Lactic acid is a clean organic acid with a gentle yet punchy sourness that occurs naturally in fermented foods. In the Alchemy kitchen we use it in tiny amounts to brighten savoury plant cheeses and rich cheese sauces, where it creates a subtle, cheesy tang. I use lactic acid sparingly and with intention, reserving it for a select few dishes where it is particularly useful. It can help plant mozzarella, cashew cream cheese, nacho cheese and pesto taste more cheesy and umami.