Orange jelly
The recipe which I report below is taken from Science in the kitchen and art of eating well , famous text by the gastronome Pellegrino Artusi.
It is a sweet: orange jelly in frost.
Here is what it says:
“Sugar 150 grams, isinglass 20 grams, 4 deciliters water, 4 tablespoons Alkermes, 2 tablespoons Rhum, a large sweet orange, a lemon.
Put the glue in springs and changing the water once, leave it for an hour or two.
Boil the sugar in half of the aforementioned water for 10 minutes and pass it through a diaper.
Squeeze the orange and lemon in this syrup, passing the sauce through the same diaper.
Remove the glue already found and let it boil in the two deciliters of the remaining water and pour this too into the said syrup.
Add the Alkermes and Rhum to it, mix everything and when it starts to cool pour it into the mold kept on ice in summer and cold water in winter.
The molds of this sort of cake are all made of copper with spiers, some with a hole in the middle, others without, in order to obtain a beautiful effect on the table.
To mold it well, lightly grease the mold with oil before pouring the mixture and then dip it for a moment in hot water or rub it with a boiling rag.
Isinglass is not harmful, but it has the drawback of being quite heavy on the stomach " .