Until lemons were introduced to the Mediterranean during the Crusades, virtually every household with access to grapes would make verjuice from the unripened grapes that were thinned before the harvest, employing the sour juice as a flavour enhancer and acid note in cooking.
The process of thinning happens at veraison, when the plant stops putting energy into leaves and starts to create sugars in the fruit. These days, the thinned grapes are usually left to go back into the ground, but it is incredibly simple to turn them into verjuice. Just blend them up, strain off the liquid and leave it for a few hours in a cold place until the sediments settle.
I was lucky enough to be at Rippon, the biodynamic vineyard of my friends the Mills family, as they were thinning the vines, so I collected a basket of unripened grapes for homemade verjuice. As verjuice ferments quickly, I froze the excess in sachets to have on hand throughout the year. Aside from the satisfaction of making something out of nothing, I have found verjuice to be an indispensable condiment that works across sweet and savoury dishes. You can equally drizzle it over sliced fruit with a sprinkle of sugar, or over oysters with a sprinkle of ground pepper.
I use verjuice to deglaze the pan after cooking meat, seafood or chicken, often adding a handful of green peppercorns or a spoonful of fruit jelly to instantly make a vibrant sauce. A splash in a tray of hot roasted vegetables or a pot of mashed potato is sensational.
Because its flavour is so mild you can use a lot more verjuice than you might lemon juice or vinegar – I like to cook a whole chicken in a couple of cups of verjuice. On the sweet side, it makes a lovely jelly, can be used as a spritzer with ice and soda, and is gorgeous for poaching pears and peaches. Now I have discovered its lovely soft acidity I don’t want to be without it.