Identify dried-shrimp sizes and distinguish them from fermented shrimp paste

The short answer

Dried shrimp and fermented shrimp paste are two separate ingredients. Dried shrimp, called goong hang in Thai, are whole small shrimp preserved by salting and sun-drying. They come in roughly three sizes: papery-thin, medium and very large. Fermented shrimp paste, called gapi in Thai, is a salty paste made from fermented small shrimp or sometimes krill. It is not a ground-up form of dried shrimp, and a recipe that calls for one cannot simply swap in the other.

For most cooking, medium dried shrimp are the most versatile choice. The cook behind the Hot Thai Kitchen ingredient guides recommends medium dried shrimp as an all-purpose pantry staple.

How to recognize the dried shrimp sizes

Dried shrimp are sold as individual dried pieces with a concentrated, savory flavor. The Hot Thai Kitchen guidance describes three sizes by how they look and eat. These sizes are relative descriptions, not standardized numerical grades. Judge a package by what you can see through it, not by a size word on the label.

Size	What you see	How it behaves in cooking
Papery-thin	Very thin, almost translucent pieces, often with the tiny eyes still visible	Delicate and light. The Hot Thai Kitchen cook rejects this type as a crisp topping for shrimp paste fried rice.
Medium	Distinct, firm individual shrimp of moderate size	The versatile option. It is the cook's choice for frying until crisp as a rice topping.
Very large	Big, thick dried shrimp	Can be chewy, according to the same source. Less suited to dishes where the shrimp should turn crisp.

How to tell dried shrimp from fermented shrimp paste

The form gives it away. Dried shrimp are separate whole pieces. Gapi is a smooth, dense paste with a purplish-gray color and a salty, pungent character. Because gapi is a paste, the size distinctions above do not apply to it.

• Thai shrimp paste (gapi): usually sold packed in tubs.
• Malaysian belacan: a fermented shrimp paste sold as wrapped bricks.
• Orange 'shrimp paste in soybean oil': despite the label, this jarred product is not fermented gapi. It is cooked shrimp tomalley (the rich, fatty part from the shrimp head) with herbs and seasonings, and it plays a different role in cooking.

Watch for that last label in particular. A shopper looking for gapi can easily pick up the orange jar because both say 'shrimp paste.' Check the color and form: purplish-gray paste in a tub or brick is the fermented product, while orange paste in oil is the tomalley product.

Why the difference matters in a dish

Kao kluk gapi, a Thai shrimp paste fried rice, uses both ingredients for different jobs. In the Hot Thai Kitchen version, fermented shrimp paste seasons the rice itself. Medium dried shrimp are an optional topping, fried until crisp. The recipe lists them separately because one provides seasoning and the other provides texture.

Choosing the right product for your recipe

Pick the product in two steps. First, match the form the recipe asks for: whole dried shrimp or fermented paste. Second, if the recipe calls for dried shrimp, choose the size it prefers. If no size is specified, medium is the safe default.

Illustrative example: a simple shopping worksheet for kao kluk gapi might look like this, with columns for product, visible form, relative size and the recipe's requirement.

Product                      | Form                    | Size           | Recipe role
Medium dried shrimp          | individual dried pieces | medium         | optional crisp topping
Papery dried shrimp w/ eyes  | thin pieces             | papery         | not the cook's choice for the topping
Gapi                         | paste                   | not applicable | seasons the rice

Where to find them

In the US, look in Asian grocery stores. The Hot Thai Kitchen guide points shoppers to the refrigerated section for dried shrimp. For shrimp paste, look for Thai gapi in tubs. If you are cooking Malaysian dishes, look for belacan in wrapped bricks. Before buying any jar labeled shrimp paste, check its color and contents so you do not confuse the orange tomalley-in-oil product with fermented paste.