Sauce – Marinade sauce bottle left open for longer than recommended – safe to use

It is likely that prior to use there is minimal likelihood of the ingredients separating as the transport and shelf storage of the item is likely considered controlled. Once in a home kitchen, the problem is not with spoilage (there are plenty of preservatives in it), but that storage fluctuations and use may throw the emulsifiers.

Although I am inclined to dismiss the need for refrigerating it, the is likely that across a few million units, a less stable batch may make its way into a hot and then cold and hot and then cold kitchen and the contents would separate.

For big brands, a major focus is to ensure consistency among products in spite of quality or diverse ingredients; hence watery domestic beer (U.S.), Lay's potato chips, and refrigerated chocolate syrup that is harder to use than when stored at room temp.

First thing to try is freezing, possibly in ice cube trays (once frozen, transfer to freezer bag). Freezing has the advantage that you can be confident the food is still safe to consume.

Unfortunately, cornstarch-thickened sauces often don't hold up to freezing. A couple of approaches:

• Thicken only after thawing. Takes more time reheating, but not much.
• Try arrowroot or tapioca starch. You'll get a different look and slightly different texture than you're used to.
• Use "modernist" ingredients for thickening, such as guar gum and/or xanthan gum. The texture is probably going to be different than what you're used to.

Your BBQ sauce is not only low-pH it is also high-sugar. Both reduce microbial growth. It'd be difficult to know how long your pan sauce would last in the fridge without measuring those, and possibly doing lab work.