First, the eggs are boiled slowly for about 60 minutes in a hot spring pool at around 80 degrees. The iron in the hot spring water adheres to the eggshell, making it black. When you try it, you can taste a slightly sulfuric aroma and a different deliciousness from regular boiled eggs.
First, the eggs are boiled slowly for about 60 minutes in a hot spring pool at around 80 degrees. The iron in the hot spring water adheres to the eggshell, making it black. When you try it, you can taste a slightly sulfuric aroma and a different deliciousness from regular boiled eggs.