what do you mean by “washed coffee grounds”?

Question

I take the used coffee grounds out and dump into my planters…I have not also washed or rinsed them. Why would anyone do that? I think I am missing something in the discussion.

Answer 1

In the article below, they are comparing the use of unwashed (fresh) coffee grounds with used (brewed) coffee grounds as a way to lower the pH of soil. Fresh coffee grounds are acidic, whereas once the grounds are brewed, they become neutral. I believe the author is using the words "rinsed" or "washed" to denote brewed coffee.

https://www.gardeningknowhow.com/composting/ingredients/coffee-grounds-gardening.htm