Wash the rose hips and remove the stems and the dried part on top.
Measure 5 cups of rose hips, then add them to a clean saucepan. Add orange slices and cover with 4 cups of water. Simmer for 15 minutes.
Mash rose hips during the last 5 minutes of cooking to extract their juices. Strain pulp through a strainer, set over a large measuring cup. Reserve rosehips.
Pour strained liquid through a soup bag to clarify it even further.
While the rosehip juice is straining, add reserved rosehips back into the same pot and cover with 2 cups of cold water. Simmer for 15 more minutes.
Repeat the straining process, first through a strainer, then through a soup bag, until you have clear juice.
Add rosehip juice, sugar, and rose water to a clean pot. Stir over medium heat until the sugar dissolves. Simmer for 5 minutes or until thickened to your preference.
Skim foam if necessary. Cool the rose hip syrup before pouring it into a 16-ounce bottle using a funnel.
Notes
If using less rosehips, use the following ratio: For every 1 cup of juice, add ½ cup of sugar. I had 3 cups of juice, so I used 1½ cups of sugar. If you don't mind adding more sugar, you can use a 1:1 ratio to make a simple syrup, or up to 2 cups of sugar for every cup of juice, which will yield a rich, shelf-stable syrup.
If you don't have soup bags, you can also use cheesecloth, muslin, or a fine sieve to strain the syrup.
Rose Water is used throughout the Middle East in various sweets, including baklawa. However, a little goes a long way, so use it sparingly.
Some recipes call for removing the seeds and tiny hairs from the center of the rosehips before boiling them. However, it's not necessary for this recipe, since we will be double-straining the rosehips and liquid before making the syrup.
To can this syrup, fill sterilized jars with the hot syrup, leaving ¼-inch headspace. Wipe the rims and tighten the lids/rings. Process in the canner for 10 to 20 minutes, depending on your elevation.