Plum vinegar is not just vinegar made from plum juice, the way, for instance, apple cider vinegar is vinegar made from apple cider. Plum vinegar, or umezu, "is really not a vinegar but often colloquially referred to as 'ume plum vinegar' even though it is made from the concentrated and pickled juices of the ume fruit," says ipsedixit. In flavor and consistency, it's not the same as vinegar. "Plum (or ume) vinegar is quite strong in its distinctive flavor and really is not a 1:1 substitute for rice vinegar, which is mild and neutral in comparison," says ipsedixit.
If umezu gets you on a plum kick, the Chinese make a drink called sour plum juice, says ipsedixit, from smoked ume fruit. "It's a great summertime drink. Sweet, sour, and lip-puckering good," says ipsedixit. "Sort of like the Taiwanese version of American lemonade." Tripeler thinks that this suan mei tang is delicious: "I have a bottle in the refrigerator and sometimes sneak a splash into cocktails. It's also great with hot water when I get a cold or sore throat. Amazing things can be done with it." For instance, try a dash in pot roast or in your meatball mixture, says ipsedixit. "You'll have your guests giving up their first-born for your 'secret' ingredient. Cheers!"
Discuss: Plum Vinegar?