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Chester County Press

The Quiet Man

09/01/2023 03:01PM ● By Lori Harrison ,VP Communications for American Mushroom

Chester County has a rich history, but there’s probably one story that you haven’t heard that happened here, in Chester County, about a breakthrough discovery, a world war, and of course, mushrooms. 

Let’s begin in the early 1900’s with a young man named Raymond Rettew. Born in West Chester, Pennsylvania, he attended the University of Delaware and Swarthmore College, graduating with a degree in chemistry. In March 1926, after working in his father’s law office, Rettew accepted a position as a chemist at the Charles E. Hires Company in Philadelphia, Pennsylvania. 

While Rettew’s primary work was in microbiological control, the company allowed him enough time to take an advanced bacteriological course at the University of Pennsylvania, and the professor allowed Rettew to use the laboratory during late hours and on weekends to conduct studies and help Rettew start his own business. 

In his own words from his memoir, “A Quiet Man from West Chester,” Rettew talked about this time in his life. “My father-in-law, Mr. Wilmer J. Divine, was employed in the cultivated mushroom industry. In my talk with him, it became evident that the business needed scientific study and scientific help. During my off-hours I did research in the production of mushroom spawn and in pH studies of casing soil and compost. My brother-in-law, Floyd W. Divine, who was also in the mushroom growing field, tested the results in the mushroom houses.”

In the meantime, another factor was developing in Rettew’s life. While commuting to the Hires Company, he rode on the train from West Chester every day with Joseph W. Strode. On their commutes, they would talk about a variety of things, including Rettew’s interest in the challenges faced by the mushroom industry. One morning, Strode made Rettew an offer: “When you are ready to go into the mushroom spawn business, let me know.” As Rettew explained in his memoir, “That very evening, I went to see him and for many years to come, we were partners.”

In 1929, the two started production at the Chester County Mushroom Laboratories, in West Chester, Pennsylvania. Strode supplied the money and Rettew supplied the know-how. The idea was to supply mushroom growers with the highest quality spawn produced by scientific methods and conduct original research for applying spawn. In three years, the lab was the largest spawn maker in the United States. 

In 1931, a subsidiary corporation was established, The Premier Mushroom Company. Rettew visited Clarence Birdseye—yes, that Birdseye—concerning freezing mushrooms. Birdseye was pioneering freezing vegetables, so Premiere entered into a contract with Birdseye, and after some successful tests with freezing mushrooms, Premiere became one of the first companies to package and sell frozen foods. 

The War Effort

In the decade that followed, Rettew’s company enjoyed many successes; spawn sales increased here in the United States and overseas, he was awarded a few patents for use in his research, and more. Things were going very well. 

But World War II changed Rettew’s approach to business. He encouraged the industry to study the food value of mushrooms so they could be declared an essential food. Rettew also tapped into his hobby studying chemical substances produced by fungi to see if he could be of any help in the war effort. He was a self-described ‘tinkerer’ and had been working on the extraction of the enzyme tyrosinase from mushrooms. The extraction was successful, but the medical use was questionable. 

A few years before, Alexander Fleming observed the growth pattern of mold on a staphylococcus culture plate. Specifically, he saw that if penicillium, a genus of fungi, was grown in the appropriate substrate, it would produce an antibiotic substance, which he called penicillin. Fleming later deduced that penicillin could be used as an antibiotic to treat life-threatening illnesses including meningitis, pneumonia, syphilis and other forms of bacteria.

It wouldn’t be until more than 10 years later that it was discovered penicillin was in fact, a ‘miracle cure.’ On May 14, 1942, the first American patient was treated with penicillin. The patient was a woman named Anne Miller. The diagnosis was septicemia, also known as blood poisoning, that had left her near death from an infection that followed a miscarriage. She had had a fever of at least 103°F for multiple weeks. She received roughly a tablespoon of penicillin, and within about a day, her temperature was back to normal.

The Discovery

Back in Chester County, Rettew was researching ways to help. He was familiar with the work of  Dr. Harold Raistrick of the University of London, who pioneered research on the chemical composition of fungi. He had also studied penicillin, and in 1941, Rettew read papers and articles that indicated penicillin had great promise for healing infected wounds. He was also aware of the news that the men fighting in WW II were dying at high rates from infections and amputations. 

So Rettew went to work.

Having studied penicillin intermittently since 1928, Rettew knew that by altering the culture, or medium in which the mycelium grew, he could improve the quality of the spawn. He figured the same process would apply to penicillin growth. "This," he wrote in his memoirs, "would be our way of contributing to the War effort."

The original work was done in Rettew’s private laboratory above the garage of his home. There, he proved that the experience of extracting chemical substances from fungi, together with the techniques used for the culture of mushroom spawn, made a good starting point for the study of penicillin. 

Rettew had found a way to commercially produce penicillin. This was a significant discovery, as previous attempts by researchers to make penicillin widely available was “difficult and expensive to extract” from its original mold source. Before Rettew, it had not been available in synthetic forms; every time scientists wanted to make penicillin, they had to wait for new mold to grow. So, he put his idea into action. 

Through his friend Dr. E.B. Lambert, he contacted the Chairman of the Committee on Medical Research of the Office of Scientific Research and Development located in the National Academy Building in Washington, D.C. The building is of note because it’s the same building where the control center was housed for the atomic bomb. It was there that Rettew convinced the leaders that the Chester County Mushroom Laboratories could contribute to the penicillin program, which the Federal Government had just established as a priority.

Funded by the federal government and John Wyeth and Brother Incorporated, a subsidiary of the American Home Products Corporation, Rettew went to work with penicillin samples provided by the Department of Agriculture's Northern Regional Research Laboratory at Peoria, Illinois. Using his own lab's UV lights and temperature control mechanisms to meticulously sterilize the medium bottles, Rettew was soon able to produce five-gallon drums of penicillin–but there was a problem. "Since penicillin was not particularly stable," Rettew later wrote, "degradation was often faster than separation of the liquids." The solution, it turned out, was to use a centrifuge manufactured by the Sharpless Cream Separator Company of West Chester to separate the penicillin from the growth medium. "Penicillin production today would not be possible without this method," Rettew later noted. He then constructed a penicillin recovery building equipped with a large refrigerator, Sharpless centrifuge, and a 100-gallon tank.

By June 1943, Rettew's Chester County Mushroom Laboratories were the nation's most consistent source of commercially available penicillin, more than ninety percent of which went directly to the armed forces. By the fall of 1943, an expanded lab in West Chester, PA, utilizing Rettew's surface culture technique, was producing most of the world's penicillin. 

The Next Chapter

History books point to Alexander Fleming for discovering penicillin, and he and his colleagues were awarded the Nobel Prize in Physiology or Medicine for their discovery in 1945. Rightfully so. 

But there is more to the story. Rettew was a self-described quiet man, happier with his research and experiments than standing in the spotlight. You’re hard-pressed to find mention of Rettew in the history of penicillin; a quick Google search offers only the slightest nod buried deep in a Wikipedia page: “The private sector and the United States Department of Agriculture located and produced new strains and developed mass production techniques.” Those ‘mass production techniques’ helped to save countless lives on the battlefield and even more throughout the years that followed. The ‘Quiet Man from West Chester’ may have shied away from the spotlight, but his discovery changed the world. 

Decades later, his family is trying to not only keep his story alive and increase awareness of Rettew’s impact through a documentary titled, The Mushroom Man Who Changed the World: G. Raymond Rettew. Recently premiered at the Chester County History Center, the documentary tells the story of a man who took his work producing spawn for the mushroom industry and turned it into a groundbreaking discovery. 

American Mushroom, headquartered in Avondale, is a national voluntary trade association representing the growers, processors, and marketers of cultivated mushrooms across the United States and industry suppliers worldwide. For more information, visit