The citric acid in your food is grown on a black mold. Pfizer figured out how to mass produce it and it's how Pfizer learned to make penicillin. Nearly all of it, about 2 million tons a year, comes from a fungus called Aspergillus niger fed sugar in steel tanks. The mold eats the sugar and gives off citric acid. The acid gets filtered off, crystallized and sold as a white powder. A Pfizer chemist named James Currie got it running at scale in 1919, and by 1939 a pound had gone from $1.25 to 20 cents. The deep tanks Pfizer built for citric acid are the ones it used for penicillin in 1941, when it was the only company making it by fermentation. About 60% of it is made in China, and the US has had tariffs on Chinese citric acid since 2009 at the request of ADM, Cargill and Tate & Lyle. Sprite, Gatorade, Hunt's tomatoes, Kraft mac and cheese, Pillsbury frosting and the liquid eggs on a hotel line all have it. It's the most used acid in food because it's cheap, it's sour, it keeps cut fruit from browning, and it holds pH where bacteria don't grow. A 2018 paper described 4 people who reported joint pain and swelling after eating foods with manufactured citric acid, but the authors wrote that nothing had been proven. No large scale controlled study has been run since.

Great Value frozen shrimp has 3 ingredients. Shrimp, salt and sodium tripolyphosphate. Sodium tripolyphosphate is a phosphate salt. The shrimp get soaked in a tank of it before they're frozen, and the phosphate loosens the muscle proteins, so they hold on to water. The shrimp come out of the tank heavier than they went in, and the bag is sold by weight, so part of what you pay for is tank water. It also keeps them from drying out in the freezer. Soaked shrimp sit in a puddle, steam instead of sear, and feel slick and a little rubbery. Untreated shrimp brown in the pan. Costco's Kirkland raw shrimp says no chemicals added and no preservatives on the bag. The FDA allows the phosphate, so the check is the ingredient list on the back of the bag, under the net weight.

The made-from-scratch crust on a Marie Callender's pot pie has no butter in it. It's soybean oil, and the gold color is caramel color. The front of the box says golden, flaky, made-from-scratch crust. The back lists the crust as enriched wheat flour, interesterified soybean oil, water, salt, modified whey and caramel color. There's no butter, lard or egg anywhere on the box. The chicken is white meat chicken, water and soy protein. The filling has methylcellulose in it. Interesterified oil is what replaced partially hydrogenated shortening after trans fat was banned. The plant heats liquid soybean oil with a fully hardened fat and a catalyst, and the fatty acids swap places between the two until the blend is solid at room temperature. It works like shortening in a crust and the label gets to say 0 g trans fat. The caramel color is there because a crust with no butter and no egg wash comes out of the oven pale. Methylcellulose is plant cellulose, usually from wood pulp, treated so it dissolves in water. It does the opposite of most thickeners. It's thin when cold and sets into a gel when it gets hot, so the filling stays put in the oven instead of boiling out through the crust, then loosens back up as the pie cools on the plate. Same ingredient that holds an Impossible Burger together.

Most decaf coffee is made with methylene chloride. It's the solvent that used to be in paint stripper. The green beans are steamed, then washed in methylene chloride, which pulls out the caffeine and not much else. The beans are steamed again to drive off the solvent and then roasted at over 400F. FDA allows up to 10 parts per million. When a lab tested 24 decaf brands in 2020 it found the solvent in 10 of them at about 0.05 to 0.1 ppm, around 100 times below the limit. The industry calls this the European method. There are 3 other ways to do it. Ethyl acetate, a solvent that can be made from sugarcane, which the trade calls the natural method. Carbon dioxide under pressure. And the Swiss Water process, which uses hot water and carbon filters and no solvent at all. Peet's says all of its decaf is water process. Starbucks has told reporters most of its decaf is the direct contact method, meaning solvent. EPA banned most uses of methylene chloride in 2024, but food is FDA's job, so decaf wasn't part of it. A petition to pull it from food has sat at FDA since December 2023. FDA reopened comments on it in May and hasn't decided. If the bag says Swiss Water or water process, no solvent touched it. If the bag says nothing, you don't know.

The ingredient called hickory smoke flavor is wood smoke condensed into a liquid, minus the tar. The EU is phasing it out. It's liquid smoke, and on a label it reads hickory smoke flavor or natural smoke flavor. Oscar Mayer bacon bits list it second, right after the bacon, and the front of the bag says hickory smoke flavor added because USDA makes you print that next to the name when the smoke goes in as an ingredient instead of from a smokehouse. Sweet Baby Ray's has it down in the under 2% group as natural smoke flavor. In November 2023 the EU's food safety agency finished going through the 8 smoke flavorings sold in Europe and couldn't rule out DNA damage for any of them. Two of the compounds it found, furan-2(5H)-one and catechol, are genotoxic in animal tests, and the agency said it couldn't name a safe level. In April 2024 the member states voted not to renew them. They come out of sauces and chips by July 2026 and out of ham, fish and cheese by July 2029. In the US it's a natural flavor and nothing has changed.