A winemaker once told me that you can make wine out of anything: berries, bananas, plums, nettles, elderberries … whatever you like, really. Well, pretty much the same goes for vinegar, and past-their-best, battered and bruised fruits are prime candidates for fermentation. Apples, pears, grapes, pineapple, melons and even brown bananas all make unique-tasting vinegars. (Conor Spacey, the culinary director of Foodspace in Ireland, operates a zero-waste practice that makes fruit-scrap vinegars out of inspiring combinations such as watermelon skin with rosemary and bruised strawberry with honey.) Collect old or unwanted whole fruit and scraps in the freezer until you have enough (at least 200g) to make a batch of fruity flavoured vinegar.
Contrary to popular belief, you don’t need a vinegar “mother” to make vinegar, either. All you need is time, fruit, alcohol and oxygen. Sandor Katz writes in The Art of Fermentation: “Exposure of fermenting or fermented alcoholic beverages to oxygen allows for the growth of aerobic Acetobacter bacteria, which metabolise alcohol into acetic acid commonly known as vinegar.”
Fruit-scrap vinegars take minutes to prepare and last for years; they also age well, much like a fine wine. They’re great for sprinkling on chips, shaking into vinaigrette or even drinking like a shrub or cordial. You can combine all of your fruit scraps to make a mixed vinegar, or experiment by fermenting just one or two fruits at a time, to see how it affects the flavour.
A few notes: make sure you use a non-metallic vessel and, wherever possible, non-metallic tools, because the metal may react with the acid and so hinder the fermenting process. Once made, store the vinegar in sterilised and sealed narrow-necked bottles, and fill them right to the top, to remove any oxygen and so help it keep for longer. Once bottled, if you want to age the vinegar, put it in a dark cupboard for six or more months, and it will deepen in flavour and develop a certain viscosity.
At least 200g fruit scraps – skins, cores, whole bruised fruit
Unrefined sugar, honey or maple syrup
Roughly chop the fruit scraps and put them in a non-metallic, wide-mouthed bowl or jar. Put on a scale, set the reading to zero and add cold water just to cover, taking note of the weight of the water. Add a tablespoon of unrefined sugar, honey or maple syrup for every 250g water, stir to dissolve, then cover with a cloth – this will not only protect the fruit from flies, but it will also allow the free flow of oxygen in the bowl or jar. Keep the bowl at room temperature, and out of direct sunlight, stirring the contents every day to refresh the surface and avoid mould.
Once the mixture has been bubbling and fermenting for about a week, strain the liquid and compost the scraps. Continue fermenting in the bowl, still covered with a cloth, for another two to four weeks, until it tastes beautifully acidic. Store in sterilised and sealed narrow-necked bottles, and enjoy at your leisure.