What are the slimy bubbles in soaked kombu?
I have made dashi a couple of times now, starting soaking kombu in water. And always I found these little bubbles on the leaves, containing white slime:
I have never worried about them much and simply cut them away when eating the kombu later, but what are those bubbles? My hypotheses are: 1. just random bags of alginate slime, or 2. natural growth due to parasites or other incorporated matter.
Best Answer
According to the "Handbook of Kelp Farming", Sporangia are usually close to the centre of the blade, so it is highly unlikely to be that.
As seen here: https://www.ispotnature.org/communities/uk-and-ireland/view/observation/807675/rain-blister-39disease39
This appears to be what is called "Blister Disease", thought it is not really a disease but rather it "is caused by a sudden decrease in salinity due to mixing of rainwater with seawater. The disease often appears after heavy rainfalls and generally occurs in shallow bays which are vulnerable to salinity changes caused by freshwater run-off."
Source from FAO: https://www.fao.org/3/AB724E/AB724E09.htm
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Quick Answer about "What are the slimy bubbles in soaked kombu?"
Brown algae are rich in alginate and soluble fiber and these elements get slimy when they are wet. These two nutrients are especially rich in Kombu seaweed and is said that wet Kombu was used to transport heavy rock by sliding on top by using this trait.Why is my kombu slimy?
When Kombu sheets are in contact with water, the mannitol forms the slime. Since Kombu's umami flavor largely relies on the presence of mannitol deposit, gentle rinse instead of excessive washing is recommended (and which is why it is important to buy good quality clean Kombu sheets to eliminate the need to wash them).What is the white stuff on kombu?
These white spots are called "mannitto" or "umami seibun" in the Japanese language and are part of the Dashi Kombu. These white spots occur as part of the natural drying process of the product and bring out the flavor; it is recommended not to wash Dashi Kombu before use in cooking.Why do you not boil kombu?
Please be careful not to boil too much as if Kombu seaweed is boiled until large bubbles starts to appear, Kombu seaweed's stickiness will drain and will affect the flavor. Add bonito flakes. Turn off the heat when water is boiled.Is dashi supposed to be slimy?
We like the clear taste. The Dashi should not be slimy, so we always take out before boiling. Transfer to a glass jar, and you can keep it for the three to four days but best using fresh.How to Make Kombu Dashi (Recipe) 昆布だしの作り方 (レシピ)
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