Infused Fruit Vinegars

My current project is a fresh prune vinegar which got a nice color within a day.

Kurozu is translated literally as “black vinegar.”

It is an aged rice vinegar with amino acids and reported health benefits like improving circulation and digestion. It is not only a summer drink, but I often see it promoted as being healthy during the summer months. Similar to taking shots of apple cider vinegar to ward off colds, some people think it works while others are skeptical.

Fruit infused vinegar, sometimes called kurozu, is a drinking vinegar made from a simple combination of fresh fruit, vinegar, and sugar. It doesn't need to be infused in an aged black vinegar, although it can be purchased that way from some local businesses.

This article goes in depth into the process of making kurozu by the business Kakuida in Kagoshima. 

Of course stores sell infused fruit vinegars, mostly in the sweetened apple cider vinegar flavor. If you are interested to try making fruit infused kurozu, you can try out even small amounts using the fruit you like.

You'll need a container with a lid and a wide enough opening, preferably glass. Choose your favorite seasonal fruit, which shouldn't necessarily have seeds removed. In the case of umesu, the fruit are left intact with only stems removed, the same way ume liquor is prepared. Citrus fruits are generally sliced and have seeds removed.

The sugar is also the same rock sugar used to make fruit infused liquors like umeshu. It's called ice sugar (氷砂糖) in Japanese. Rock sugar and the big glass jars used to make fruit liquors usually come out in the seasonal sections of stores during spring and summer. It should be in the sugar section most of the year. Note that regular sugar and honey work fine if you don't want to bother with rock sugar. I made a lemon honey vinegar recently.

Of course you'll need vinegar. There are a lot of vinegars available in Japan, but you'll want a commercial vinegar. Basic rice vinegar, grain vinegar (above photo), or even apple cider vinegar works, but don't use a seasoned sushi vinegar or something made for cleaning, if you can even find that.

(I have only seen a small 500 ml size bottle of vinegar in Japan. There are inexpensive one gallon (almost four liter) jugs of white cleaning and cooking use vinegar for sale anywhere in the US, so it is strange that's one thing I don't see here.)

With the three ingredients, you'll want to (loosely) proportion them evenly, in a 1:1:1 ratio in your glass jar. Depending on the fruit, your drinking vinegar could be ready in a week. At least once a day, give your jar a little shake, enough to agitate the liquid and ensure the fruit is covered. (If the fruit is floating out of the liquid for too long, it can get moldy.) The rock sugar will start to dissolve soon.

When the vinegar seems infused well enough, you'll want to remove the fruit. It's also a good idea to strain out any little bits of fruit. It should be refrigerated once the fruit is removed and used up in a reasonable amount of time (a month or two?).

Drink the vinegar with water at a 1:4 ratio, adjusting to your taste. It can also be used as a shaved ice syrup or in homemade sauces. The fruit can be eaten too, although you might want to mix it into something sweet.

Stay hydrated out there.