The Food Lab: Better Home Cooking Through Science

As with dried spices, the flavor of the chiles can be
enhanced by toasting them dry (see “Whole Versus Ground
Spices,” here). This accomplishes two goals: First, the heat
catalyzes reactions among individual compounds within the
chili, creating new flavors. Second, the Maillard browning
reaction takes place, resulting in hundreds of highly
flavorful new compounds.
After toasting, I could go the traditional route and simply
combine the chiles and grind them into a powder, but I’m
not one to bow to tradition. Instead, I found that by cooking
them down in chicken stock and pureeing the moist chiles, I
could create a completely grit-free paste for a concentrated
flavor base for my chili. The best part? If I made a double or
triple batch, I could freeze the puree in ice cube trays for
long-term storage, giving me the convenience of jarred chili
powder but vastly better texture and flavor.