Printed September 2, 2026
Fermented Cashew Koji Butter with Black Garlic
This umami-packed spread combines the enzymatic magic of koji with the sweet-funky depth of black garlic, creating a cultured butter that's equal parts mysterious and addictive. Slather it on everything or use it to finish roasted vegetables for an instant flavor upgrade.
Ingredients
- 200g raw cashews, soaked overnight
- 50g koji rice (rice inoculated with Aspergillus oryzae)
- 400ml filtered water
- 1 teaspoon sea salt
- 6 cloves black garlic, minced
- 2 tablespoons neutral oil
- 1 teaspoon white miso paste
- 1/2 teaspoon nutritional yeast
Preparation
This cultured cashew butter sits at the crossroads of Japanese fermentation tradition and modern plant-based alchemy. The koji breaks down the cashews into something silky and deeply savory, while black garlic adds its signature sweet-funky baseline that makes everything taste more alive.
The magic here is patience. Koji is a living culture that needs warmth and time to work its enzymatic wizardry, transforming simple nuts into something that tastes like it's been aging in a cave for months.
Preparation
- Drain the soaked cashews and blend them with the filtered water until completely smooth, about 3-4 minutes on high speed.
- Pour the cashew cream into a clean glass jar and stir in the koji rice, breaking up any clumps with your fingers as you mix.
- Cover the jar with cheesecloth secured with a rubber band (you want airflow, not an airtight seal).
- Keep the jar in a warm spot (around 80-85°F/27-29°C) for 48-72 hours. An oven with just the light on works perfectly. You'll notice it developing a tangy, sweet aroma.
- After fermentation, blend the mixture again with the sea salt, minced black garlic, oil, miso paste, and nutritional yeast until completely smooth.
- Transfer to a container and refrigerate for at least 4 hours to firm up. The butter will keep for 2 weeks refrigerated.
Serving Suggestions
Spread on sourdough toast, melt over grilled mushrooms, stir into hot pasta, or use as a finishing touch on roasted root vegetables. The funky umami depth works particularly well with anything charred or caramelized.
