Liquid Glucose is a solution of glucose suspended in liquid and sold in jars or tubs. Many companies manufacture glucose in powdered form to which water can be added to make liquid glucose, to make transportation of this product easier. Liquid glucose is available from a variety of sources, depending on how one intends to use it. Medical suppliers sometimes carry it, as do some grocery stores, especially stores with a large baking section.
This monosaccharide is produced through the processing of starches such as corn and wheat. Glucose has a famously strong sugar flavor, and it plays an important role in the human body in addition to being very useful in the kitchen. Liquid glucose is an extremely pure form of glucose which has a concentrated flavor. The strength means that people must use it carefully, as it is easy to dispense too much for a particular application.
In cooking, liquid glucose is used as a sweetener in a range of foods. This product does not crystallize, sweetens evenly, helps to preserve food, and has a very low freezing point, making it appealing for things like candy and ice cream.
European recipes tend to call for liquid glucose more commonly, and it is more readily available in European stores for this reason. Corn syrup is similar in nature, and can be used as a replacement if liquid glucose is not available, although the recipe may come out slightly differently due to natural variations.