Combine ½ teaspoon calcium powder (from the small packet in the box of Pomona’s pectin) with ½ cup water in a small jar. Screw on a lit and shake until well-combined. You'll have more than you need for this recipe. Store the excess in the refrigerator for use in making additional jam or jelly recipes.
Wash the jars you'll use, making sure each is clean and free of nicks in the rim, which could impede sealing.
Wash the lids and rings in hot soapy water. (If you're using non-Ball brand lids, prepare as suggested by manufacturer.)
Place empty jars in a canning pot or large stock pot with enough water to cover by an inch or two, cover pot, and set on high heat. It can take awhile for the water to heat, so get it started before you begin making the recipe.
MAKE THE TANGERINE MARMALADE
Chop the fruit by hand or use a food processor to pulse it into a pulp. Alternatively you can start with the tangerine sections and use an immersion blender as the mixture is cooking.
6 cups tangerine segments
Measure the tangerines, tangerine juice, ginger, and calcium water into a large saucepan; bring to a boil.
Meanwhile, combine the sugar with the pectin until it's thoroughly combined.
3 cups granulated sugar, 4 1/2 teaspoons pectin
When the tangerine mixture comes to a boil, stir in the pectin and sweetener, stirring vigorously for 1 to 2 minutes to dissolve the pectin while bringing the jam back to a boil.
Remove from heat when the marmalade boils. Stir in vanilla and zest.
1/2 cup tangerine zest, 1 tablespoon vanilla extract
CANNING THE MARMALADE
Ladle hot marmalade into quarter-pint, half-pint, or pint sized jars, leaving 1/4" head space. A canning funnel makes this easy.
Wipe jar rims to remove any jam that may have spilled. A clean rim is essential to a good seal.
Set jar lids in place. Screw bands on finger tight.
Use a jar lifter to gently submerge jars into hot water in the canning pot. Water should cover the top of the jars by an inch. The water will cool somewhat in reaction to the addition of the jars. Return the water to a simmer and then set the timer.
Process for 10 minutes 0-1,000 feet altitude; add another minute for every additional 1,000 feet in elevation.
Remove jars from water using the jar lifter and transfer to a solid, towel-covered surface. Allow to cool for 24 hours.
Check seals. Lids should be solid and pulled down tight. (if they flex and pop, the jar didn’t seal; put unsealed jars in the refrigerator and use those first).
Remove rings and wash outsides of jars. Store in a cool, dry place.
Notes
This recipe is made using Pomona’s Universal Pectin. This is the only pectin I use anymore as it allows me to use much less sweetener. The standard pectin brands use an obscene amount of sugar in my opinion, often requiring equal amounts of sugar and fruit! This product uses a low methoxyl method and calls for using two different ingredients, which are included in the box: pectin (the large packet) and calcium powder (the small packet).
This recipe will be more like a tangerine jam — and somewhat less bitter — if you opt to leave out the citrus skins.
To use the peels, use a fruit peeler to remove just the zest — the orange part — of the peel from about 5 tangerines. Avoid the white pith, as this causes excessive bitterness.
To prepare the tangerines, peel and remove as much of the white pith and membranes as possible. Once peeled, slice the fruit in half to reveal the seeds. Remove as many seeds as possible, but know that you’ll still likely find a few floating in the fruit mixture as you’re cooking it! (Use a spoon to lift those out.)
This recipe measured at a pH of about 3.0, putting it well into the “safe” zone for water bath canning. The Hawaii Master Food Preservers suggest a pH of 4.2 or lower in the tropics. In other regions, the recommended pH is 4.6.
Boiling lids or heating above 180°F as once recommended can damage the sealing compound.
Hot tip: Boil some extra water in a saucepan or electric kettle as you’re working. If you need to top off the water in the canner, you won’t cool down the water too much.