Every answer on this site starts from the question you actually ask in the aisle: is this one safe or not? Below is the running index, grouped so you can find a food fast. Where the answer is it depends, the linked article explains exactly what it depends on.
Grains, flours and starches
This is where most of the real risk sits. Wheat, barley and rye are the three gluten grains, and several foods that sound harmless are made from one of them.
- Buckwheat — yes, despite the name
- Millet — yes
- Grits — yes, it is ground corn
- Polenta — yes, it is cornmeal
- Corn syrup — yes
- Oat milk — yes, if certified
- Quaker Oats — only the certified line
- Couscous — no, it is semolina wheat
- Orzo — no, it is wheat pasta
- Farro — no, all three types are wheat
- Bulgur — no, it is cracked wheat
- Barley — no, it is a gluten grain
- Rye bread — no
- Matzah — no, it is flour and water
Drinks and alcohol
Distilled spirits are usually fine, because distillation leaves the gluten proteins behind. Beer is the opposite: if it is brewed from barley it contains gluten, no matter how light it tastes.
- Coca-Cola — yes, it is safe
- Root beer — yes, despite the name
- Sweet tea — yes
- Sake — yes, it is fermented rice
- Rum — yes, it comes from sugarcane
- Tito’s — yes, corn based
- Deep Eddy — yes, corn based
- Bourbon — yes, distillation removes it
- Gin — yes, distilled
- Vodka — yes, distilled
- Smirnoff — yes, distilled
- Jameson — yes, distilled
- Boba — the pearls are, toppings vary
- Ginger ale — nearly always
- Corona — no, barley beer
- Modelo — no, barley beer
- Coors Light — no, barley beer
- Stella Artois — no, barley pilsner
- Guinness — no, barley stout
Sauces, condiments and dressings
Condiments are the most common hidden source of gluten, usually through soy sauce, malt vinegar, or a wheat-flour thickener nobody thinks to check.
- Cholula — yes
- Frank’s RedHot — yes
- Rao’s sauce — yes
- Ketchup — nearly always
- Salsa — fresh salsa almost always
- A1 Steak Sauce — check the label
- Barbecue sauce — brand by brand
- Thousand Island — by brand
- Taco seasoning — check the brand
- Yum Yum sauce — usually, by brand
- Worcestershire — depends on brand
- Soy sauce — usually not, use tamari
- Eel sauce — usually not, soy based
How to read a label quickly
Four words do most of the work: wheat, barley, rye and malt. Malt is the one people miss, because it is barley in disguise and it turns up in vinegar, drinks and breakfast cereal. After that, look at thickeners and anti-caking agents, which is where wheat flour hides in seasonings and sauces.
Two more distinctions are worth knowing. Naturally gluten-free and certified gluten-free are not the same claim, and oats are the clearest example: the grain is fine, the mill usually is not. And grain-free is not a synonym for gluten-free, because the two labels answer different questions.