3 minutes. Shredded kelp needs to be blanched for about 3 minutes. Kelp is an ingredient with high nutritional value, often eaten on the body is very beneficial. Shredded kelp does not need to blanch for too long, in general, shredded kelp after washing, the pot into the hot water, boil over high heat, add shredded kelp, blanch for 2-3 minutes can be fished out, so that the nutritive value of shredded kelp can be retained for the most part.