Do I need to grind Ceylon Cinnamon sticks for coffee/tea, or can I add them whole?
Most people just use ready-ground cinnamon.
It's much cheaper &amp; just stirs in with no chewy, twiggy bits.
Of course, it looks a whole lot better with en entire stick of cinnamon bark sticking out of a tall, elegant glass/mug, but the amount of flavour you're going to get from it is going to be minimal in comparison.
If you're cooking with cinnamon, it will simmer for several hours, after which you pick out the bits &amp; throw them away. You could see how much flavour you get from one steeped in hot water for 15 minutes or so &amp; it might be enough, but I'd save the sticks for a long-cook, or for when you need the look, rather than when you just need a hint of cinnamon in a tea or coffee.
I have never actually tried it myself [I keep both in the cupboard, ground &amp; sticks], but I doubt you'll get a smooth-enough powder from any home-grinder if you try to DIY.