I just had some of my mom’s leftover spaghetti, and I realized that it always has a slightly more bitter taste in the morning after being reheated. What causes this kind of reaction?

Question

It happens both when stored in pyrex or tupperware.
Ingredients aren’t anything unusual; onions, garlic, hamburger, tomato paste, etc.
Tastes sweeter when fresh off of the stove, but has a more bitter taste when reheated as leftovers.

In: 159

Answer 1

If you put hot food in tupperware with a lid on, bacteria can form on the inside of the lid. It’s harmless but can make the food bitter. Cool it before you cover it

Answer 2

I have been eating homemade spaghetti pretty regularly ever since I can remember being a child and can’t say I have ever had a not-one-off experience where sauce was bitter the very next day.

There have been instances where the cookware, storage device, or reheating solutions have caused issues. If you microwave it in a container that can impart flavor or if you microwave too long or too high and it burns parts of it. Some kinds of dishes are bad in the microwave because they get hotter than the contents and can also burn it. It could also be you have it after coffee or brushing your teeth or eating some fruit or other foods that reacts with it.

But I think my tldr would be to look for local causes that aren’t part of the sauce itself first.

Answer 3

My mom would make a large pot of spaghetti sauce so we always had leftovers. I liked the leftovers better than the fresh spaghetti. She told me that she added a secret ingredient to the leftovers but wouldn’t tell me what it was. I asked years later and she told me the secret ingredient was ketchup.
She added ketchup to leftover spaghetti and I loved it. I sort of felt like a redneck.