Add the sugar and agar into a pot and mix well. (It will be on the soft side when it lumps together, so for those of you who like a firmer jello or want to shape it, add 5 g of agar!)
Add about half of the orange juice to the pot from Step 1 and heat.
Warm it up while slowly stirring and when it begins to boil, lower the heat slightly and continue heating for a minute longer.
Stop the heat and pour in the rest of the orange juice to the pot from Step 3. Stir quickly.
Skim off the scum.
If adding clementine segments, place them in the bottom of the cups. You can use fresh or canned!
Since the agar will harden as it cools, pour the mixture into the cups while still hot. (Gently stir before pouring into each cup.)
When they have cooled down, place them in the refrigerator to chill well.
[If using 15 g of gelatin] Add the sugar to the juice and heat to 50 - 60°C. Soak the gelatin in 80 ml of water, add it to the juice, stir to dissolve, and pour it into the cups.
Story Behind this Recipe
I like the texture of thickened agar better than gelatin. This recipe is based off many testings.
If agar isn't boiled, it won't harden so make sure to boil it! If for some reason it doesn't harden when chilled, transfer it back to the pot and boil again. If you boil gelatin, it is harder to thicken, so when using gelatin, follow Step 9.