We studied the use of vinegar in cooking in the Edo period, through the details of vinegar dishes extracted from 33 cookbooks of that period. A total of 1,371 varieties of vinegars were used throughout the Edo period, which was slightly more than the types of soy sauce used. However, cookbooks from the early Edo period mention vinegar 1.5 times more often than soy sauce. Therefore, we speculate that vinegar was the most commonly used seasoning before soy sauce became popular. The most frequently described vinegar dish in these cookbooks was "fish namasu", which accounted for 43.9% of all the vinegar dishes. There were 122 types of vinegar mixed with spices, foods, or seasonings, of which 61 types were vinegar-mixed miso, to which spices or foods were added. The Edo cookbooks mention several cooking methods with heat, using vinegar termed "suiri". This was primarily used for dishes prepared by simmering. Two types of simmering were described, viz., simmering after adding vinegar, and adding vinegar after simmering in suiri. Other cooking methods, such as heating with a small amount of vinegar, and pouring hot vinegar onto raw fish, were also described. Use of vinegar for cooking with heat, appears to be popular during the Edo period, which is not very common in modern Japanese cuisine.
Elliptical vibration of a whetstone was proposed and investigated in this study as a simple method for sharpening kitchen knives in homes. Sharpening tests were conducted using kitchen knives with worn edges. The method satisfies fundamental concepts for kitchen knife sharpening because the whetstone does not leave the cutting edge, and sharpening is performed in the direction from the spine (mine) to the cutting edge (hasaki) along the entire cutting edge of the knife. For comparison, a sharpening test using linear whetstone vibration was also conducted. After sharpening tests with both methods, kitchen knife cutting performance tests were conducted, and the effects of sharpness improvements were compared. Both vibration sharpening methods showed kitchen knife sharpness improvement, but elliptical vibration sharpening exhibited better improvement. Elliptical vibration sharpening tests were conducted using a completely dulled kitchen knife. The results demonstrated that kitchen knife sharpness improved equivalently to the sharpness of the new knife. These results demonstrate that this elliptical vibration method can effectively sharpen kitchen knives.
We conducted a lunch-time taste education program based on Jacques Puisais' approach for 3rd grade schoolchildren in an elementary school in Japan. We prepared worksheets in which the children described the food using each of the five senses. The children practised "Mandarat" in advance, so that they could easily think of appropriate words for describing the food. We also prepared taste cards to allow the children to express their feelings freely. The children recorded their impressions of the school lunch for 6 months without any suggestions. Initially, they described the food using only the word "delicious"; however, gradually they referred to the colours, shapes, textures, sounds, and smell or aroma of the foods. Food wastage from the school lunch gradually decreased as this program progressed, and almost no food wastage was reported after 6 months.