Combine raspberries and vinegar in a sterilized glass jar with an
airtight seal. Leave in a warm place to steep, shaking jar
occasionally.
After 2 weeks, strain vinegar from raspberries using a fine strainer.
Press raspberries gently to extract flavor.
Add vinegar and sugar to a saucepan. Over low heat, simmer for
10 minutes. Transfer to sterilized jars or bottles. If desired, place
a few ripe berries in the bottle.
