Does parsley make soup bitter?

My guess is that broccoli was the culprit. I always use a few fat stems of parsley wth carrots, celery, onion etc. for making stock.

I find parsley a little bitter. I like that at times, but I don't use it in veg broth. When I use it in soups, it's usually as a garnish stirred in at the end for its nice grassy notes.

The fresh parsley grown in my garden is amazingly sweet. Use it all the time. If the parsley is old and turning yellow, it can be bitter. And stems may not work. What else was in your broth?

Parsley is mildly bitter and adding the leaves for soups, whole parsley sprigs with the stems for broth in my opinion balances out the rest of the ingredients. How much did you use and what other ingredients did you include? Too much parsley and not enough other flavors to could increase the bitterness if not balanced.