Most curries use very similar ingredients.
Thai curries are differentiated by their colors, which emphasize the key ingredients that give each curry its distinctive flavor. At their core, most curries are relatively similar. They all rely on chili peppers, coconut milk and similar spices to achieve their flavor. But minor differences produce two wildly different dishes.
Chilies
The variety of chilies used affects both the color and the flavor of curry. Green curry is the only curry made from fresh, green chilies. This produces a fresh, crisp, bright-tasting curry with a very distinctive color. Yellow curry, like red curry, uses a base of dried, red chili peppers. Yellow and red curries tend to be more mellow but with a deeper flavor than green curries due to the dried peppers.
Spices
Green and yellow curries' varying spices account for their differences in flavor and color. Green curry relies on coriander and cumin to provide its distinctive flavor. Turmeric gives yellow curry its bright yellow shade and mellow flavor. Turmeric is a root in the ginger family, and is usually available dried in the spice section of most grocery stores. Some cooks prefer to use curry powder instead, because it's packed with turmeric along with coriander, cumin and several other spices.
Aromatics
Yellow and green curry have the most in common when it comes to aromatics. Shallots, garlic, ginger and lemongrass make flavorful additions to most varieties of curry. Both curries rely on the sea to deepen their flavor, either with fish sauce or shrimp paste. Green curries are infused with citrus flavor from lime juice, zest and leaves.
Heat
Green curries have a reputation for being the spiciest of all of the varieties. The fresh, green chili peppers used in the dish are hotter than the dried, red chilies used in yellow curry. Yellow curries tend to be sweeter and less spicy than green ones, although the spiciness of the dish varies from cook to cook.
Tags: chili peppers, chilies used, coriander cumin, curries tend, distinctive flavor