Growing, Sampling and Testing 2005 The heat level of a chilli is determined by both by its genetic make-up and the conditions under which the plants are grown. Dorset Naga undoubtedly has the right genes, but we feel our growing conditions may have also contributed to the high heat levels measured in the 2005 crop. Growing conditions Since Dorset Naga needs a long growing season, its seed are sown in mid January at a commercial nursery. Plants are then delivered to Peppers by Post by mid April, and transplanted into raised beds in unheated polytunnels. Harvesting at the green stage usually begins at the end of July/beginning of August. The chillies are not over-fertilised. Garden compost or cattle manure is rotavated into the tunnels’ heavy loam soil every year to improve its tilth. Nutrients are supplied by a single application of pelleted chicken manure made at the beginning of the growing season. Watering, kept to a minimum, is through drip irrigation tubes laid on top of the beds. The only serious pest are aphids, which are controlled by predator release. Occasionally, the populations get out of hand, and we resort to spraying a commercially-available liquid formulation of corn starch. Collecting and preparing the Dorset Naga sampleFruit for testing heat levels were picked in early September. Though the crop was grown in two tunnels, fruit was picked only from the hotter of the two. About a hundred fully ripe fruit were harvested – no selection criteria were followed other than avoiding the very smallest. The fruit were laid out on baking trays and dried in a domestic gas oven. They were regularly turned and rotated in an attempt to dry them evenly. Once dried, the stems and calyces were removed and the whole fruit ground in an electric coffee mill. The mill had previously been used for grinding spices, but had been thoroughly washed before being used for chillies. The resultant powder was transferred into a plastic bag, then triple bagged so that no powder could escape. Conducting the heat level test The reminder of the sample was then sent to Certified Laboratories in New York for a second heat test. At the same time they were asked to test for any adulteration that could have artificially raised the heat level of the sample. Their analysis came in at 970,000 SHU, and the adulteration test (done on solvent residues) showed nothing out of the ordinary. The laboratory is ASTA accredited and works to ISO 17025. Both laboratories tested the heat level by High Pressure Liquid Chromatography (HPLC). See certificate from Southwest Bio-Labs |
