Milk fresh from the grocery store doesn't have a distinct smell so if you're smelling something atypical, it's a sign the milk might be on its way out. That said, I still drink it unless it's actually sour. Does the milk still taste like milk should taste? I think it's fine. I don't go by the date, either. Organic milk tends to last a lot longer than the date on it, and I don't throw out good milk.

I totally agree with Pi. Smell test, taste test. If it isn't sour, you're good. When you taste it, your body will let you know if it's bad.

Also, I know this might be an over-obvious question, but do other things in your fridge smell off? I've been getting a fruit and veggie delivery, which while awesome, has distinctly changed the smell of everything in my fridge. Nothing smells rotten or sour, but just...off. Organic... I guess that means it's time for a box of baking soda!

Another thought, my fridge sometimes overfreezes and that definitely makes milk taste off even if it's fine. Good luck!

My dad has a trick that he'll use: if the milk is questionable, he will pour some into a clear glass and swirl it. If he sees a bunch of little (we're talking almost pin-tip sized) bubbles going down the side of the glass, he considers it bad and tosses it. I think he is checking for the number of bacterial colonies, and as weird as it sounds, I have tried the same trick on fresh milk but have noticed far fewer, and in some cases 0, bubbles. Obviously, it is subjective, but I swear it works!

My parents grew up in Fiji 40-60 years ago without refrigeration or most of our modern conveniences. But they had a cow :-) My mom told me that the best way to check is to boil a small sample. She said that if the milk was bad, it would curdle when boiled. I have no idea if it really works or is scientifically accurate, but I generally do as my mom tells me when it comes to food.

Incidentally, I recently learned a good tip from a refrigerator repairman. If you want to know whether your fridge is keeping your food cold enough, don't go by those thermometers you hang in the fridge. They measure the air temp, but not necessarily the food temp. Take the temperature of a root vegetable that has been in the fridge for a few hours. He pulled out a carrot and stuck in a probe thermometer.

Hi-
Thought you might find this article from Bon Appétit illuminating:
What the Irish Ate Before Potatoes: BA Daily
http://www.bonappetit.com/blogsandforums/blogs/badaily/2013/03/what-irish-ate-before-potatoes.html
Thick milk, bubbling yellow milk, bog butter...maybe throwing it out isn't what Finn McCool would have done

I've bought light cream from our big supermarket for years now and a shocking number of them (going on half a dozen) have had perfectly good expiration dates but were rancid when I opened them up. We concluded it was being stored at the wrong temperature at the grocery store. Trust your nose, and if it happens more than once make sure your fridge isn't at the wrong temperature.

The real question is, how "bad" is "bad" milk? I mean, do people ever get really sick (or even die) from milk that's spoiled? If not, then I would just go by how it tastes and not worry about it. I'll say that now and then I'll smell a carton of milk or half-and-half and it smells the very tiniest bit "off," but then when I taste it it taste fine--and I've always assumed the off smell was from the little bits of milk/cream that kind of clump around the opening of the carton...

I am totally with Cooking Wife's mother. Boil a bit of milk and you will instantly know. I have done it many times and it always works!!

milk absorb lots of smell, so if your milk isn't tightly lid, milk may smell from all the other food in your fridge. To figure out if the milk has gone bad, yes boil them. Easiest is just microwave them for a minute or so and if it curdles, don't drink!

Emmi....I've run into the same thing with one particular store in my neighborhood in Tucson. Every time I've bought milk there it's been bad but was nowhere near the expiration date. Then I noticed that every carton in their dairy case was bowed, the sides were rounded out instead of straight. Every one.

I figured that either their case wasn't at the right temp or it sat too long between the delivery truck and the case. I mentioned the problem to the manager and he offered me coupons for my next purchase but the situation hasn't changed. I just don't buy any dairy from them any more, and rarely buy at all there, and always look for straight sided cartons at other stores.

I dropped dead last week after drinking some stinky milk.... Well, not exactly... I've found that some milk that had not really gone bad can smell bad because of the cap/lid, seems to spoil there even when the bulk of the milk is OK.

I freeze almost-going-off milk in small portions (like ice cubes) to use in cooking/baking.

But if it tasted fine, I would probably just drink it, as long as the smell didn't make me want to not drink it.

I don't have a great sense of smell so if i'm not sure if milk is slightly on the turn, then I dribble a small amount into gently running water - if the milk splits into two distinct parts then it's off.

Milk goes off as the bacteria break down the fat, causing separation which is easier to spot if you pour a little into running water as the fat splits off from the water soluble part.

I go by the taste, it's easy to detect even the slightest hint of sourness in milk. So if the taste was ok, I would agree with the others and say that it was something from your fridge, the packaging or maybe even something the cows ate.

I tend to go by the best when used by date as generally within a few days after that, my milk will begin to taste off - and that's with a half gallon being consumed by me only.

It is rare that I have had the problem of milk going bad prior to that date, but then again, I try to buy the freshest date stamped on the container, and my milk comes in plastic bottles with a screw on lid so it's easy to properly seal my milk after usage.

@miabica Wow I think I noticed the same thing now that you mention it. I agree, I just don't trust their dairy products anymore. We still go there for certain things since it's down the street from our house, but mostly we shop at our local market instead of the big chain stores, who don't seem to be paying very good attention to food safety!

Yes, you can get very sick from spoiled milk! The problem is that you have no idea WHICH microbes are causing it to smell "off" unless it was carefully cultured (like yogurt or sour cream) http://www.livestrong.com/article/556719-can-my-child-get-food-poisoning-from-milk-that-was-left-out-all-day/

Most bacteria give off an acid as a by-product, which is probably why bad milk curdles when cooked - I remember that happening to me when I was a barista and we unknowingly got a bad shipment of milk, it turned to cottage cheese in the pitcher.

Milk could also be contaminated with viruses or yeasts, which behave differently than bacteria - but which you REALLY don't want in your system.

Milk is pasteurized for this reason, but it still can harbor enough microbes to "spoil" it if it isn't handled properly. http://www.foodsafety.gov/poisoning/causes/index.html

Better safe than sorry.

Lots of misconceptions in this comments section, or just bad advice! (Also a lot of useful info too!)

As some others say, judging your nose above the expiration date on the bottle (or on most foods) is a good way to get food poisoning. The Use By / Expiration date is a mark of food safety. If there is anything in your bottle of milk that will cause illness, you won't be able to detect it by smell/taste!

But that said, typically, a bottle of milk will expire about 3 days after you first open it. Have a smell of a bottle fresh from the store to give you an example of fresh milk. It should have no real aroma to it.

When milk goes off, you'll begin to get bitter or sour notes coming through a sniff or taste. If you swill a small amount around your tongue, again it should generally taste clean. No bitterness, acidity or off notes. And there should be very minimal aftertaste.

Depending on the cause of the spoilage, you might see a change in the texture of the milk too. It could look thicker or ropey, or it could begin to get thinner or separate (though you'll see that before you need to smell it).

Bugs like Listeria monocytogenes, or Bacillus cereus could be present past the milks expiry date, and you really don't want to dice with those!

Source; Quality manager at a Dairy processor.

tl;dr; Three days after you open is usually your limit.

If three days past opening is the safety limit, my whole family would be long dead:)

I definitely wouldn't risk it if it smelled off - think you did the right thing!

I tend to dump buttermilk or crema into milk that's just on the verge, then use it in baking. As a single person, it's pretty hard to use a gallon of milk before it goes bad, but a quart of milk plus three quarts of buttermilk is a cinch. (For some reason, I really don't like drinking buttermilk, so I'm safe there. I label the milk if I'm expecting guests, though.)