There’s a long-standing practice some people swear improves their coffee: putting salt in it. They claim it will cut the bitterness of coffee and it also smooths out the ‘stale’ taste of tank-stored water.

The premise is that salt, even more than sweetness, tempers bitterness.

I tried it myself and can’t say I noticed much difference in the flavour or bitterness of my coffee, either black or, as I usually take it, with a splash of cream.

Is the salting-your-coffee trick overblown?

Even if a person could notice salt’s mitigating effects on coffee bitterness, is that desirable? It’s difficult to pin down an exact definition of bitterness as it relates to coffee; some people might describe a dark roasty flavour as bitter, while others might mistake acidity for bitterness. 

Spencer Turer, a quality expert at Coffee Enterprises, a coffee consulting and analysis firm, is sceptical of any attempts to mess too much with a properly brewed cup. 

“If you’re buying good coffee and you have a good roaster, you’re not going to get the bitterness you need the salt for,” he tells me. “It goes back to the days when the quality of coffee wasn’t that good; maybe [a roaster] is using robusta in the blend and it’s not all arabica and you’re looking to cut the bitterness.”

He notes that caffeine is itself a bitter compound, an alkaloid, which means that coffee beans will always naturally contain that.

“If you’re buying good coffee from a specialty, quality coffee roaster, and if you’re using the right equipment, coffee can be delicious—savory and sweet and all that without anything—without salt, sweetness, additives, or creamer.”