Essential Ingredient: Glucose Syrup

My master's thesis has been handed in, woohoo! Now, back to the kitchen to make an absolute sugar craft staple: glucose syrup.

Glucose syrup is a handy ingredient to prevent sugar from crystalising in recipes like caramel or chewy sweets, and it's also a good substitute for sugar in frozen desserts. In the United States, corn syrup occupies this role, and often here in Ireland people reach for golden syrup in its place. Because, oddly enough, glucose syrup is very difficult to gets your hands on.

I remember a time when you could get it from the pharmacy, and in small tubes from the baking section of the supermarket. But now, you can only get it online. Luckily, it's very easy to make.

In a large, heavy based saucepan, cook a pound (455 grammes) of sugar with 4 fluid ounces (120 millilitres) of water and a tablespoon of lemon juice. Cook on low, stirring only until the sugar dissolves. Up the heat to medium low, and cook slowly without stirring until it reaches 114 °C (237 °F). This could take about 30 minutes or more. If there are any grains of sugar on the sides of the pan, wash them away with a pastry brush dipped in hot water.

Turn off the flame, and allow to cool down completely without being moved, bumped, or disturbed. Once completely cool, transfer to a clean, sterile jar without scraping the sides of the saucepan; you can scrape the bottom. Scraping the sides would reintroduce sugar crystals and be the ruin of your syrup.

Glucose syrup will keep for up to a month in a cupboard, but after that it could start to crystalise.