Citrus Marmalade
This recipe will give you about 6 cups of marmalade. I always make a double batch, since I’m already doing the slicing and cooking, may as well make it count. It adds about an hour or so to the cook time here, but I feel like overall that feels worth it. The extra jars are great to keep on hand, as they make an excellent “little-something” for people you like a lot.
YIELD — about 6 cups
Ingredients
2 1/2 pounds citrus (I used a mix of pink grapefruit, tangerines, oranges, lemons, and two small kumquats which did nothing but delighted me to include all the same)
2 1/2 cups demerara sugar (you can use regular granulated here if you don’t have demerara, I just think it adds something a little special here).
2 1/2 cups granulated sugar
1/4 cup fresh lemon juice
Directions
Using a sharp knife, slice the rind and pith (the white part) away from the fruit of the citrus, just like you’re preparing the citrus for a salad.
Thinly slice the peels (this thickness is a personal preference, but I like to do on the thinner side, about 1/8”. You could do even thinner or go slightly thicker if you like.
Thinly slice the fruit, taking care to avoid slicing into any seeds and removing any seeds along the way; set aside.
Add (only) the sliced peels to a large pot and cover with ten cups of water (I use tap). Bring to a boil and cook for at least 90 minutes, at which point, your water will have evaporated by about half and the peels should be nearly transparent and quite tender.
Add the sliced fruit and return the pot to a boil. Cook until the liquid is reduced by about 1/3, another 45 minutes or so.
Add the sugar and stir to make sure it’s totally dissolved without settling to the bottom (this could caramelize, which we don’t want).
Cook the sugar and fruit together until the contents of the pot stop boiling and start bubbling (not a technical term, but I think of boiling as very fast and viscous, and a bubble as slower and decidedly thicker), about an hour or so.
You may want to skim any egregious foamy bubbles that have formed and are now likely clinging to the sides of the pot— do this by using a regular spoon and skimming them away, just like you’re skimming a stock or broth.
Things will happen quickly at this stage so pay attention here: As the liquid evaporates, the sugars start to reach a temperature that creates that tell-tale “set” (think making caramel or other sorts of confections that require you to cook sugar to a certain temperature). Stirring constantly keeps the temperature even throughout and prevents scorching or caramelization on the bottom of the pan, so stir, stir, keep stirring.
If you’re using a thermometer, cook the marmalade to 220°F, then give it the aforementioned “gel test” anyway by spooning a bit of marmalade onto a plate and popping it into the fridge to see how it sets. If it needs more time, cook a few more minutes and try again. Thermometers aren’t fool-proof!
If you don’t have a thermometer, simply do the gel test. If you’re really not sure if it’s done or not or how much longer go cook it, here is what I will say: a too-thick marmalade ends up tasting like candy, so I always err on the side of cooking less rather than more (better texture, fresher citrus flavor, less sickly sweet). If the worst thing that happens is you’ve got a slightly runny marmalade, I would consider that a win in 2021.
Once your marmalade is just about done cooking, add the lemon juice. Boil another minute or two, then remove from heat. Let it chill in the pot for a little bit (10 minutes or so) before dividing into jars or containers.
Notes
For storage: I like to keep mine in the fridge for as long as it lasts. I can’t quote you an exact lifespan because I still have some from early 2020 that is still going strong, but as I’m sure you’ve gathered, I do not work for the FDA, so take that with a grain of salt.