Rinse the dried soybeans under running water to remove any dirt or debris. Spread them out on a clean kitchen towel and pat dry thoroughly. Removing excess moisture prevents splattering when roasting.

Pour the dried beans in a single layer onto a rimmed baking sheet. Roast at 400°F for 15-20 minutes, gently stirring halfway through. The soybeans are ready when lightly browned and fragrant. Be careful not to burn them.

Alternatively, you can roast in a dry skillet on the stovetop over medium-low heat for 10-15 minutes instead, stirring frequently.

The toasted soybeans need to cool down fully before grinding to prevent the released oils from becoming gummy. Spread out on a baking sheet or plate to cool quickly.

Working in small batches, grind the roasted beans into a fine powder using a blender, food processor, spice grinder, or coffee grinder. Avoid overloading it.

For electric models, pulse in short bursts to prevent overheating. Process each batch for 2-3 minutes until very finely ground.

Sift the soybean powder through a fine mesh strainer or sieve to remove any large gritty bits. Discard any remnants that won't pass through. The final product should have a super fine, smooth consistency.

Transfer the fresh soybean powder into an airtight container. Store in a cool, dark place like the pantry for up to 3 months. For maximum shelf life, store in the refrigerator.