*snip*
Did you like, do this in front of said-guest? That sounds like the kind of reaction I've gotten when I've done or said something that's embarrassed my parents in public. Privately, my family isn't the kind to quietly let stuff slide only to come back to it hours later, unless they're so pissed they have to stay quiet. We tend to get mad quickly, and make up quickly, because none of us like holding grudges.
I've been told before that I'm pretty good at hurting people with words, and that I don't appreciate the impact I can have on other people. So I'm a little more inclined to believe that you're not really putting yourself in their shoes. It's clear there's tension that's been building for a while, to the point something minor like that sets your mom off. I mean, when your family senses you don't like them or you're just trying to get them away from you as quickly as possible.....yeah, I can see where they'd find that hard to deal with gracefully. Have you tried just leveling with your mom and assuring her that you do care how she feels? That you're not ungrateful, that her happiness is important to you on some level?
I've always been quick to apologize for what I saw wrong in what I did, because mentally I figure I accept responsibility for myself and give the other person their due of my understanding. Which is actually shockingly rare, I've found. You will not often meet non-family or friends who will meet you half way. You can't ever really count on that. All you can do is acknowledge what you did wrong.
And hopefully learn from it. I'm not chiding you, I've gotten shit from my family for being a loner, for my tone, my attitude, my not seeing how those things affect the people around me. At one point it did totally blow up in my face. Trust me, you can't stop ducking your part in how these things turn out because it will eventually bite you in the ass, even as an adult. Your mom may always be manipulative, over emotional, what have you. You may not be able to change that. But at least you can maybe be self aware enough to change to the degree it makes you a better person. And might have the side effect of chilling your mom out and robbing your brother of something to gloat over.
That all starts with an honest apology, at the very least. Not for refusing her making you food...but for
alllllllll the other stuff you know is wrapped up in this. The stuff you kind of admit to knowing is your bad. Don't even ask her for an apology for getting mad at you, because it isn't really about that. It's about letting her you do at least care. At least with my mom, if she has something to apologize for I usually get one in return at some point.
Either way, good luck.