Add a few drops of sour to your favorite DIY e-liquid recipe to give your vape a pleasing sour sensation. Sour is best when used in combination with fruit, citrus, and gummy flavors. We recommend starting at 1%, then flavoring to taste.
"Sour" is one of the seven basic taste sensations. The other six are sweet, bitter, salty, umami (savory), pungent/piquant, and metallic.