I'm going to add another essay under this post to advocate for nail-polish processed coffee.

For decades, the gold decaf standard used to be the swiss water process. Caffeine is one of the most water soluble parts of the coffee bean. It works by (1) rinsing green coffee beans in hot water to make something of a coffea tea, (2) filtering the caffeine out of that tea, and then (3) using that cooled tea to rinse the caffeine out of a new batch of coffee.

But chemical solvents work much better, and today, ethyl acetate is one of the best. I drink decaf coffee processed using ethyl acetate. It's a chemical solvent, but it makes for a noticeable difference.

It helps that the US has more lax standards for what constitutes decaf. A cup of coffee that would be 100mg can instead have something like 5mg, while the EU demands something vanishingly close to zero. Getting those last 5mg means a more aggressive processing.