I add two quarts of hot tap water to a gallon container, add a teaspoon of citric acid crystals, shake, then add granulated sugar until the gallon container is nearly full (I leave a small air bubble so their is space for the solution to mix when I shake it). Then I install the cap and shake vigorously until the sugar is dissolved. Then I add it to hives/feeders that appear they can use it.
This may not be 1:1, but it's close enough for me and my bees. The acidification seems to help preserve this solution, more than once I've had a gallon or two, sit idle, outdoors from spring til autumn, without fermenting or spoiling in any way - so it's the first syrup I use when it's first needed again. I'm not really sure what keeps my syrup from spoiling, each spring, I usually have some syrup left over from that winter's feedings, it's only recently that I began regularly acidifying it, yet none have ever fermented or spoiled at all - I don't really know why.