Collard greens are flavorful, hearty, and delicious, but they have an inherently bitter flavor. If you find their bitterness too strong, there are ways to counteract it.
Start by buying the right kind of collard greens. They like cold weather, and their taste can even be improved by frosty or snowy conditions, while heat can make them more bitter.
The chemicals that give collard greens that bitter taste are called glucosinolates. If you blanch the greens, some will be released into the water, minimizing bitterness.
You can also braise collard greens for a velvety-smooth finish. The bitterness will be diluted into the liquid to create an ultra-flavorful broth called the potlikker (pot liquor).
You can also balance out bitter collard greens with the right seasonings. Saltiness, sweetness, spiciness, and acidity can all help to add some balance.
Lastly, if you aren't planning on cooking the greens for very long, cut them into thin ribbons to help tenderize the leaves and make their texture and flavor less assertive.