Throughout history most humans across the planet didn’t have the luxury to let anything go to waste. Every item, edible or otherwise, was used, reused or reimagined to its full potential. Without industrialization, and what our grocery stores would have us believe are seemingly endless supplies, it wasn’t an option to forget food or to toss and part of it for any reason. In recent years, there has been a growing effort to end food waste, not only in fields, factories, and restaurants but also in our own kitchens. Enter vinegar, perhaps the world’s oldest and most ubiquitous condiment. Fermenting your own vinegar gives you the opportunity to glean enchanting flavored acid from food scraps that were formerly headed to the waste stream. Depending on the ingredients you will have varying degrees of micronutrients in the form of antioxidants and phenolics, but you will never need to buy expensive gourmet or raw vinegars.
Let’s start by understanding the basics of vinegar. Vinegar is acetic acid diluted in water, with trace chemicals and other acids that give different types of vinegar their distinctive character and flavors. Vinegar is the result of a two-part fermentation, the first being ethanol, think of hard cider and wine, for two common table vinegars. The ethanol is exposed to air where acetic bacteria enter and thrive. They consume and convert this ethanol into acetic acid. In the case of scrap vinegars, a sort of country wine is made by adding sugar water to the scraps that is then converted into vinegar. In the recipe below you will see that the fermentations happen simultaneously.
Universal Scrap Vinegar Recipe
Yield: about 2 quarts
You can use any fruit scraps you like with this recipe: strawberries that have been topped with a bit of fruit; cherry pits that have gone through pitting but still retain a lot of juicy fruit bits; the mashed steamed skins and such that come from a steam juicer; the mash after running fruit through a food mill; the fiber that comes out of your juicer after making apple, beet, or ginger juice; tiny, seedy wild rose hips. You get the idea. Besides flavor, the skins and bits of fruit often provide wild yeasts as well as nutrients for any yeast you use. If you are using organic skins and peelings feel free to omit the added yeast, however, I include instructions for adding yeast if using non-organic scraps. Like the pomace left from pressing apples, though, scrap vinegar often needs to be fortified with a sugar source.
The amount of scrap material called for in this recipe may seem unattainable at first glance. Don’t worry: you can collect and store scraps in the freezer until you have enough. I like to use closer to a pound, but there is a lot of leeway. Use what you can gather, and combine ingredients that seem like they’d be tasty together.
½ - 1 pound (225–450 g) fruit/vegetable skins, cores, leftover mash from straining, or basically anything left from a fruit or vegetable project
¾ cup (155 g) sugar, any kind
1 ½ quarts (1.5 L) unchlorinated water, boiled
½ teaspoon (1 g) wine yeast hydrated in {1/4} cup (59 mL) unchlorinated water,
¾ cup (177 mL) raw, unfiltered vinegar starter (make sure it is unpasteurized), or a vinegar mother
Place the fruit and sugar in a sanitized half-gallon jar. Stir in 1 quart of the just-boiled water. Use the remaining water to fill the jar to the neck.
Hydrate the yeast, by sprinkling it over the warm water. Stir gently, and let it sit for 20 minutes.
When the mixture cools to room temperature, add the vinegar starter and optional yeast.
Stir well with a wooden spoon. You want to get some oxygen in the mix. However, make sure the fruit scraps themselves stay submerged, otherwise they can become a host for undesirable opportunistic bacteria.
Cover the jar with a piece of unbleached cotton (butter muslin or tightly woven cheesecloth) or a basket style paper coffee filter. Secure with a string or rubber band, or screw on the ring from the jar over the cloth or filter. This is to keep out fruit flies.
Place on your counter or in another spot that is 75° to 86°F/25° to 30°C.
Stir once a day with a wooden spoon for the first 5 or 6 days, then stir now and then, if you remember. You may see bubbles: that is good.
The ferment will begin to slow down in about 2 weeks. It is time to take out the scraps. When you remove the cover, you may see a film developing on top. It is the beginning of the vinegar mother. Remove and set it aside while you’re straining out the fruit solids.
Transfer the almost-vinegar (and the vinegar mother, if you have one) into a clean jar and cover again.
Check the vinegar in a month, when you should have nice acidity. However, it may take another month or two to fully develop. Test the pH: it should be 4.0 or below.
Bottle the finished vinegar, saving the mother for another batch or sharing with a friend.
Recipe adapted from Homebrewed Vinegar by Kirsten K. Shockey. Used with permission from Storey Publishing.