Candied Buddha's Hand Citron

Step 3 Testing for the "Thread Stage"

If you are unfamiliar with the stages of cooking sugar syrups here is the simple explanation. As sugar syrup is boiled, the water in it is slowly evaporated, allowing the syrup to become hotter and hotter. The names of the stages correspond to how the syrup behaves when a spoonful is dropped into ice water. The more concentrated the sugar solution is, the firmer it becomes upon cooling. The thread stage is on the very low end of the spectrum, followed by soft ball, firm ball, and other stages that are not of concern to this instructable. The stages terminate in caramel, which terminates in carbon if you cook it long enough, but I digress.

Candied citrus peel requires the thread stage. At this point when the syrup is dripped into ice water it will form visible "threads" as it falls to the bottom of the glass, but these threads are actually still liquid and cannot be smooshed together into a ball. If you can make a ball of the cooled syrup, you have reached the soft ball stage or perhaps even worse. Candied peel cooked to soft ball or beyond will become super chewy or even hard, which is undesirable. If it happens to you, try to save the mistake by adding a little water back to the pot and cooking it down to the thread stage again. I encourage attentiveness to the process to prevent over cooked syrup.

Conversely, undercooked syrup results in candied peel that won't dry properly and will remain syrupy. Not a bad way to go for an ice cream topping, so stop cooking earlier if that sounds good to you! Undercooked syrup will make swirling clouds when you drip it in the ice water, but no threads.