What to do with sour milk

Every once in a while it happens... you go to take a swig of milk and... ewwww! To me, there are three degrees of sourness:

1. You open the milk and don't detect a bad odor, but after a swallow you have a funny aftertaste. (This can occur even a few days before the expiration date, depending on how cold you keep your fridge.) The milk's not bad-bad. You can either use your coping skills and drink it as is, or disguise the aftertaste with some other flavor... either by adding chocolate syrup or using it in coffee or in cream soup.
2. You open the milk and definitely detect a sour smell. If you use sour milk in cooking it will curdle if brought to high heat right away (examples: pouring it in coffee or macaroni and cheese on the stove), but don't worry! There are some interesting things to do with sour milk if brought to heat slowly, such as baking it in non-yeast (or "quick") breads, sourdough bread, or pancakes.
3. You're afraid to open the milk because there are chunks in it, and toxic gas inside has expanded the size of the container. If you do open it, an incredibly rancid odor overwhelms you, your knees become weak, and you have a difficult time standing for a moment. (This usually happens a couple weeks after the expiration date.) Sorry, you've waited too long to make good stuff. Close it back up and take it to the trash outside; you don't want this in your kitchen garbage can!

The main thing is not to panic when your milk starts to go bad. Like taking lemons and making lemonade, sour milk can be more of a treat than you think!