There are different methods to produce dashi, from simply infusing kombu in cold water to extracting it like an essence by immersing it in water, heating it, and then removing it just before boiling.
● The flavor of dashi isn't just influenced by the way the kombu is immersed in water.
Wouldn't you expect that the water used also affects the resulting flavors?
Taste sensors that model the human tongue have been widely around the world used since the early 2000s by research institutions, analysis centers, and food-related enterprises.
Here, we've evaluated the effects of different types of water on the flavor of cold water-infused dashi using one of these taste sensors.
● The chart displays quantified values for the flavor of dashi using six specialized taste sensors.
Although the readings from the "umami" sensor are roughly the same, the readings for "texture" and "depth" are far higher for dashi made with alkaline ionized water than pure water.
Regarding the effect of water's "hardness" on dashi: while hard water brings out more of the dashi's richness, Kono reports that the hard water's harsh flavor is undesirable.
Alkaline ionized water also has a higher mineral concentration than pure water, but it does not reach high enough levels of hardness to cause any harshness. It's thought that its superior extraction capabilities allow it to draw out more of the kombu's depth, resulting in layers of richness and a broad, complete flavor profile.
c 2016 アルカリイオン整水器協議会.