[Caleb (OP)]

Three months ago I added a drop of chlorhexedine (actually a drop of hibiclens) to a gallon of milk and it stayed unspoiled well beyond its expiration date, much longer than other gallons of milk I have had in my fridge.

Does anyone do this kind of thing regularly? I had read that chlorhexidine has been used for decades as a food preservative in Europe for decades.

Any other suggestions for safe food preservatives?

Yours,

Caleb

[CliffordK]

In Italy, most of the milk is sterilized.  Just buy a case of milk.  Put it in the closet, then grab a liter whenever you wish.  Once opened, put it in the fridge.  Most of my current milk usage is in cooking, so I generally use powdered milk.

No doubt industry is looking for better preservatives, but a lot can be done with merely managing one's food.

[Caleb (OP)]

CliffordK -- Interesting. Very good observation!

Here in the U.S. the milk is pasteurized, which means, according to wikipedia (I checked just now) that the major microbes that could contaminate milk before the expiration date are killed, but the milk is not sterilized as in your neck of the woods.

Almost makes me think that the the agricultural lobby is interested in milk going bad earlier than it the last possible time because that would mean they would sell more... but no, that's crazy talk.

Interesting -- Thanks, CliffordK -- I didn't know that.

Yours,

Caleb

[CliffordK]

Just an observation from earlier travels.
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Some of the people I was with could not get used buying cartons of milk from the store shelves. 

Once opened, it does need to be refrigerated, and will eventually go bad.

Here in the USA, you can buy canned condensed milk which also has a long shelf life before opening.

As far as why the sterilized, boxed milk is not sold in the USA, I really don't know.  I doubt many people are either throwing out large amounts of spoiled milk, or chugging gallons before the expiration date.  Perhaps it has to do with different production, shipping, and distribution networks.  One wouldn't need reefer trailers for transporting the milk, or refrigerators in the stores to sell it.  In some places farmers will breed all the cows for spring calves which could cause a significant impact on winter milk production.  No doubt, August in Italy also has a significant impact on the distribution of perishables. 

[Bored chemist]

Almost makes me think that the the agricultural lobby is interested in milk going bad earlier than it the last possible time because that would mean they would sell more... but no, that's crazy talk.

Or it could be because sterilised milk tastes funny.

[chiralSPO]

One can definitely buy parmalat in the USA. I usually keep a box or two in the pantry as backup, but I do prefer the pasteurized milk, and use that primarily...

[alancalverd]

Sterilised milk is great in coffee but completely wrong in tea. When I was a lad, many households would have a pint of sterilised for cooking and coffee, and a pint of pasteurised for drinking and tea, delivered every day. The public taste for steri may have been a hangover from wartime (it was standard military issue) and with the advent of domestic refrigerators pasteurised became the posh statement. Steri, conni and evap are still popular in the Far East, but nobody puts milk in Chinese tea anyway.