Sooo... I left my butter on the stove too long and burnt my ghee :o( The milk solids at the bottom of my pan were black, I filtered out the butter fat and it is a brownish-honey color. It tastes okay... can I eat it? It was three sticks of pasture butter so it would be very sad to toss it.
I know I know, my own fault.
That sounds like browned butter. It's really delicious. (In my pre-paleo days, I used to eat at Spaghetti Factory ALL the time. They use browned butter in some of their dishes.)
There's question of whether or not the 'browing' actually creates carcinogens. With starches and some other foods, acrylamides are the concern, which is still being reseached. Basically the main things that MIGHT be a concern are oxidized cholesterol and damaged fats. Butter does contain a very small amount of non saturated fats (and pasture butter does contain some omega3), but it's almost purely saturated so I really don't think you damaged very many fat globules. I'd say the over-oxidized cholesterol could be the only possible concern here.
I know I purposely brown my butter. While there is the whole issue of browning and cancer causing chemicals I find the improvement in taste is worth it for me.
I would probably use it, but only with strongly flavored dishes.
I'd say if it hasn't altered the taste too much it should be ok! I have seen a few bits in mine brown darker than others, I guess it only takes seconds but if it doesn't have a burnt taste it should be ok....its only fat!
What matters is to what degree the fat oxidized. If smoke was wafting up from the ghee, it's well into the process of oxidation, and is no longer safe to eat.
For more details, read up about smoke point