John Crosby Eldredge was an alumnus of Iowa State College (University) (Agronomy, 1915) and a faculty member here from 1921 until his retirement in 1960. He was an agronomist whose specialization was research and development of popcorn hybrids. He is best known for developing hybrids identified with the term “Iopop;” Iopop 6 was grown on about 25,000 acres across many states in 1955, and at the time almost all white popcorn produced was either Iopop 5 or Iopop 7, also developed by Eldredge. (Ames Daily Tribune clipping, RS 9/9/51, Box 2, Folder 11). His research included studying the effect storage conditions have on popping volume and moisture content of popcorn. In 1954, he received the Distinguished Service Award of the Popcorn Processors Association and was an honorary member of the Iowa Crop Improvement Association.
In the March 1949 issue of Iowa Farm Science, Eldredge wrote about the research being done to develop improved popcorn. He stated, “We’ve worked to combine several good qualities – flavor, high popping volume, strong stalks for better picking, high yields and disease resistance.” (Box 1, Folder 18). Iopop 5 was released in 1946, and in 1949 was “rapidly becoming the most widely grown hybrid of the Japanese hulless type in Iowa. It is a white popcorn with excellent plant and popping quality.” He judged white popcorn to be more tender and yellow popcorn to be more flavorful.
Want to know the best popcorn to grow in Iowa? Well, with further developments in hybridization in the last 65 years, it has quite possibly changed since Eldredge’s recommendation in the same article mentioned above from 1949. However, at that time he recommended Japanese Hulless (a white variety) and Yellow Pearl (as the name suggests, a yellow variety). For home growers who are okay with a low yield, Tom Thumb (“an unusual variety”) was recommended for its “extreme tenderness and good flavor.”Once you grow your popcorn, how should it be stored? Here are some more 1949 recommendations: keep kernels at 14% moisture (best popping results occur at this level). This can be done by storing it outdoors in a corn crib or other shelter – according to Eldredge, a typical Iowa winter “will hold popcorn at about 14 percent moisture.” Artificial drying was also an option, but had to be done carefully. If dried too much, it won’t pop well, if dried too fast, the wet ears will come out too wet and the dry ears too dry. Once the popcorn is uniformly dry at 14%, storing it properly is also important. “For home storage the best method we know is to place the popcorn in airtight containers with cover on tight.” Just make sure to put the cover right back on – the corn can dry out too much within an hour or two if the lid is left off. Don’t worry too much, though! Too-dry popcorn can be moistened by setting it outside for awhile to “let the atmosphere correct the moisture content.” Another option is to put a tablespoon of water in a quart jar of popcorn and stir or shake well, then pour from one container to another to until the moisture is spread evenly – this will ensure more even popping.
Of course, today many of us just buy our popcorn in microwaveable bags, which is a pretty recent phenomenon – microwaveable popcorn bags weren’t invented until the early 1980s. Growing your own popcorn is still an option, though, and if you’re looking for more modern tips, here’s a starting point. For more information on John Crosby Eldredge and popcorn hybridization, come in and see the John Crosby Eldredge Papers, RS 9/9/51. As always, we’d love to see you!