Add Seaweed to the Paste
Adding salt until the water in the paste is “salty like the sea” is common practice, but nobody talks about the other salty, oceanic flavors that a large body of water has to offer. I wouldn’t cook pasta in real sea water, but you can add some minerality and mushroom umami to it with seaweed.
You can do this with any seaweed you like, but I prefer the kombu (most often used to make dashi ), which is absolutely riddled with white powdery crystals of the glutamic acid salt (also known as “half glutamic acid”). By the standards, you can play pretty fast and loose here. I added two 1 “by 4” pieces to two quarts of salt water for cooking, brought the water to a boil, and then removed the kombu just before adding the pasta, but you could probably add an extra sheet if you were that inclined. The ocean water has given spice spaghetti (which were intended for the cacio e pepe) piquant salty note. They were fantastic with butter and cheese, but I think they would really shine with garlic or scallop (yes).
Would it be weird with red sauce? Probably not, although tasting the seaweed will not be easy. Too much glutamate in pasta water is never a bad thing, but a sour tomato-based sauce can hide the softer mushroom flavor of kombu. But if starchy pasta water is the main ingredient in your sauce , the seaweed- added pasta water will make your sauce and noodles a lot more flavorful.