[Note: I wrote this last year but let it languish in draft form until now; Dad and I have eaten our way through about half of what I made and it will be time to think about putting up another batch or two soon.]
I've been making small batches of preserves (this LA Times article, "Making jam in small batches (with big pleasure)" has been helpful with that) and stockpiling fruit that Mom has been cultivating. Dad and I enjoy tart orange marmalades with lots of peel, which are hard to find commercially in Hawai'i (believe it or not, Safeway Select brand Seville Orange Marmalade - the one that lists oranges as the first ingredient - is the best we've found in the stores here). Sometimes the way to get what you want is to do it yourself, right? This year is the first year that I've been able to do marmalade with Mom's citrus for a couple of reasons, one of them being that at this point, all of the children and grandchildren are living elsewhere and it's usually just Mom and Dad at home. It would have been next to impossible for Mom to have a surplus of fruit even just a few years ago - we would have been eating it right off the trees. She's also been able to spend more time gardening now that there are no children to tend to (and I think Mom likes it that way - plants don't talk back, ha ha).
I've been out there on the weekends lately, doing some home renovation work for them (4 kids will really take a toll on a house), doing prep work for my brother's wedding, and going through Mom's fruit harvests. I've adapted a recipe from John Thorne's book Mouth Wide Open (Maximum Marmalade), which uses sliced fruit that has been macerated in juice from additional fruits. The best-looking fruits get sliced and the not-so-great fruits get juiced and so far that has been working out. Stored in the freezer until I have enough fruit and time to make a pint or two, I've made three batches so far and I think I've worked out the right proportions of fruit to sugar to suit my taste and Dad's. I'm also hot-water canning so that we'll have a supply all year, hopefully.
If you try this recipe, keep in mind that it's more of a general guideline and I've been aiming not only for my particular preference in flavor, but also for the types of citrus I'm using. A big part of the flavor for me is the familiarity of it - the taste is distinctly of the citrus fruits Mom grows and that I've consumed for decades. I don't use additional pectin, so some batches don't get as thick as others (hence using the instant-read thermometer - "jelly test" and "sheet test" don't work so well for me). The amount of sugar varies depending on the sweetness of the citrus fruits, and sometimes I use local honey for part of the sugar. Mom has yuzu (citron), limes, sweet oranges, calamansi (sour oranges), grapefruit, and jabon (pomelo/pummelo). They aren't all in season right now, so the batches I've made have been mostly sweet orange with limes, calamansi, and yuzu. I get started at least the night before so the fruit can sit in the juice and sugar for several hours. This does not seem to be strictly necessary; I made a batch right away once and the results were certainly edible but the peel didn't get quite as tender.
This recipe presumes that you are already familiar with making jams and jellies and hot-water canning (there are a lot of resources available online and at your local public library if you are not). If you don't want to can it, you can just pour it into clean glass jars, ignore the "process for 15 minutes" and store it in the refrigerator.
1 kg sliced citrus and juice (when the fruit is in a bowl, I add enough juice to cover the fruit)
700 g Maui gold sugar (this has a higher molasses content and adds more of a caramelized flavor to the finished marmalade)
muslin jelly bag or cheesecloth
5 eight ounce (half-pint) canning jars with lids, sterilized (you might wind up using only 4 jars - seems to depend on how much liquid evaporates during cooking)
wide-mouth funnel (because getting boiling hot marmalade on yourself is no fun at all, ask me how I know)
Quarter and thinly slice the best-looking fruits into a bowl (Dad and I like a mix of thick and thin - most get sliced about 1/8" cm thick, some get sliced 1/4"/.6 cm thick). While slicing the fruit, remove any and all seeds and set aside. Whatever you wind up with, put into a jelly bag or wrap up in the cheesecloth and secure it. This goes into the bowl of sliced fruit and then saucepan along with the fruit and gets removed at the end (this is to extract as much pectin as possible). Juice the rest of the fruits and pour over the sliced fruits. If there isn't enough juice to cover the slices, add water. To make small-batching easier, I weigh out the sliced fruit and juice as I go, so that each freezer bag or container is 1 kilogram (whatever is left over stays in the freezer until the next round of slicing and juicing).
Add the sugar to the bowl of fruit and juice, cover, and leave in the refrigerator for several hours or overnight.
In a large saucepan, heat the fruit and sugar over medium heat, stirring frequently to prevent sticking and burning. Cook to 220 degrees Fahrenheit. Remove the bag of seeds if you have one in there. Pour into jars, leaving 1/4"/.50 cm clearance. Process for 15 minutes.