[yareally]

Yep, just look at milk. The newer milk is always in the back. If the expiration dates are too short and you won't be able to drink it in time, just look for ones towards the back and get those instead. I generally don't care though as long as the expiration isn't within a week.

[refurb]

Hackers new tip: Buy lactose-free milk and it will stay good for much longer than regular milk.

I don't consume a lot of milk, and I was getting tired of buying a half-gallon and having go bad two weeks later after I had only consumed 1/4 of it.

Lactose-free milk stay good for a long-time. Most of the time when I check, the best-before date is at least 6 weeks into the future. I've never had the milk go bad even if I've had it for 8 weeks. I'm not lactose intolerant BTW.

The only drawback is that the milk definitely tastes sweeter than regular milk. I'm used to it by now, but I'm sure some people would find it disagreeable.

I'm not sure why it lasts so long, even though there is no lactose in it, there is plenty of other sugars in it. Lactose-free milk is made by using enzymes to split the lactose into galactose and glucose. It tastes sweeter because both of the sugars have a higher perceived sweetness than lactose on a weight basis.

[silencio]

It's because lactose-free milk (or at least the Lactaid brand that I see my roommate drink) is treated at higher temperatures. You can find regular milk that has gone through the same treatment labeled as UHT or ultra-pasteurized, like the Horizon Organic brand and another I've seen at Costco as shelf stable juicebox form factor milk drinks (UHT coincidentally removes the refrigeration requirement too if stored in an appropriate container).

No need to pay extra for the lactose-free variant if you don't really need it and the plain UHT-treated milk is cheaper :)

[jlgreco]

Wouldn't the benefits of ultra-pasteurization go out the window once you open the package, thereby contaminating the milk?

[venomsnake]

There was this Mythbusters episode (pyramids preserving foods) where they sliced an apple in half. The one half rotted fairly quickly at room temperature the other was fine.

Brief investigation showed that there was difference in the initial contamination of the two halves and the results observed.

Modern kitchen and fridge are fairly clean places unless you are a movie bachelor. So opening a milk bottle and pouring a glass won't contaminate too much. And at 4 degrees there is not much breeding activity in bacteria anyway.

[makomk]

Actually, they didn't appear to investigate the cause at all - they just assumed one cut surface must have been contaminated more than the other and changed the experiment to remove the cut surface altogether. Since the mold on the non-pyramid apple only survived on the cut surface, not cutting the apples made sure no mold grew on any of them, and all bar one of the apples (the one from the cube) was perfectly preserved at the end of the experiment.

Was kind of annoying actually; the Mythbusters got so pissed off that their experiment appeared to show pyramids working that they set up their next test in such a way it'd give the same result regardless of whether pyramids or contamination had caused one apple to rot faster before, then held it up as proof pyramids were bunk. While it's really unlikely pyramids can magically preserve food, they should still have been honest and fair in their testing.

[jlgreco]

Regular milk spoils much faster after you open it though. Everything that I can find on the web suggests that UHT milk expires just as fast as regular milk after opening.

[enraged_camel]

Well, the milk fridges are also loaded from behind - unlike regular shelves. So with milk at least it makes sense that the newer stuff would start at the back of the row.