René Redzepi and David Zilber

In order to provide you with a good picture of both stages of vinegar fermentation, we’ll begin with a recipe in which we first make alcohol through the fermentation of natural sugars, then ferment that alcohol into acetic acid with the help of acetic acid bacteria (AAB).

Roasting brings a lot of rich, fully developed flavor to this garum, meaning it needs only about a month of fermentation to coax out more umami. If we were to ferment this chicken garum as long as we do beef or squid garum, it would lose its subtlety and complexity.

Lacto-fermented blueberries are one of the easiest and more versatile products in this chapter. They need no prep other than a quick rinse, and once they’re done you’ll find heaps of simple uses for them: Toss some onto your morning yogurt and granola, or add them to a smoothie, or puree the fruit and juices to make a salty-sweet coulis to be drizzled over ice cream or fresh cheese. Fermented blueberries freeze well and thaw quickly, making them easy to keep on hand at all times.