the calendarA few days to a few weeks, depending on temperature. Taste it rather than trust a fixed number from a book.
18. Moving it to the fridge once it's fermented enoughCold slows the process right down rather than stopping it — this is how it keeps for months rather than days.
19. Kefir grains and milk or sugar water, if fermenting kefir rather than vegetables
20. A sieve kept only for straining kefir grains
21. Hands and equipment washed before every stepFermentation relies on the right bacteria winning. Dirty hands or a dirty jar can tip that balance the wrong way.
22. Never tasting a ferment that smells wrong, to check itSharp and sour is right. Rotten or sulphurous is the sign to stop and bin it, not taste further to be sure.