With a lovely tartness and a beautiful effervescent sparkle, fermented berries are simple and quick to make. Serve them over custard, yogurt or ice cream, or tuck them into the blender for your morning smoothie. .
Put the berries in a pint-size jar. Pack them tightly with your clean hand or a wooden spoon. In a bowl, mix culture starter or whey, a few tablespoons of water, sugar, and salt. Pour the liquid ingredients over the berries, and then fill jar with filtered water, leaving 1 ½ inches of headspace. Press down with fist or wooden spoon to be sure the water has filled all the air pockets. Add more water if necessary.
Be sure the berries are below the waterline, using a weight if necessary. Put a lid on and leave at room temperature for 1-2 days. Store in refrigerator and use within 1-2 months.