Milk 'clumping' or curdling after warming in microwave?

[jeromedawg]

Hey all,

We just heated some 1% fat milk in the microwave (it's a new MW too) to find that it clumped or curdled up. We put in there for 30 seconds and it was *not* clumped up cold. However, we're 1-2 days out from the expiry date and the fridge currently is reading at 40-41F (I think the fridge is starting to go out on us so hopefully it doesn't die before the new one is scheduled to arrive on 5/31).

I smelled and tasted it cold before heating and it doesn't smell or taste bad but with the clumping/curdling I'm not sure. Does it sound like it's going bad and should we just toss it?

[MayDay]

Yes, we've had this happen.

It occurred when our fridge was on the fritz and had warmed up.

Now we have a new fridge.

[Smokystache]

Every time I've had milk or 1/2 & 1/2 clump up while being heated, it has been close to its expiration date. The dairy product always smelled and tasted fine while cold, but immediately clumped up upon being heated in some way (and will do this when boiling water for my Earl Grey is added too). Thankfully it may not mean that any expensive device is broken - just need to buy milk a little more frequently.

[renata ricotta]

Every time I've had milk or 1/2 & 1/2 clump up while being heated, it has been close to its expiration date. The dairy product always smelled and tasted fine while cold, but immediately clumped up upon being heated in some way (and will do this when boiling water for my Earl Grey is added too). Thankfully it may not mean that any expensive device is broken - just need to buy milk a little more frequently.

Yes, I'll have half n' half or milk that I've been putting into my coffee for a while with no problems, and then when it's close to or just after its expiration date it will clump when it comes in contact with the hot coffee. I think it tasting fine while being cold just means it's not unsafe yet, but it's in the process of breaking down so it's time for new milk.

[Catbert]

Yep, at the beginning of going bad.  Use up quickly rather than dump. It won't hurt you...well at least it never hurt me.

[sparkytheop]

Yes, we've had this happen.

It occurred when our fridge was on the fritz and had warmed up.

Now we have a new fridge.

This is exactly when it has happened to me.  Fridge was going out, and though it was cold that morning, it had warmed up overnight. 

I'd keep an ice chest for any new food you bring in before you get the new fridge, and seriously question the safety of anything that is in the old fridge.

[fixie]

The proteins in the milk have begun to denature and clump.