Onsen tamago
Onsen tamago ( Japanese 温泉 卵 or 温泉玉 子 ) or onsen eggs are eggs that have been cooked in Japan's hot springs called onsen .
preparation
Unlike the usual boiled eggs, they usually cook for around an hour at temperatures between 62 ° C and 69 ° C, which means that both egg white and yolk only coagulate slightly and have an evenly waxy consistency, comparable to lost eggs . At 70 ° C the egg white would stagnate, which is not wanted. Since the coagulation temperature of egg yolks is 65 ° C, there are marked differences in the choice of temperature above and below this temperature for the cooked onsen egg. It is just a matter of preference whether you boil onsen eggs below or above this temperature point. Due to the minerals dissolved in the water, the eggs also take on a more or less salty-sulphurous taste, depending on the source. In spas like Beppu , these eggs are sold at street stalls.
Black eggs
In the Ōwakudani Valley ( 大 涌 谷 ) near Hakone there are special onsen tamago, so-called black eggs ( 黒 玉 子 , kuro-tamago ), in which dissolved sulfates and iron ions in the spring turn the shells black. They are hard-boiled due to the heat of the springs.
Western cuisine
With the spread of the low-temperature method in western gourmet cuisine, the method of preparation of the onsen ice cream was also adopted and refined. Christian Lohse serves peeled onsen eggs breaded in panko and deep-fried , giving the very soft eggs a thin, crispy shell.
