This is a recipe by Marco Fortunato, which I started making when my vegetable garden produced loads of cherry tomatoes. It is perfect for keeping the taste of summer for the months to come: it needs a little care, but it is easy to make.
Method
Wash the cherry tomatoes carefully, dry them and prick each one in two places with a toothpick. Wash a jar with an airtight lid and dry it with kitchen paper (personally I don't sterilise jars for fermenting). Put the jar on a scale and note its weight. Fill it with the tomatoes, leaving 3-4 cm of space at the top, and add a few basil leaves. Weigh the tomatoes, subtracting the weight of the jar. Add filtered water to cover them and check the weight of water and tomatoes together (without the jar). Calculate 4% of that weight in unrefined, non-iodised sea salt and dissolve it in the water. Cover the opening with baking paper, close the jar and store it in the pantry.
Especially in hot weather, fermentation may push some water out of the jar. For the first 3-4 days, open the jar once a day to let the gas escape. Then close it and don't open it again for at least 3 weeks.
