Shio Koji Tomato Butter
In the summer I like to buy flats of tomatoes from local farms and then spend the next few days in the kitchen transforming them. Holding a sturdy cardboard box of these heirloom jewels makes me feel rich. If you can, use dry farmed tomatoes for this recipe. Dry farming is when watering and irrigation is discontinued once the plants become established. The result? A brilliant water saving measure AND the most flavorful tomatoes you will ever have the pleasure of putting into your mouth. Dry farming is easier done in places that have rainfall patterns like California: a rainy winter and a precipitation free summer. So if you aren’t able to easily acquire these gems, don’t fret. The best tomatoes are still the ones that grow closest to you.
Shio koji is a salty, umami packed paste made from salt, water and, of course, koji. Koji is a brilliant Japanese ingredient that is made when a grain, usually rice, has been inoculated with the fungus Aspergillus oryzae and left to ferment for a few days. The fungus slowly digests both the proteins and the starches in the grain which results in a both a higher level of sugar and a higher level of free amino acids. The star amino acid is glutamic acid, which imparts savoriness to foods. Have you ever wondered what MSG, the darling of the packaged food world, stands for? Monosodium glutamate. Basically it is an isolated and refined form of what we are tasting when we eat Parmesan cheese, sun-dried tomatoes and miso.
This is one recipe that is a bit labor intensive but a little goes a long way and I promise that you will thank yourself when you are able to doctor up your soups, pastas and beans with a spoonful of this tangy, umamilicious concentrate.
INGREDIENTS
3 lbs (1350g) dry farmed tomatoes, sliced into wedges
¼ c shio koji
2 Tbsp olive oil
DIRECTIONS
Heat the oven to 300°F (150°C).
Mix all ingredients together and let stand for about 5 minutes to allow the tomato juices to be drawn out. Strain the juices into a small saucepan.
Place the wedges on a parchment paper lined baking sheet, skin side down. Discard any seeds that have become loose as they will make the butter bitter. Roast until the tomatoes begin to brown at the tips, about 60-90 minutes.
While the tomatoes are roasting reduce the tomato liquid. Heat saucepan over medium heat and simmer the liquid until it has reduced to about ½ c. It should be thick like mayonnaise. Set aside.
Once the tomatoes have cooled a bit add them to a food processor along with the tomato reduction. Puree until smooth. For the silkiest texture pass mixture through a fine mesh sieve or cheesecloth.
Yield: ~2 c
NOTES
A variation that will result in an even smoother texture and an increase in the sweetness of the final product would be to de-skin and de-seed the tomatoes. To do this, bring a pot of water to boil. Take a sharp knife and make an X on the bottom of each tomato. Plunge into the boiling water for about a minute, until you see the skin of the tomato begin to curl. Remove and set aside to cook. Peel the skin off and then cut tomatoes in half. Remove seeds and roughly chop. The roasting time will be reduced to 45-60 minutes.