When I wrote coffee and chamomile in the title I realized it sounded like I was drinking some kind of gross hybrid beverage. Let it be known therefore, that I like my coffee and herbal teas quite well and quite separately. As you can see from the picture, chamomile here refers to the flowers I have growing on my balcony (german chamomile is better for tea than roman). I was delighted at my last count (23 little flowers), but the size of these guys means I will likely be able to brew maybe two cups of tea in the end. Internet searching suggests at least 2 tsp of dried flowers for a cup of tea, and these flowers are much tinier than I anticipated. Ok, the scientist in me just got out a ruler and measured 3/8 inch diameter for the fresh flower and about 1/4 inch for the dried. The fact that I have ANY flowers to harvest counts as a great success though, and I look forward to having two pots of these out next year. They grow in a very tidy vertical fashion, perfect for my limited outdoor space.
I am no expert, but I believe you have to wait to harvest until the white petals pull all the way back from the yellow buttons. And even then I waited some more because sometimes there was still green in the centers so I waited until it was yellow all over. The scent of chamomile becomes stronger as it dries, I couldn't really smell much when it was fresh (maybe it was allergies too though). The part to use for tea is the yellow buttons, but I don't plan on devoting my life to plucking away the white petals as I think they are rather pretty. Discard the green stems. I let the flowers dry on the countertop for a few days and then collect them into a glass jar. Will keep you posted on how much I use for tea when I have enough.