I recently discovered and hope it is true, that eggshells reduce acid in coffee. I know I have heard that some people put eggshells in their coffee, to improve the taste? But, I have started saving my eggshells, washing them out, and crushing about a half into the little cup that holds the grounds. I have one of those one cup makers but it has the option of using my own coffee without filling a pod. I find the eggshell dissolves completely and gives me some calcium too. I think if it affects the taste, I am not aware of it. I recently gave up the powdered creamer and use the little tubs of real half and half. I am enjoying my new recipe!