Close but no,
USN Chief’s mess coffee ground MaxwellHouse brewed w 2 pinches of salt
I have heard of adding salt but didn’t know why. I guess it reduces the bitterness. I’ll have to try it. It seems the guy below adds more than a couple of pinches:
“In 2009, food science expert Alton Brown suggested adding salt to coffee in an episode of his cooking show Good Eats. He said that for every cup of water and two teaspoons of ground coffee, you should add half a teaspoon of salt to neutralise the bitterness of the coffee.
“Not only does salt cut the bitterness, it also smooths out the ‘stale’ taste of tank-stored water. Research has proven that salt is actually better at neutralizing bitterness than sugar,” he said.
Although Brown wasn’t the first to put salt in coffee, he drew widespread attention to the technique. Today, even in 2024, some even coffee drinkers know it as “the Alton Brown Trick”.”
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I have also heard of people adding eggshells to the coffee grounds before brewing. I just looked that up - same reason, to reduce bitterness. Eggshells are mostly Calcium Carbonate I guess.