Demi-glace is a serious production, no doubt about that. Unfortunately, finding demi-glace can be as much of a production for many people.

Actual demi-glace – a combination of Espagnole sauce and brown sauce – is hard to find premade (that is, not everything labeled demi-glace is demi-glace. We have found at least one product where the first ingredient is corn oil. We do not consider that to be a meat glaze – no matter how long the shelf-life.)

There are packaged products on the market here and there. Are they here and there near you? Possibly. You can demi-glace in some specialty stores, including many Williams-Sonoma stores. The Whole Foods nearest us stocks it, but was out when we checked in response to your question. We would get out the phone book and call shops in our area before we began driving around.

There are a number of sources online, including Amazon.com, Williams-Sonoma, and Cooking.com. One review on Amazon.com gives a product a low score because it costs more to ship than it does to purchase the product (one reason we don't put much faith in the review system at Amazon), but it is something to consider – buying demi-glace is not for the faint of heart.

Obviously buying it in a 16-ounce container is going to get you a lot more bang for the buck than buying three or six 1.5-ounce containers, but you alone know how much you can use efficiently and how fast. It may be that five small spare containers of demi-glace will meet your needs for the foreseeable future. (And our online research shows that six 1.5-ounce containers cost a little more than $21 right now and a little less than $6 to ship – probably less than it would take to drive to two or three stores hoping to stumble upon demi-glace. We are convinced that few people take their time, trouble, and gas money into consideration when they roll their eyes at shipping costs.)