Harvest ripe raspberries until you have enough for the task at hand.
Pick over your harvest, removing leaves, twigs or bugs.
Place part of the clean raspberries in a quart jar, filling 3/4 full.
Add chlorine-free water until the berries are just covered.
Cover with a lid to keep dust and fruit flies out.
Leave the jar to rest at the back of your counter for 3-4 days.
Strain out berries, keeping the red liquid.
Fill the jar with berries once again.
Pour the infused berry liquid over and let it sit for another 3-4 days.
Strain. You can repeat the infusion process 1 more time or start fermenting the liquid.
When you're ready to ferment, pour the liquid into a quart glass jar.
Cover with a cloth, paper towel or coffee filter.
Fasten your cover into place so that fruit flies cannot get in.
Wait for several weeks, then check for bubbles on the side of your jar as a confirmation that the yeasts are working.
If pink froth appears on the surface of your juice, skim it off.
Let the juice continue to ferment until it begins smelling like vinegar (approx 6-8 weeks in total).
When you think the vinegar is ready, test by sealing some up in a bottle or jar.
Let sit for 2-3 days at room temperature before breaking the seal.
If there is a release of CO2, let it ferment for another 2-3 weeks. Retest until there is no release when you break the seal.
Bottle the vinegar in a food grade container and store for up to 2 years.