But managed to salvage it! “theboylilikoi' writes: I make my mac and cheese with caramelized onions. I was on a time crunch, so I was going to make my 15 minute caramelized onions in which you add a pinch of baking soda to make it break down and caramelize much faster, but here's where things got interesting. I was making a double batch of mac and cheese, so I was caramelizing four onions. I decided, against my better judgement, to put a bunch of baking soda in as opposed to just a pinch or two and ended up adding closer to about 1/2 a teaspoon or more of it. Much to my surprise, my onions totally liquified in the pan like some sort of onion applesauce! However, making the best of the situation, I attempted to reduce the onion liquid down really far and caramelized that in the process. In the end, I was actually left with a really deeply caramelized onion paste that was intensely flavored. I then took this onion paste and actually just melted it into my cheese sauce for my pasta and it turned out fabulous! Anyways, I just thought I'd share this story. Take it as a warning to not add too much baking soda, or as an excuse to experiment with making onion paste. Either way, know that adding more baking soda than recommended to your caramelized onions you get onion soup, apparently.