Onion rings are just one use for this light and crunchy beer batter. It’s also great for fish filets, mushrooms, etc.
The secret is keeping the fizz in the beer, the air in the whipped egg whites, and using cake flour instead of all-purpose flour.
One caution… this batter is not forgiving of delay. When I cooked at a restaurant in the 1970’s I made it as part of my “prep” around 4pm. We served dinner from around 5-10pm. Towards the end of the shift you could tell the unique airy quality of the batter was diminishing.
The rings themselves are at peak quality for only a short time. They should be served hot, as soon as possible after cooking.
Deep frying comes with unique hazards. Be sure you know what you’re doing, and be prepared for slip-ups. And temperature control is key for good results. If using anything other than a system that automatically maintains a precise temp, do NOT leave oil unattended over heat.