Fish maw, also known as the swim bladder of a fish, is an internal organ filled with gas that helps fish control their buoyancy in water. It is considered a delicacy in Asian cuisine, particularly in Chinese cooking. When cooked, fish maw has a slightly oily taste with a pleasing chewy yet firm texture.

Fish maw is normally sold in a dried form, so it requires preparation before use. The dried fish maw needs to be soaked in water to rehydrate, which may take several hours or even overnight. After soaking, the fish maw is boiled to further soften it and remove any fishy odors. One thing to note is that it expands significantly when rehydrated, so a small piece will go a long way.

It is rich in collagen and often used in soups, stews, and braised dishes, and is believed to have multiple health benefits such as improving skin complexion and revitalizing one's energy. Despite its bland flavor, it absorbs the taste of other ingredients it's cooked with, making it a versatile addition to various dishes. It can be a bit pricey due to its high nutritional value and the intricate process of preparation.

Fish maw is a type of dried seafood product often used in Chinese dishes. In a grocery store, you may find it in various sections:

1. Asian or International Section: Many supermarkets have aisles dedicated to international cuisines. Fish maw, being a common ingredient in Chinese cuisine, might be found in the Asian food section.

2. Seafood Section: Some grocery stores keep fish maw near other seafood products.

3. Dried Goods Section: Since fish maw is often sold in its dried form, it might be stored in the dried goods section among other dried items like mushrooms or seaweed.

Remember, not all grocery stores will stock fish maw as it is considered a specialty item. If you can't find it in your local grocery store, try Asian supermarkets, particularly those specializing in Chinese products.

Finally, multiple online retailers sell fish maw, including Amazon, ebay and many others specializing in Asian foods.