Itsumo yatte iru yo!
Wiki has it wrong. I make dashi from kelp and fish flakes all the time. It's really easy.
I start by tossing a piece of kelp in my pot, and adding water.
I bring it to a boil on low.
I think this is what makes dashi less cumbersome.
They're self-closing tea bags. Great for making tea, but also great for making dashi. And you can stuff herbs in there instead of fish flakes when you're making chicken stock.
While the kelp-water is heating, I stuff about a handful of fish flakes in the bag.
When the water comes to a boil, I turn the heat up and toss in the bag in the water and hold it down until the bag and flakes are soaked throughly, let the water boil for another minute or so, then turn off the heat and let it sit for two or three minutes.
I take out the bag and let the bag cool on a plate for a few minutes.
Then I squeeze out any excess water still in the bag.
Now, this is the SAHM Pumpkin Mommy method.
The Professional Career Pumpkin Mommy tosses a piece of kelp in a pot of cold water and lets it sit at room temp until she comes home, and brings it to a boil on high.
She has a stash of already-stuffed fish flake tea bags in a ziplock bag in her pantry that she tosses in when the water comes to a boil.
The rest is the same.
The points are that bringing out the flavor of kelp into the water takes time, so a slow heating process (or just soaking in water for a very long time) is what you need, but for bringing out the flavor of fish flakes, you need a short, brisk period of heat.
Too long, and you will end up with an overly bitter broth from amino acid overdose. Apparently, the taste buds, when confronted with an umami overload, get confused and send an erroneous signal of "bitter" to the brain.
There, it wouldn't have been a Pumpkin Mommy cooking post if there hadn't been a taste of geekiness thrown in for good measure, would it?