Black garlic has a really lovely deep umami flavour that reminds me of liquorice and balsamic vinegar. It’s quite sweet and savoury at the same time, with some hint of garlic in the background.
Essentially, it’s just fresh garlic heads left at a particularly low temperature – between 60-90C with a specific humidity for, I think, a couple of weeks. The heads dry out and cook, and turn from the wonderful creamy colour that we know to totally black and shrivelled.
At Ottolenghi, we use Sweet & Savoury black garlic. I use it a lot with fat. I do a black-garlic butter: crush the black garlic with the side of a knife or a pestle and mortar, then whip or mix it with soft butter. If I roast a chicken – even a turkey – I often put this black-garlic butter underneath the skin. It gives the chicken a nice flavour, and the cooking liquids – the base for a gravy – have a particular black garlic depth.
I use it for vegetarian and vegan cooking as well. I would use it in a vegan bolognese based on lentils and barley, and it’s really good for a risotto. I also like to mix it with other garlic. In the last book, Flavour, we’ve got a recipe for three garlic butter. By three garlic, I mean black garlic, confit garlic and raw garlic. Together it gives you all these iterations of garlic. To make a quick yoghurt sauce, you crush your black garlic cloves and add it to yoghurt with fresh garlic. It makes the most beautiful barbecue style sauce that’s great on roasted vegetables.