The thickness of barbecue sauce is important for more than just its mouth-feel. Thin barbecue sauce does not bind to or coat meat as effectively as a thicker liquid does. There are a number of ways to make a barbecue sauce that is the right texture, some are simpler and more effective than others.
Reduction is the simplest way to thicken barbecue sauce. Just heat it and reduce the amount of water in the sauce via evaporation. While it does take longer to reduce a sauce when compared to other thickening methods, it does not require you to dilute the sauce. In addition, reduction does not involve adding extra ingredients.
To reduce your barbecue sauce, place it in a pot and bring it to a boil. Lower the heat and continue at a slow boil until your sauce achieves a level of viscosity that is close to what you want. Remove it from the heat. It will continue to thicken as it cools.
Cornstarch is a powder obtained from the corn kernel’s endosperm. You use it by mixing it with water to form a slurry. While using a cornstarch slurry is not quite as simple as reduction, it can do the job in less time. Place your sauce in a pot. To add cornstarch, first mix it with cold water until it is dissolved then pour the slurry into your sauce. Start with a ½ tablespoon each of cornstarch and water for a cup of sauce. Note that you want to avoid lumps in your cornstarch since these may not break down once the cornstarch is heated. Bring your sauce to a boil and simmer. Within five minutes, your sauce should be noticeably thicker. The more cornstarch you add, the faster the sauce will thicken and the thicker it will be. Keep stirring with a whisk to keep the sauce from sticking to the bottom and sides of the pot.
Note that many barbecue sauces are highly acidic and cornstarch has a way of breaking down in acids. If you are making a barbecue sauce with lots of ketchup or vinegar, you may find that the cornstarch breaks down and does not thicken at all. If you keep adding more cornstarch, this may result in your sauce taking on a chalky taste. Another drawback of using cornstarch stems from the fact that you are diluting the other ingredients. Your sauce will be blander than it would be if you had not used a thickener.
Arrowroot is a starch derived from tubers and is another excellent thickener. Unlike cornstarch, it has the benefit of bringing several nutrients to the dish.
To thicken barbecue sauce with arrowroot, mix a tablespoon of it with cold water to make a slurry and add it to your sauce. As with cornstarch, you should mix thoroughly to prevent lumps. Heat the sauce gently as arrowroot will break down with excessively high temperatures.
Arrowroot has the benefit of having a completely neutral taste and can stand up to acidic liquids, which means that you will not encounter the chalky taste that cornstarch can bring.
Brown sugar is an excellent thickener and will enhance the flavor of your barbecue sauce. The darker the brown sugar, the more molasses it contains. A higher molasses content will give a deeper flavor to your sauce.
Simply add a cup of brown sugar for each cup of barbecue sauce that you are thickening, place in a pot and simmer. Watch it closely and stir frequently with a whisk to keep your sauce from tightening up too much and from sticking to your pot.