About refrigerating and freezing sauces
My main question is how long sauce espagnole can be kept refrigerated before it goes bad. I heard that a demi-glace will keep well for up to six months in the fridge, without being frozen. Is this true? Does it also work for sauce espagnole?
What about other mother sauces? Is there a general rule about how long they can wait in the fridge without going bad?
Another thing, this is a silly question but I can't seem to find a clear answer... How should sauces be used after being frozen? (stock, espagnole, tomato, demi-glace...) Do we thaw them in the fridge first? Or can it be heated in a pan straight from the freezer? Is there any health concern about heating frozen sauces?