I'm hosting a dinner party tonight and wanted to make a marsala sauce that call for demi glace. Does anyone have a recipe that doesn't take 20 plus hours to make the beef stock?
Demi-glace is a reduction combining brown sauce with veal stock. It needs to reduce by half. Unless you buy the stock already made there really isn't a short cut.
Call around to some quality delis - they might have some. Our local market soup shop (like the guy in Seinfeld ) has Demi glaze in the freezer.You cannot boil down some soup stock or conssume because it is all salt and not the real deal.On the other hand, toss some Marsala in with the au jus and only you will know.
Agree with the others that, unless you're buying ready made demi, there's no such thing as a quick version.
If you've never made it before, though, I highly recommend going through the process. It's not all that labour-intensive or ingredient-intensive, just elapsed-time-intensive. It freezes very well so you can make it a couple times a year and have plenty on hand to add to soups, stews, sauces as needed for body and flavour.
Cook's Illustrated has a short cut recipe for demi. They use it in a Steak Diane recipe.