There are many kinds of rice noodles used in Asian cooking. Like Italian pasta, the shape and size of Asian rice noodles determine how they're used. For pho noodle soup and other pho noodle dishes, you want banh pho -- flat rice noodles. The round bun rice vermicelli noodles are used for other dishes, including rice noodle bowls and rice paper salad rolls (goi cuon, sometimes called fresh spring rolls). and super fine banh hoi are employed to eat with grilled or roasted meats.
Flat rice noodles are sold in different widths to match cooking applications; they are used in Vietnamese, Thai, and Chinese cuisines and thus marketed for popular dishes like Vietnamese pho, pad Thai, and Cantonese chow fun. Like clothing sizes, there is no standard for the sizing rice noodles, but for your purposes, organize them into two categories:
- Narrow rice noodles (linguine or fettuccine size) are perfect for pho noodle soup.
- Wide rice noodles (think pappardelle) work best for the stir-fried, panfried, and deep-fried noodles.
Pho noodles are available fresh and dried. In Vietnam, fresh noodles are relatively easy to obtain, but people use dried ones, too. Abroad, the situation is reversed: most cooks prepare dried noodles and occasionally get fresh ones. Don’t worry, because the dried ones have a terrific chewiness that’s practically as good as fresh.
Below is the photo we made for The Pho Cookbook. You'll see in the book that the image is labeled, but without labeling and detailed explanations, it can be challenging to figure out how to find and buy pho rice noodles. What's with the dried vs. fresh noodles and the seemingly odd sizing?
There is a difference in how dried and fresh noodles are used in recipes and you should follow what the recipe suggestions. With regards to The Pho Cookbook, check the instructions in each recipe and also in the “Pho Manual” chapter.
Here’s a summary of your noodle options: