I'm in the process of making sugar wax made of heated sugar, lemon juice and water. I have found a ratio that works great when it's heated up to 119 C (246.2 F). It gives me a wax that has the perfect consistency and firmness. The problem is that this ratio and temperature works fine only when making one jar of wax. When I try to scale the volume up (using the same method, recipe and temperature) it turns out different. The more I scale it, the more runny it turns out even though it reaches the same temperature. I'm using the stove (electric) to heat up the wax. I've been consistent with using the same pan and same temperature setting for the stove every time I make the wax.
I'm trying to understand what is happening when combining these three ingredients. Why do I get a different consistency when increasing the volume? (even though I'm using the exact same recipe and reaching the same temperature). What are the parameters that play an important role? Until now I've thought that the volume (as long as the ratio is the same) doesn't matter, as long as it reaches the right temperature. This turned out wrong, and now I'm interested in knowing what is causing it to turn out different.
Does anyone have any experience of something similar? Maybe there is some chemical theories I'm missing? I would appreciate all the help I can get. Thanks!