If a short rib braise calls for 1 cup of port and two cups of red wine reduced by half - do i have to use port. i don't have any. would you just increase the red wine to 3 cups? what is the purpose of port? should i just buy some - how much does it cost? how long does it last?
I've made braised short ribs three times now from the Balthazar cookbook, which calls for 1/2 cup port and four cups of red wine (for 5-7 pounds of ribs). I've used only red wine (replacing the port with it) and they are delicious. I'm sure the port would add an extra something, but I've received incredible compliments on the meal w/o it. Also, I use purchased chicken stock instead of beef stock, b/c I think it has better flavor.
Not sure exactly how long it lasts but a while (6 months or so) as it has a high alcohol content. Port is a dense sweet wine which would probably add depth to the recipe and make it better, but probably not a necessity. You can find a bottle for about $15 (but I'm not an expert there may be cheaper out there). It's also wonderful to drink (when you have leftovers) either alone or with cheese or dessert.
If you want to mimic some of the flavours that port would add to the dish, throw in some good dried prunes, raisins, and cranberries.
You can just use wine but the flavor will be quite different than intended.
A decent ruby port doesn't have to be expensive at all, certainly under $15, very possibly around $12 if you go to a discount liquor store. Often you can find half bottles as well. Since those hold only about 1 1/2 cups, you won't have to worry about a lot of leftovers.
Theoretically it will last quite a while in the fridge but you're better off freezing the leftovers if you expect to have it for quite a while. (It may not freeze hard because of the alcohol content but don't worry about that.)
The port isn't in the recipe for nothing or for show: it will add distinctive depth, balance, flavor and viscosity to the sauce that mere red wine won't. Substituting red wine for it will not be the same dish, but a sister or cousin dish, as it were.