A few posts ago, I asked a question about milk temperature and being able to re use steamed milk, not for the purpose of espresso drinks. But in regards to frappecino, smoothies, or baking. I didn't know better, and there was a wide variety of reactions. Most of the community agreed that it wasn't safe to put steamed milk back into cooling refrigeration because of bacterial growth. A legitimate concern. I quit keeping my excess, which isn't much, and dumped. I said I would ask my health inspector the next time he came around. And lo, he came today for bi annual inspections.

And we passed with flying colors.

And then I asked him the question with provided scenario. His reply?
6 hours. If the milk isn't brought to the correct temperature within 6 hours, then it has to be disposed of.

That doesn't speak for the quality of the milk. But as my health inspector so eloquently put it, his thing is temperature.

Anyway. For quality reasons, we probably won't keep the milk to use again. As we improve, Our waste will be less and less. But, it seems, at least from my health inspector, that it is safe for use.