So, a call was made for artisans to provide a dozen items each that their Majesties could use for largesse. It can be difficult as a cook to help with these things. Most food items have a limited shelf life. Canning was invented in the Napoleonic era, well after the renaissance. Right at the end of the renaissance, we see recipes for marmalades that are recognizable as similar to modern ones. They were not canned, but rather stored in boxes. As a highly concentrated paste of sugar and pectin, they should probably be sterile, as long as they don't get wet.
For the challenge, I decided to make a set of jars of marmalade from a period recipe. I looked at several, then decided on the one by Hugh Platt, published in 1602. I did alter it based on other recipes from around the same time, and in line with modern practice. I did can it with a modern water bath method, for food safety reasons.
It is a supremely simple recipe, with only three ingredients: oranges, sugar, and apples. I used juice oranges, as they were cheaper, and since I wanted to maximize juice/pulp, rather than having pretty supremes. I used granny smith apples, because I wanted the tartness, but next time I will probably try it with a mealier apple, as the apples are supposed to disintegrate, and the granny smiths never did, even after 3 1/2 hours of simmering.
One redactor I read suggested the apples were there to stretch the expensive oranges. That is a possibility, but I think there is a more practical reason: pectin. While the cooks of the day didn't know of the existence of pectin, they did know that certain fruits, cooked down with sugar, would form a thick paste. Quince was known to do this by the Romans, and I'm sure that similar properties were noted with other high pectin fruits like apples and pears.
The original recipe was: TAke ten lemmons or orenges & boyle them with half a dozē pippins, & ſo draw them through a ſtrainer, then take ſo much ſugar as the pulp doth wey, & boyle it as you doe Marmalade of Quinces, and then box it vp.
Don Avenel's Renaissance Marmalade
12 juicing oranges
approximately 4 3/4 lbs. sugar
6 granny smith apples
Using a vegetable peeler, remove the skin from the oranges, being careful to not get any of the white pith underneath the skin. Fine julienne the peel. Set aside.
Using a sharp knife, remove the white pith from the oranges, and cut out the sections, being careful not to get any of the inner membranes. Remove any seeds. Squeeze all the juice you can from the core, then dispose of the core. Set aside juice and segments.
Peel, core, and slice apples.
Combine orange peel, segments, juice, and apple slices. Weigh mixture. Mine came out to 4 3/4 lbs. In a large stock pot, combine mixture with the same weight of sugar. Stir to dampen sugar. Place over medium low heat. Bring to a simmer. Simmer gently until sugar is dissolved, and peel and apple slices are soft, about 3 1/2 hours.
Can marmalade using water bath method. Process jars for 10 minutes. Makes 12 half pint jars.