This recipe is a nice entry point into the experimentation-friendly world of DIY cocktail bitters. Grapefruit might just be my favorite point on the citrus triangle: in this humble pink sphere, we find orange’s sweetness, lemon’s brightness, and a unique floral citrusyness all dancing in harmony. Cocktail bitters are a perfect medium to distill all this flavor into a concentrated tincture, and it gets even more fun when you start curating spices to support and accentuate the grapefruit. Effort-wise, all you have to do is throw a bunch of things in vodka for a couple weeks, and you’re set. I store my grapefruit bitters in a pint mason jar and add a barspoon to white negronis, pretty much any mezcal-based cocktails, or even just seltzer on ice. (Homemade bitters also make nice, batchable gifts, especially if you transfer them into 4oz dropper bottles.)
A few notes. First, grapefruit has a relatively thick layer of bitter pith compared to most citrus. This is annoying when you’re trying to eat pieces of grapefruit flesh, but we’re making bitters here! The pith is a feature, not a bug, so don’t bother cutting it away from your swaths of zest. Second, the spice selection is highly customizable to your tastes and what you have on hand. I would say coriander and cinnamon are key – coriander has a nice lemony earthyness, and cinnamon adds sweet-spicy complexity – but beyond that, go wild (just err on the side of using very little of each spice, as some of them dominate quickly). For example, I didn’t use cloves, but I think adding one clove could be nice. Third, I’ve listed gentian (the primary bittering agent in Campari and many other liqueurs) as optional; if you don’t have it, add some extra pith to compensate.