3 stalks of lemongrass
2 cups rice vinegar
Slice the bottom 8 inches of the lemongrass stalks thinly, then put the slices in a very clean 1-qt wide-mouthed glass jar. Bruise the slices with a wooden spoon. Add the vinegar and let the mixture steep, covered with the lid, in a cool dark place for at least 4 days and up to 2 weeks, depending on the strength desired.
Strain the vinegar through a fine sieve into a glass pitcher, discarding the lemongrass slices. Pour it into 2 very clean 1/2 pint glass jars, and cover tightly with lids.