Many will likely inquire about the use of corn syrup and if it’s necessary. Corn syrup prevents crystallization so I use it because of the lengthy cooking and reduction of the syrup. I did not try them without using it and you can read more at
Why and When to Use (or Not Use) Corn Syrup.
Note that this process takes about a week, although it only requires a few minutes of tending each day. Very important to remember is that as you’re cooking the citron in the syrup, especially as the syrup reduces and thickens during the last few days, monitor the citron and turn them wedges gently, to make sure they are getting evenly candied and not burning on the bottom.