Guinness’ Fish Bladders and 4 Other Animal Secrets in Your Food

For those who treat a thick, creamy pint of Guinness as a meal, it will come as no surprise to learn that the famed Irish stout contains more than just hops.

For the past two centuries years, an obscure bit of fish product has been hiding in Guinness. Isinglass is a gelatin derived of fish bladders, usually taken from the sturgeon, that is used to filter and clarify the ale.  It ensures the yeast separates from the liquid. This week, the company behind the storied brew announced it has finally hit upon a new vegan-friendly filtration system and will begin rolling out the fish-less beer late next year.

But you might be surprised to learn Guinness isn’t the only common food item that relies on an animal by-product. There are crushed bugs in your Yoplait, calf stomach enzymes in your cheese, and bone in your cane sugar—to name a few of the unexpected additions to your grocery list. Read on to learn more.

How Marshmallows Get Their Bounce

Most vegetarians know to avoid the fluffy marshmallows stuffed tantalizingly between two graham crackers, since they contain a derivative of animal bones, tissues and organs called gelatin. And other sticky or gummy foods, like Jell-O and gummy bears include gelatin as well. But some gelatin-filled products are more sneaky: Planters Dry Roasted peanuts contain gelatin, so does Kraft American Cheese, and even Kellogg’s Frosted Mini-Wheats and Pop-Tarts.

Parmesan and Friends

Vegetarians will want to send the parmesan-grating waiter walking. By law, cheese can only be called ParmigianoReggiano or parmesan if it abides by certain production criteria outlined by the protected status it was granted in Europe nearly 20 years ago. This process includes using animal rennet—enzymes sourced from the stomachs of newly born calves—to turn milk into the thick substance we slice, sprinkle and spread.

While vegetarian-labeled cheeses use animal-free rennet made from bacteria or microorganisms, many common cheese varieties are typically made with regular rennet. Along with parmesan, gruyere, gorgonzola, camembert, and a slew of others traditionally contain the animal by-product. And strict vegetarians should also beware pesto: it often contains rennet-filled Pecorino Romano and Grana Padano.

Blood Red Bugs

Any food that’s fiery red likely gets its color from crushed insects. Carmine, cochineal extract and natural Red 4 are ubiquitous on the bottom of ingredient lists. But these ingredients, often grouped as natural coloring, come from the tiny cochineal bug, which has been used to make red dye for centuries. To get just one pound of pigment, around 70,000 insects are crushed, according to a 1997 study in the journal Allergy.

Many foods, including Tropicana grapefruit juice, Werther’s caramel cinnamon candies, Betty Crocker Red Velvet Cake comprise the list of unexpectedly bug-colored edibles. Yoplait yogurt also makes use of Carmine, arguing on its website that it’s “a safe, naturally derived, red coloring that is FDA-approved for use in food products.”

The Sweet Secret of Sugar

Even the most basic kitchen staple may have a secret animal ingredient. Bone char from cattle is often used during the filtration process when cane sugar is refined and whitened. The animal bones are heated up for hours until turning to carbon, which becomes a natural filtration device. The char removes color from the sugar, giving it that crystallin quality. Major refineries like Domino Sugar use the process, meaning most of their products are not vegan-approved. In this case, to avoid it, just buy organic: bone char doesn’t make the cut for the substances allowed in organic products, so any U.S. Department of Agriculture-certified organic sugar doesn’t use animal by-products.

Nina Strochlic is a writer for National Geographic. Hailing from Oregon, she was formerly a reporter for the Daily Beast, covering international human rights and women’s issues. Her stories have taken her from pygmy villages in the Congolese jungle to Syrian refugee camps in Jordan. Once, in Cuba, a man who claimed to be Fidel Castro’s chef cooked her a fish dinner. Follow her on Twitter.