The Single Ingredient That Rescues Crystallized Honey
Honey is perhaps the easiest to use when it's syrupy and smooth, but after a while, it'll develop a clumpy crystalline consistency. This is simply a natural occurrence that happens over time to the sugar in the honey. While you might be tempted to throw crystallized honey away, the truth is it isn't a sign of spoilage and is still perfectly safe to consume. You can stave off crystallization by storing it in a cool environment, but you can't fully prevent it from happening.
While you can use up crystallized honey by turning it into whipped honey, it's actually possible to restore crystallized honey to its original consistency. However, you do need to add an ingredient to it: corn syrup. The best way to go about it is to warm up the honey so it's easier to mix, then stir in the corn syrup. You'll only need about 2 teaspoons of it per 1 cup of crystallized honey, and once thoroughly combined, the honey will reobtain its smooth texture.
How it works
Sugar crystals form in honey when there is nothing to prevent the glucose molecules from sticking together. Usually, the water naturally found in honey serves that purpose, but over time it evaporates. To de-crystalize honey, something else has to act as a barrier. You might assume you could just add more water. However, even though it'll remove the crystals, it may set the stage for mold and bacteria to proliferate. it could also make the honey runny in the process, not syrupy. This doesn't happen when you add corn syrup to it.
One of the building blocks of corn syrup is maltotriose — a sugar molecule like glucose, but a much longer one. Maltotriose keeps the glucose molecules in the honey separated so that they're unable to form sugar crystals. Without these crystals, your honey will be smooth. While corn syrup is highly effective at restoring the texture of honey, it's worth noting that it can affect the taste. Light corn syrup is often flavored with vanilla while dark corn syrup includes molasses, which is known for its caramel-forward taste.
Will it ever recrystallize?
The most common method of smoothing out crystallized honey is to heat it up. Sometimes this works well, but only if there is still some water that hasn't evaporated from the honey. The upside to this method is that it doesn't affect the flavor of the honey, as it doesn't require any additional ingredients. Unfortunately, the honey will eventually recrystallize. This is why corn syrup is the better option, at least in terms of texture.
Unlike water, the sugar molecules in corn syrup won't just evaporate over time. Therefore, there will be something that keeps the glucose molecules in the honey away from each other, ultimately preventing them from turning into sugar crystals. The effects of this are indefinite, and both honey and corn syrup have a long shelf life. Pure honey never goes bad even though its quality might decline, and the same can be said about corn syrup. Adding corn syrup to crystallized honey might affect the flavor and texture, but you don't have to worry about it spoiling any faster.