The secret material to remove berry, wine, and other tough stains is
vinegar. Use straight white distilled vinegar; it is readily available
in all supermarkets. While organic apple cider vinegar is the perfect
vinegar for ingesting, it has a color and can stain fabric. Soak
stains in straight white distilled vinegar. First rinse the stain well

then rest the part of the fabric that is stained in a bowl of straight
vinegar. Rinse. Launder as usual.