Monday, July 16, 2012

Drank Expired Milk? Expiration Dates are Lies!

Yeah, you heard me – expiration dates are a joke, and a bad one at that. I’ve visited a lot of homes in my life. I’ve stayed with families who eat fried foods three times a day, other families who stick to organic vegetables, and even other families who put pineapples on pizza. But the common factor among every home I’ve visited is the strict adherence to expiration dates.

Why are we so terrified about expiration dates? What could possibly be growing inside dairy milk that’s so dangerous? When we poured ourselves a bowl of cornflakes, did an alien parasite slip into the jug? Or did a mutated strain of Ebola sneak into the fridge, unscrew the cap and set up an ambush?

"I say, don't strike until thou see-est the Honeycomb!"
There’s no exact way of knowing when milk has expired until you use the only foolproof test – sniffing or sipping.

This week, I’m going to be looking into food labels and what they really mean. I’m starting today with expiration dates, I’ll post an article about mysterious food ingredients on Wednesday and I’ll end the week with a post about other deceptive food advertisements.

The Science Behind Milk

We’re told as kids that milk comes from cows, it gets shipped from the farm to the grocery store and that’s all there is to it. I understand why most people don’t bother looking further. It’s just milk, for crying out loud! Who cares about where milk comes from?

Well, I care, because I’m nosey like that.

If you can't trust milk, what CAN you trust?
Most dairy farms have many cows (dozens, if not hundreds) that produce milk. To keep these cows healthy, the farmers mix antibiotics and hormones into the cows’ feed. The antibiotics keep the cows from developing deadly infections, the hormones help the cows to make more of it and the farmer just sits back and watches the cream flow.

Once the milk is collected, it needs to be pasteurized. One method for doing this, popular with the milk used in frozen desserts, is to store the milk in a giant vat and heat it to at least 156 Fahrenheit for 30 minutes. The heat kills off most of the nasty little microbes that hitched a ride from the cows into the milk. From there, the milk is packaged and shipped all around the country.

Notice that I said “most of” the microbes.

Despite the dairy sauna, some plucky little bacterium always manages to survive. It sits in the milk, brooding, wanting to get back at the humans for destroying its kind. Think of it like a miniature Rambo in every glass of moo juice.

"They drew first blood..."
It takes a long time for that bacterium to grow, have some kids and rebuild the neighborhood. Ever notice how milk tastes fresher the day you bought it than throughout the week? The loss of “freshness” is the bacteria eating up the natural sugar (lactose) in milk. The longer it has been since pasteurization, the more time bacteria have to grow in the jug. Eventually, it’s a regular block-party of bacteria, and this leads to the sour smell and taste of expired milk.

So Why Are Expiration Dates Wrong?

Bacteria grow slowly. It takes a long while to build up their numbers after being bumped off by pasteurization. The gradual build-up of bacteria can take much longer than the one-week deadline posted on the jug. In fact, how long your milk lasts depends largely on how you store it.

... can prevent sour milk!
Are you the kind of person who leaves the milk out after pouring a bowl of cocoa puffs? Then your milk will expire faster – the warmth promotes bacteria growth.

Are you the kind of person who keeps the cap on and stores the milk in the back of the fridge? Then your milk will expire slower – keep milk cold, dark and covered makes bacteria work harder to spread.

But the biggest point I want to make is that the date on the carton is not an absolute. The bacteria aren’t sitting around on the bottom of the jug, watching the calendar, waiting for the expiration date to come before they strike. If your milk tasted fine yesterday, it’s probably fine today. If your milk tasted funky yesterday, it hasn’t improved since.

But What if I Don’t Want Bacteria In My Milk?

Sadly, you have no choice. Bacteria get into all of our food, no matter how hard we try. But if you want to go longer between trips to buy milk, there are a couple alternatives you could check out.

Farmers of organic milk do not use antibiotics on their cows. To make the milk last longer, organic milk farmers use Ultra-Heat Pasteurization (UHT.) Instead of heating the milk to 156 Fahrenheit, organic milk is heated to 280 Fahrenheit for about four seconds, killing off more bacteria than normal pasteurization. Organic milk will keep for about a month.

Or, if you really want some shelf-life, switch to soy or almond milk. Not only are these milk-alternatives antibiotic and hormone-free (not to mention other FDA approved nastiness,) but they also last over two months without spoiling. I prefer vanilla-flavored Silk to regular milk in my cereal because it makes every bowl taste like dessert!

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