Frozen yogurt is a great choice for a snack if you follow the gluten-free diet most flavors and many toppings are naturally gluten-free, and frozen yogurt chains are pretty gluten-aware.
However, as with any dining out situation when you've got celiac disease or gluten sensitivity, you can't throw caution to the wind. Yes, there are still a few opportunities for that mostly gluten-free yogurt to gluten you.
Toppings likely will be your biggest concern, since many of them do contain gluten (think: cookie crumbs and unsafe candy most chains have a list). Most fro-yo shops I've visited have all the toppings grouped closely together, so even if you're choosing, say, the fresh fruit, you still could wind up with a stray cookie crumb in your yogurt.
Also, even if the fruit seems well-segregated from the cookies, you need to watch out for the spoons the person before you might have loaded up his yogurt cup with Cookies & Cream and then accidentally touched the topping spoon to that gluten-y flavor, or he might have borrowed the spoon in the strawberries temporarily to dish out some Oreos. If you prefer to stay completely safe, you might want to consider bringing your own toppings (that's actually what I do).
Beware of the machines themselves, as well. A yogurt shop owner told me that it's almost guaranteed to get gluten cross-contamination in a machine that had been used for a gluten-containing flavor and then switched over to a gluten-free flavor it's difficult to clean these machines as thoroughly as we would need. When I'm buying frozen yogurt, I stick with gluten-free flavors I know the store stocks regularly, because they're always in the same machines. Tart is usually a safe bet (most stores carry it all the time), but if I'm in doubt, I'll ask the workers.
In some cases, flavors that sound like they have gluten (Cake Batter? Cheesecake?) are listed as gluten-free by one frozen yogurt chain, but not by another always double-check before you buy, especially if you're not a regular at that particular shop.
Finally, as you serve yourself from the machines, watch out for drips of potentially unsafe yogurts if your preferred flavor shares a yogurt machine with a gluten-containing flavor, one unnoticed drip from the other side or the swirl spout in the middle can ruin your day.
Okay, enough safety information. Here's an alphabetical list of popular frozen yogurt chains, plus their gluten policies and gluten-free lists, where available:
Cold Stone Creamery. The national ice cream chain Cold Stone Creamery announced the debut of its frozen yogurt line in every store in summer 2011. According to the company's ingredients statement, none of the frozen yogurt flavors available contain gluten. You'll need to double-check toppings for gluten ingredients the stores keep a list of ingredients for all the toppings available.
Menchie's. Menchie's Frozen Yogurt, a chain with locations in nearly every state, states: "With the exception of flavors that contain "cookies" or "cake," our yogurt flavors are gluten-free; however, they are produced in a facility that also manufactures products containing gluten as well as peanuts, treenuts and egg products." You can access the list of flavors here.
Orange Leaf Frozen Yogurt. This chain boasts more than 150 locations (with lots of stores in the Southeast and Midwest) and intends to expand to 250 stores quickly. Orange Leaf Frozen Yogurt discloses gluten-containing flavors on its website and in its stores. Surprisingly, according to the list, the only flavor that contains gluten is Cookies 'N Cream even flavors such as Wedding Cake, Cheesecake and Brownie Batter are listed as gluten-free.
Pinkberry. Pinkberry has close to 200 locations and is expanding rapidly both in the U.S. and nationally the company, which started in southern California in 2005, bills itself as "the original frozen yogurt." According to the chain, "All Pinkberry frozen yogurt flavors are gluten-free." Of course, many possible toppings are not gluten-free, so be careful.
Red Mango Frozen Yogurt. All Red Mango yogurt flavors are certified gluten-free by the Gluten-Free Certification Organization, which means they contain fewer than 10 parts per million of gluten. The chain has locations in more than 30 states and a strong presence in the New York City metro area.
Sweet Frog Frozen Yogurt. Sweet Frog, a yogurt chain with locations concentrated in the Southeastern U.S., does feature a handful of gluten-containing yogurt flavors, so you'll need to take care in choosing your yogurt. According to one franchise, the flavors Red Velvet Cake, Cake Batter, Whoppers, Angel Food Cake, Thin Mint Cookies and Cookies n' Cream all contain gluten, and others on the flavors list ("Maple Bacon Donut"?) look suspicious. However, I can tell you that my daughter and I frequent two Sweet Frog franchises, and we've been okay sticking to flavors like Tart and Vanilla.
TCBY. The Country's Best Yogurt, which opened the first frozen yogurt shop in the U.S. in 1981, now offers more than 450 stores nationwide. TCBY does not have a gluten-free list because the U.S. Food and Drug Administration has not released final gluten-free standards, according to a customer service representative. However, the customer service rep said that the only two yogurt flavors that contain gluten are Cookies & Cream and Gingerbread; the rest of the chain's flavors are gluten-free to 20 parts per million (ppm). Despite the gluten-y-sounding names, Cake Batter, Cheesecake and Red Velvet Cake are considered gluten-free, again to 20ppm.
Yogurt Mountain. Yogurt Mountain, a smaller chain with 40 locations in 15 states so far, offers only two flavors that contain gluten: Cookies & Cream and Caramel Pretzel. Potential customers can search on the website to identify gluten-free, fat-free, low-fat, no sugar added and dairy-free yogurt options.