On the hillside of Caldwell Ridge Farm, the minimum temperature recorded by the minimum thermometer Ruth Ellen had driven into the soil between the rocks of the upper section was 33° F. The difference was exactly what the UT experiment station bulletin had predicted. The limestone had absorbed heat during the preceding warm days and released it through the night of the frost, raising the temperature of the hillside microclimate between 3 and 5° above the value at the county weather station in the bottomland. All 340 Tennessee Mountain Cayenne plants on the Caldwell Ridge hillside showed no frost damage. Ruth Ellen recorded it in her notebook with the date, the county station temperature, the hillside thermometer reading, and a visual observation of the plants the following morning. It was the first real field verification of the effect that the assessment had declared a risk and the UT bulletin had predicted as an advantage.
The first year I documented with a discipline that would have satisfied any university research committee that asked me for evidence. Every two weeks without exception, I measured the minimum nighttime temperature at three points on the hillside using minimum mercury thermometers I had bought at a pharmacy in Cookeville, and compared those readings with the county weather station temperature. I took soil samples at five fixed points on the hillside marked with red painted steel rebar so I could always find them and five points on the bottomland for reference. The samples went into labeled plastic bags with the date, point code, and depth. And every two months, I sent them to the soil testing lab at Tennessee Tech.
I measured the height and stem diameter of 20 plants marked with different colored yarn in each section of the hillside to keep a growth record by zone. Everything went into a notebook with columns for date, point, result, and observations. My cousin Paty had started going over it with me on Sunday mornings with the same attention she used to give the farm accounts, marking the weeks where the upper section data deviated from the average.
The researcher from the UT experiment station, Dr. James Whitfield, came to the farm for the first time in February of 1980, sent by a colleague who had mentioned the project at a research meeting in Knoxville. Dr. James was 41 years old with a doctorate in upland production systems from the University of Kentucky and the habits of researchers who work in difficult field conditions. He came in work clothes, got down to check the soil before speaking, asked questions before drawing conclusions.
He walked the hillside alone for two hours, took his own samples, measured with his own instruments. When he finished, he asked Ruth Ellen to show him the notebook.
He read it for 20 minutes in the shade of the cedar tree. Then he said, "Your differential temperature data is the most consistent I have seen from a limestone hillside in Middle Tennessee under real production conditions. Can I come out monthly this year?"
The second year was when the data started saying what no opinion could any longer discredit. In March of 1981, Dr. James came with Dr. Sandra Morse, a researcher from the University of Tennessee Food Science Department, who had spent 12 years documenting traditional capsicum varieties in Tennessee, Kentucky, and the western Carolinas, and who had heard about the Cookeville project from Dr. James at the annual UT agricultural research conference in Knoxville.
Dr. Sandra came with her own equipment, paper bags for fruit samples, a macro lens camera for documenting plant and fruit morphology, and a field notebook with a recording system that Ruth Ellen recognized immediately because it was similar to the one she had developed herself. Dr. Sandra walked the hillside alone for two hours, choosing her own sampling points. She took fruit samples from each section.
She did not talk much during the process. When she finished, she sat with Ruth Ellen in the shade of the cedar tree and talked for 30 minutes.
The cayenne from the upper section of the hillside, the plants growing directly on the limestone with the least soil depth, had a capsaicin concentration measured on the Scoville scale that was 38% higher than Tennessee Mountain Cayenne grown on the bottomland fields. The thin soil and the moderate moisture stress that the assessment had described as unfavorable conditions were producing exactly the effect that generations of Putnam County Hill Country growers had observed without measuring. Stressed cayenne runs hotter, and hotter cayenne sells at a higher price in the specialty spice market. Dr. Sandra asked Ruth Ellen whether she would be interested in co-authoring a paper on traditional capsicum varieties in the Tennessee Uplands.
Ruth Ellen answered, "Let me finish the third year and have the commercial yield data. I'd rather publish when the evidence cycle is complete."
There is something I want to explain here before going further because it has to do with something that most Middle Tennessee pepper growers in the 1970s did not know and that Harold Briggs's assessment had documented as a problem without understanding that it was exactly the opposite. Cayenne pepper, unlike most commercial crops, produces its primary active compound, capsaicin, as a stress response. A cayenne plant grown in deep soil with adequate moisture and available fertilizer produces abundant biomass, large fruit, and lower capsaicin. A cayenne plant grown in thin soil with limited moisture from fast drainage between rocks and without available fertilizer produces smaller fruit but a significantly higher capsaicin concentration. In the specialty dried pepper market of Middle Tennessee, price is not set by fruit size or weight.
It is set by heat intensity. The Nashville buyers paying a premium for Tennessee hill-country cayenne were paying for capsaicin. Even if they said it in different words, they said flavor. They said heat. They said character.
The science behind it was the same. Thin soil plus moderate moisture stress plus a native variety selected for those conditions over generations equals high capsaicin. The limestone hillside of Caldwell Ridge Farm with its 8 inches of soil over bedrock and its rapid drainage between rocks was exactly the system that produced that result. The assessment had described that system as unsuitable for agriculture. It was the most suitable system available for producing exactly the cayenne that the premium market paid the most for.
The third year was the year Harold Briggs stopped coming to the hillside with his clipboard and started coming without it with his hands in his jacket pockets looking from the foot of the hill with the changing expression of a man who is quietly reconsidering whether he was wrong. That year, Ruth Ellen made the first complete commercial harvest from the hillside. The Tennessee Mountain Cayenne from the upper section, the plants growing over the densest rock with the thinnest soil, came in that October of 1981 with a smaller pod than the bottomland average, but with a deeper red color and a dry fragrance that Sandra Morse had described in her notes as the characteristic aromatic marker of the Tennessee mountain variety, distinguishable from flat ground cayenne at a distance of 6 ft. Ruth Ellen brought a sample to the regional produce market in Cookeville, another to a specialty spice distributor in Cookeville she knew from her time at the Antioch plant, and a third directly to a Nashville buyer that James Whitfield had put her in contact with. All three made the same motion when they opened the sample bag.