I ferment vegetables from the market at the end of my street in a flat with one small balcony, and I write each batch up with the salt weighed to the gram, because a jar that worked is only useful if I can make it again.

Ferncombe is the name of the lane in Devon where my grandmother kept a shed of jars on slatted shelves, and it is the only thing I brought from there that still does any work. I have cooked for a living in England and in Catalonia, and I moved into a third-floor flat in Gràcia in 2019 with a kitchen the width of a corridor and a balcony just deep enough for a chair and six jars. The notebook started in 2021, the summer a jar of peppers pushed its lid off.

Everything here is lacto-fermented or brine-cured vegetables and fruit that behaves like a vegetable, so cabbage, carrots, peppers, beans, cauliflower, turnips, lemons and olives. There is no vinegar pickling beyond the odd note, no fermented drinks and no dairy. The vegetables come from the covered market a few streets up and from the stalls outside it on Saturdays, and the batches follow what those stalls have rather than what a recipe asks for.

Each entry is written from the notes stuck to the jar itself: weight of vegetables, weight of water, grams of salt, the date, the balcony thermometer and what the brine looked like each morning. I am not a microbiologist and do not pretend to be. Where I describe why something happened, I say how sure I am, and where a jar failed I say so and describe it properly.