In your mixer, whisk egg yolks (leaving whites in yet another bowl), add beer, butter and salt.
Remove and beat egg whites until stiff. Fold into beer batter mixture. Dip onions into flour, then mixture and fry evenly on each side until golden brown.
Drain on paper towels and serve.
Video
[adthrive-in-post-video-player video-id="IYJF90jx" upload-date="2018-09-01T00:00:00.000Z" name="How to make Homemade Crispy Onion Rings" description="A video tutorial of how to make Homemade Crispy Onion Rings with just a couple of ingredients. It makes the appetizer, snack or side dish!"]
Notes
Use your favorite beer, such as a light lager or ale.