The Unexpected Dried Ingredient To Help Thicken Sauces

Yawning at the thought of using cornstarch slurry, butter, eggs, or heavy cream to thicken your sauces? If you're looking for a secret ingredient to serve as a liaison and to enhance the flavor of your sauces, look no further than kombu, a dried kelp widely used in Asian cuisine, especially to make Japanese dashi. 

A beautiful seaweed, long known across Asia for its natural umami properties, kombu emerges today in the culinary world as a low-calorie thickening agent that gives sauces rich, full-bodied consistencies. Kombu is a versatile alternative to traditional thickeners, working its transformative magic through a gelling class of polysaccharides known as alginates.

When first trying kombu, start by rehydrating a sheet of it in water and introducing it into your sauce or soup at the start of cooking. As it simmers, kombu will infuse the liquid with its alginates, naturally thickening the mixture. The resulting sauce will be luscious and velvety with a hint of umami; however, to truly harness kombu's powers as a thickener, try processing it into a fine powder.

To start, begin by dehydrating kombu sheets in an air fryer, oven, or dehydrator until the sheets are crisp. Once crisp, grind the sheets into a fine powder using a spice grinder or mortar and pestle. Store this versatile powder in an airtight container, and use it as a seasoning or a thickening agent in savory dishes and sauces. 

Famously flavorless thickening agents like cornstarch don't provide the added depth of umami flavor that kombu powder offers. Its subtle briny and glutamic taste beautifully complements the earthiness of a mushroom pasta sauce or a cream or tomato-based seafood dish, for instance. It can also deepen the flavors and thicken consistencies in a classic French bouillabaisse or an Italian cioppino.

Regardless of your dish or sauce, adding kombu introduces a unique and transformative umami-rich thickness, establishing it as a fun and magical ingredient in any kitchen.