By definition, a successfully prepared syrup is thick. But just how thick your syrup is depends on its key ingredients, your personal preference and, of course, correct preparation. When you have syrup that's overly runny, choose a technique or ingredient to solve the problem, then enjoy your stack of pancakes.
Reduction, a technique that involves slowly heating a sauce or syrup until it reduces in volume, relies on evaporation to remove some of the liquid. Use this method to slightly thicken a runny pancake syrup. Heat your syrup in a saucepan on low heat, stir it occasionally and watch it carefully until it reaches the consistency you prefer. Use this method to make an elegant balsamic syrup topping that's thick enough to spoon over a couple of lamb chops. Just heat balsamic vinegar in a saucepan over low heat until it thickens.
Bring on the Heat
The more heat to which you expose a simple sugar syrup, the thicker it will become. If your syrup remains overly runny, insert a candy thermometer to check its temperature. A syrup thick enough to glaze meat or a cake -- or cling to pancakes -- needs to reach a temperature of between 223 and 230 degrees F. Turn the burner up if the temperature is below that point. Don't overboil the syrup, however. Once it reaches 241 degrees F or above, it becomes more suitable for frosting and candy making.
Pack in Pectin
If you like your fruit syrups on the thick side, choose the main ingredient carefully. Using pectin-rich fruits results in a naturally thicker syrup. Berries are among those that are richest in pectin; turn any kind into a thick syrup for pancakes, waffles and ice cream. Blueberries, in particular, will produce thick syrups, because they are both low in natural juices and high in pectin. Start by simmering crushed berries in a small amount of water, then draining them. A 1-to-1 ratio of juice to sugar, gently boiled, will result in nice, thick syrup.
Spoon on the Sugar
When canning fruits in syrup, you have the option to make syrups ranging from extra light to heavy. Heavy syrups are extra sweet as well as thick, making them useful for counteracting the taste of sour foods like sour cherries. The amount of sugar you use in this simple syrup determines its consistency. For a thick, heavy syrup, use equal parts sugar to water, then boil them together until the sugar is dissolved. An ultra-light syrup requires a 10-to-1 ratio of water to sugar. For canning, add the fruit to the pan after the syrup is made, then ladle the contents into jars.
Add an Agent
Cornstarch is the most common additive used for thickening syrup. Add the powdered ingredient sparingly, however, because the jewel-like tones of fruit and maple syrups can become cloudy or grainy with excessive amounts. Before adding cornstarch to the syrup, mix it with water in roughly equal parts. After this slurry is well combined, pour it into the simmering syrup. Start with a small spoonful of the cornstarch slurry, adding more only if needed.
The Cook's Book: Techniques and Tips from the World's Master Chefs; Jill NormanCook's Thesaurus: ThickenersMing Tsai: Thickening: Syrup, Roux, SlurryFine Cooking: Fresh Berry SyrupBall Complete Guide to Home Canning; Judi Kingry and Lauren DevineEpicurious: Baked Figs in Lemon SyrupEpicurious: Rosemary Lamb Chops with Swiss Chard and Balsamic Syrup