Interesting article. I had no idea. I use a stove topper espresso maker. I think it's the tastiest and most economical as far as getting the strongest cup with the least amount of grounds. It's a whole deal now with me. I add turmeric golden milk mix, tiny bit of black pepper and cinnamon, and some type of fat like coconut oil or avocado oil. It's almost impossible for me to get a satisfactory cup away from home now. Hah.