Our condiments don't explode is a pretty good sales slogan

I always assumed concerns over preservative were a post-war thing. Lots of other things feel modern about this too, like the way companies use research findings to build brand and attack their competitors.

From Sam Lin-Sommer:

Fermentation also sped up a more dangerous process: Occasionally, bottles of fermenting ketchup would explode. In 1895, the New York Sun reported, “A bottle of catsup exploded on the dinner table of a family at Michigan City, Indiana, recently, and the force knocked all of the dishes off the table.” A 1903 headline in the Saint Paul Globe read, “BOTTLE OF CATSUP EXPLODES IN HER HANDS: Twelve Year Old Emma Setley Is Badly Cut By Flying Glass.”

To protect customers and their bottom lines, ketchup companies embraced chemical preservatives. Smith cites turn-of-the-century studies in California, Connecticut, and Kentucky that found that the majority of commercial ketchup samples contained some form of antiseptic.

Then, in 1883, a man named Dr. Harvey Wiley became chief of the Division of Chemistry of the United States Department of Agriculture, where he fought preservatives with the religious zeal of a man raised evangelical in rural Indiana. Born in 1844 in a log farmhouse, he spent his childhood tending to his family’s crops, then earned chemistry and medical degrees before shifting the Division of Chemistry’s focus to the food-safety problems that plagued the nation.

For the next two decades, he proposed countless Congressional bills on food safety, each of which was killed. But in 1904 he formed “The Poison Squad,” enlisting a group of healthy, young, male volunteers—mostly his colleagues at the Department of Agriculture—to eat all of their meals at work and ingest increasingly large quantities of preservatives. The results read like the last 10 seconds of a modern-day drug commercial: stomach cramps, headaches, sore throat, dizziness, decline in appetite, and loss of weight. Multiple trials stopped when participants became too sick to continue. Sensationalized in the press, “The Poison Squad” shifted public opinion against preservatives.

At a meeting of the U.S. regional canners associations in 1907, Wiley called for a ban on the use of benzoates, the preservative of choice for the ketchup industry. But executives were not convinced; Wiley couldn’t come up with an alternative to prevent ketchup bottles from souring and, occasionally, exploding.

But then Wiley gained a powerful ally: Henry Heinz, owner of the H.J. Heinz Company. Once a teenage horseradish peddler, by the age of 52 Heinz helmed a condiment firm with offices in London, Antwerp, Sydney, and Bermuda. But it wasn’t until the early 1900s, when he removed preservatives from his ketchup line, that he became the largest tomato-ketchup producer in the world, Smith writes in Pure Ketchup.

Heinz supported Wiley’s food-regulations movement, according to Heinz’s biographer Robert C. Alberts, because of “idealism and noble purpose compounded with self-interest.” Heinz stood at the forefront of food hygiene, so regulations would only help the company command high prices and maintain its reputation.

...

Thanks in part to high-quality ingredients, Heinz’s new tomato ketchup cost two to three times more than its competitors. But the price increase also paid for the largest advertising campaign the industry had ever seen. In one of several advertisements to grocers, “Heinz stated that grocers should ‘get rid of any chemically preserved foods’ before they were confiscated by the government,” Smith writes. Heinz took out a two-page spread in the Saturday Evening Post that shouted, in block letters: “WARNING! THE U.S. Gov’t Says benzoate of Soda in Foods Produces Injury to Digestion and Health.”

In response to Heinz and Wiley, a cabal of ketchup companies formed a fierce pro-benzoate lobby. In meetings with President Theodore Roosevelt, they argued that an anti-benzoate law would destroy the ketchup industry. American grocery stores stocked few preservative-free, shelf-stable ketchups, so the lobby said that Heinz’s claims were impossible, and they spread rumors about ketchup bottles exploding without preservatives. According to Smith, an industry journal reported that “a priest in Washington, Pennsylvania, ‘was hauled across the room and struck his head against the door’ because of an explosion caused by the lack of preservatives.”

...

In 1908, a board of scientists created by President Roosevelt ruled that benzoate of soda was harmless if consumed in quantities of less than a half of a gram per day. But this didn’t matter: Wiley and Heinz continued their campaign on public opinion, and Americans soured on preservatives. By 1915, Smith writes, most major ketchup companies stopped using them altogether, and those that didn’t lost many of their customers. It helped, too, that the thick consistency of Heinz’s preservative-free ketchup allowed it to cling tenaciously to the hot dogs, hamburgers, and french fries that swept the nation in the 1900s.