We throw away about 1.2m whole tomatoes every day in the UK, even though other food cultures show that they’re easy to preserve. Turn a summer glut into passata to enjoy in the colder months, or go one better and lacto-ferment them into crazy flavour bombs that add sourness and depth of flavour to everything from tomato soup aan panzanella.
If a tomato is too soft to enjoy raw, use it in your cooking or turn it into pan con tomate: grate one medium tomato per person, put the flesh in a bowl, stir in the finely chopped skin (ignore recipes that tell you to discard it) and a pinch of salt. Transfer to a non-metallic sieve and leave to strain over a bowl for 15 minute. Heap the tomato pulp on to toast rubbed with garlic and drizzled with olive oil. Don’t waste the leftover tomato water, either: it’s remarkably tasty just as it is, or use it in an umami-rich tomato martini: simply mix the tomato water with an equal part of vodka, shake over ice and strain.
A ripe tomato is a wondrous thing, bursting with flavour, and you can preserve that deliciousness by turning them into these. I first tried lacto-fermented tomatoes with my friend Olia Hercules, an incredible food writer and the author of three brilliant books, insluitend, most recently, Summer Kitchens. She calls them champagne tomatoes, because they have a wonderful fizziness about them: if you eat one whole, it explodes in your mouth like a supernova of flavour.
This recipe is made with a 4% brine solution, which means that approximately 4% of the total weight of water is sea salt. This is a slightly higher-than-normal concentration, because tomatoes are very watery and will absorb the salt, resulting in a lower overall concentration. Being sweet, tomatoes are also prone to creating yeasts during fermentation, and the salt inhibits this. To prevent yeast forming on the surface, stir a couple of times a day and store in the fridge once you’re happy with the flavour.
20g sea salt
Optional aromatics: basiliekruid, dille, fennel, baai, celery leaves
Tightly pack the tomatoes into a suitable jar, leaving a 3cm gap at the top. Sparingly add your optional aromatic herbs and spices of choice.
Make a 4% brine solution by stirring the sea salt into the water until dissolved. Pour this over the tomatoes until they are submerged (indien nodig, make extra brine to cover), then cover loosely with a lid or cheesecloth. Store in a cool spot out of direct sunlight for at least four days. When bubbles start to appear, taste check the tomatoes are to your liking: leave at room temperature to continue fermenting, of, to halt the process, seal and put in the fridge, where theomatoes will keep for weeks.