Here's an interesting snippet that provides some insights into what's going on in sugar beet production:
Carbonatation - Wikipedia, the free encyclopedia
The flavor of the candi syrups comes from Maillard reactions, not from caramelization. Maillard reactions only occur between reducing sugars and amino acids, although some other nitrogenous compounds (like ammonia) will cause similar colors and flavors. Variables that affect the Maillard products are water activity, temperature, time, and pH.
In beet sugar processing, lime is added to precipitate protein. In a nutshell, some amount of sucrose is broken down in the alkali environment, and some amount of protein is broken down into amino acids too. The sucrose is then centrifuged out, and what you have left over is the "candi syrup."
Sucrose is not a reducing sugar. Glucose and fructose are reducing sugars, lactose and maltose also have reducing forms. Amino acids could be anything with protein. I've been using milk and hydrolyzed yeast, but really anything with protein could work. Different amino acids form different flavors at different temperatures and pH. I've read a lot of literature on Maillard reactions, and the consensus seems to be that the type of reducing sugar used has the least impact on flavor, most important being amino acid type, then pH, followed by temperature.
How does this help us make candi syrup? It tells us that adding ammonia compounds, like DAP, will provide superficially similar, but distinct and IMO inferior syrup. From my experiments, I've found temperatures over, say 220* or so to be detrimental to the flavor. With the proper pH and the right protein source, you can get a dark, tasty syrup with virtually no caramelization.
I use almost exclusively dextrose in my syrups to make sure I only have reducing sugars, but if you have the time you could boil sucrose for a long time in an alkaline solution and it should break down, or you can invert the sugar using acid. I prefer to use citric acid, but I've used phosphoric as well. Just make sure you add enough lime after inversion to get the pH up where you want it.
From my experience, any pH from 8-12 or so is where you want it, but keep in mind that as it darkens the pH will drop, so I've been experimenting with adding small amounts of lime milk as it darkens to keep the pH up. I usually start with the pH around 12, and aim for a finished product pH of around 5. It's very easy to end up with a low pH. The flavors made at lower pH aren't as pleasant as the flavors made at higher pH.
The hard thing is balancing all the variables. I've made probably 100 batches of syrup and still don't have a recipe "finished."
