"Bargain" Milk

[Zara]

OK so I was in the grocery and noticed that they have organic milk, near it's sell-by date, for $1.50 a gal!!!!

Is there any reason why AGE of the milk makes it less appropriate for using for cheese?

I was thinking I can take it home, "re-pasteurize" it (is that a word?), and use it like any other storebought milk, right?  Or am I dreaming?

They almost always have some of the organic stuff marked down very cheap, I guess it doesn't sell as fast as it should.

I'm not very experienced with store milk - is there a compelling reason why I should steer clear of this? What else happens to milk as it sits on a shelf besides rising bacteria count? Do other reactions take place over time taht will leave it unsuitable? Would pasteurizing it AGAIN leave it far off center?

[mike_i]

i don't see any reason you couldn't use it to make cheese. I would use it as soon as possible and would not pasteurize it again. You don't want to use ultra pasteurized milk. I buy my raw milk when it goes to half price just about 3 to 4 days before the sell by date.

Mike

[DeejayDebi]

It is always best to use the freshest posible milk but for many cheese it won't matter.

[linuxboy]

It all depends on the milk. Pasteurized milk has very little to none lactic bacteria, but still has putrefactic microorganisms. That's why pasteurized milk will go bad and not sour. Repasteurizing won't do much good.

If the milk is fresh enough that the pH levels are ok and it has a decent ionic balance, you can culture it and proceed, but the warm temp will give the bad bacteria an even bigger opportunity, and at that point, it'll be a war between the lactic bacteria and all the nasties. The nasties leave off flavors, which can carry over to the cheese.

There's nothing wrong with using older milk, but I wouldn't make long-aged cheeses with it. Feta, queso blanco, ricotta, etc all would work well. For longer aging times, all those nasties will give the cheese an odd flavor. When their cell bodies burst, the outcome won't give the pleasant result that lactic bacteria provide.

[MrsKK]

"That's why pasteurized milk will go bad and not sour."

Actually, pasteurized milk does go sour.  Raw milk clabbers - gets thick and tastes sweet, but doesn't sour.

With older raw milk, I have found that it doesn't work well for making mozzerella, but I have never had trouble with it for making other types of cheese.

As the bargain milk has already been pasteurized, though, I can't give any solid advice.

[Zara]

Thanks for all the information. Cleared up some false impressions I had. Next time I see some I'll pick up a gallon and maybe try a simple fresh cheese and see how it goes.

Thanks again!

[linuxboy]

"That's why pasteurized milk will go bad and not sour."

Actually, pasteurized milk does go sour.  Raw milk clabbers - gets thick and tastes sweet, but doesn't sour.

Huh, I wonder why your pasteurized milk sours. Do you mean it tastes sour, or do you mean it turns into yogurt? The milk I get at the store, if I just leave it at room temp, will thicken up, and start smelling bad. I've tasted it before it goes bad, but after it has been at room temp for a day, and it has a slight sour note, but nothing like yogurt or clabbered milk... it's more bitter. Raw milk for me thickens quickly if left at room temp, but doesn't exactly taste sweet... more like a creme fraiche. If I leave it for longer than a day, then it becomes increasingly sour in flavor.

I always thought the difference was because the lactic acid bacteria start dying at lower temps than the putrefying bacteria, and you couldn't get a proper curd set when inoculating older milk because the pH was already lower than fresh milk, and the new lactic acid culture was fighting with the bad bacteria.