After talking to Brian Mercer the importer of the amazing Dark Candi Syrup and making multiple attempts to make my own at home, I think I have come up with something that will hopefully be tasty, but doesn't approach the color contribution. I have included this one in my second Belgian Sugar Experiment, so I'll have a more accurate impression of the flavor and fermentability by early November.
1. Take 1 lb of plain white sugar and mix it with 3 cups of water in a heavy bottomed saucepan.
2. Stir to dissolve over medium heat (if the heat is too low there is a chance that the sugar will crystallize on you, so make sure you have rapid bubbling)
3. Monitor the temperature until it hits 285 degrees then add a tablespoon of water.
4. Adjust the heat until it is hot enough that you get bubbles all over the surface of the syrup, but not so hot that the bubbles build way up the pan.
5. Repeat this as needed not letting the syrup get above 285 (This will be a lot easier if you have a thermometer with an alarm). During this process you will smell an amazing range of aromas starting with butter, then moving through rummy and finally to sort of a roasted raisin thing.
6. Once the syrup takes on a nice dark color add 1/3 cup of water and let cool.
What is the point of all this?
Boiling sucrose for awhile in water causes some of the disaccharide sucrose molecules to split (invert) into the monosaccharides glucose and fructose. Some recipes call for the inclusion of an acid to aid the inversion process, but the importer assured me that the only ingredient in his product is refined beet sugar (sucrose).
Once some of the sugar is inverted holding it at around 285 presumably allows some of the newly created fructose to caramelize (caramelization temp of 220), while the more robust sugar molecules glucose (caramelization temp of 300) and sucrose (caramelization temp of 340) remain intact and more importantly fermentable.
The final addition of water allows the finished sugar to remain liquid at room temperature, making it much easier to add to a beer than lumps of solid sugar.
Log:1st attempt: 1 lb sugar, 1 pint water, 1 tsp 10% phosphoric acid, 45 minutes @ 260-275
Result: Way too sour, apparently I used way too much acid.
2nd attempt: 1 lb sugar, 1 pint water, 1 gram acid blend, 150 minutes @ 260-275
Result: The syrup turned out a bit thin and the flavor just seemed flat.
3rd attempt: 1 lb sugar, 1 pint water, 180 minutes @ 260-275 (accidentally let it get up to 310 in the middle of cooking)
Result: Good flavor, but a bit too much char probably from the high temp.
4th attempt: 1 lb sugar, 3 cups water, 180 minutes @ 260-285
Result: Good flavor with less burnt notes than attempt 3, but also not as dark.
I used my 4th attempt in my second sugar experiment. I am happy to report that the portion of the experiment with the homemade candi sugar got just as dry as the other portions. The beer tasted good at bottling time, but it will be a few weeks before I can give a real report on the success or failure of this technique.
Here is a short little video of attempts two (left) and three (right) boiling. You can see just how much the sugar bubbles can build up.