Citrus & Ginger Cordial

My friend Ben recently gave me a large sack of different fruits. I feared early spoilage, what with limited refrigerator space and only myself to feed, and so set about on ways to utilize at least some of the fruits. Glancing around the net implanted some ideas in my head for a citrus cordial - a syrup mixer for creating drinks. I just made up my own ratios of fruit - I think it would be difficult to mess it up.
Prepare:
-Cut several citrus fruits in half, zest some of them as well. I used 2 oranges, 2 small mandarins, and 5 limes of various sizes-Peel and roughly chop a good amount of ginger
-Measure out about 2 1/2 cups of sugar (I used caster or icing sugar)
Cook:
-Juice the fruit-Mix the fruit juice with the sugar, ginger, zest in a medium pot-On medium-high heat, bring to a boil; lower and let it simmer healthily for a while
-Once it has reduced a bit and started getting more syrupy and viscous, turn off heat-Let cool and then filter out the ginger/zest.
-Store in an airtight bottle and enjoy as you wish
Tips:
-The cordial is quite sweet and so you would only use it mixed with soda water and not anything else sweetened like tonic water. I imagine it will go quite well with alcohol as well. I already used a teaspoon mixed with some boiling water and it resulted in a very nice hot lemon "tea"