A red Christmas jam built on cranberries and strawberries, spiced with cinnamon, clove and nutmeg and set with powdered pectin.
Forty minutes on the stove for six half-pint jars, with the option of canning them properly if you want them to keep.
Why This Recipe Works
- Cranberries and strawberries are a deliberate pair rather than a festive coincidence. Cranberries are extremely high in natural pectin and acid, which helps the set; strawberries bring sweetness and colour that cranberries alone would not.
- Whisking the pectin with a quarter cup of the sugar before it goes in is the standard defence against lumps. Powdered pectin tipped straight into hot fruit clumps instantly.
- The full rolling boil is not a formality. Pectin only sets after a boil that does not stop when stirred, held for one minute — which is exactly how the boil is defined here.
- Four cups of sugar looks enormous and is structural. In a pectin-set jam the sugar concentration is part of what makes it gel, so reducing it does not simply make a less sweet jam.
Fridge Jam, or Canned
The recipe splits at step 6. Both endings make the same jam, but only one of them is shelf stable, and the choice has to be made before you start.
Refrigerator jam — the simpler route
Ladle the hot jam into clean jars leaving 1/4-inch headspace, cool to room temperature, then refrigerate up to 3 weeks or freeze up to 6 months.
No canner, no sterilising, no processing. The jam is preserved by cold rather than by a seal, which is why it lives in the fridge. Skip step 1 entirely if this is your plan.
Water-bath canned — for the cupboard, or for giving
Sterilise the jars first, ladle hot jam into HOT jars with 1/4-inch headspace, wipe the rims, apply lids and bands fingertip-tight, process 10 minutes in a boiling water-bath canner adjusting for altitude, rest 5 minutes, then cool 12 to 24 hours and check the seals.
Processing is what makes it shelf stable for up to a year. Every detail in that sequence is doing a job: hot jam into hot jars prevents thermal shock, a wiped rim is what lets the lid seal, and fingertip-tight bands let air escape during processing.
You canned it but a jar did not seal
Treat that jar as refrigerator jam — into the fridge for up to 3 weeks.
An unsealed jar has none of the protection processing was meant to provide, and there is no way to tell by looking at the jam. The seal check after 12 to 24 hours is the point of waiting that long before storing anything in a cupboard.
Ingredient Notes
- Fresh cranberries
- 12 ounces, about 3 cups. High in natural pectin and acid, which is why this jam sets reliably — they are doing structural work as well as bringing tartness.
- Strawberries
- 24 ounces, hulled and chopped, fresh or thawed frozen. Twice the weight of the cranberries, which is what keeps the jam from being purely sharp.
- Powdered fruit pectin
- One 1.75 oz packet, whisked with a quarter cup of the sugar first. Powdered rather than liquid — they are added at different points in a jam and are not interchangeable.
- Granulated sugar
- Four cups, split between a quarter cup with the pectin and the rest afterwards. The quantity is part of the set, not just the sweetness.
How to Make It
Set up, if canning
Sterilise 6 half-pint jars and keep them warm. Place new lids in hot water and set up a boiling water-bath canner.
Cook the fruit
In a large heavy pot, combine the cranberries, strawberries, orange zest, orange juice and water. Bring to a simmer over medium heat and cook 8 to 10 minutes, until the cranberries pop and the fruit softens. Mash with a potato masher for a rustic texture.
Add the pectin
Whisk the pectin with 1/4 cup of the sugar in a small bowl, then sprinkle it into the pot while stirring. Increase the heat and bring the fruit to a full rolling boil — one that does not stop when you stir it.
Add the rest of the sugar and boil hard
Add the remaining sugar, cinnamon, cloves, nutmeg and salt. Return to a full rolling boil and boil hard for 1 minute, stirring constantly to prevent scorching.
Finish
Remove from the heat, skim any foam, and stir in the vanilla if using.
For refrigerator jam
Ladle the hot jam into clean jars leaving 1/4-inch headspace. Cool to room temperature, then refrigerate up to 3 weeks or freeze up to 6 months.
For canning
Ladle the hot jam into hot jars leaving 1/4-inch headspace. Wipe the rims, apply lids and bands fingertip-tight, and process in a boiling water-bath canner for 10 minutes, adjusting for altitude. Turn off the heat, let the jars rest 5 minutes, remove them to a towel and cool 12 to 24 hours. Check the seals and store sealed jars in a cool, dark place up to 1 year.
Success Tips
- Whisk the pectin into a little sugar before it meets the fruit.
- Wait for a genuine rolling boil — one that does not stop when stirred — before starting the one-minute timer.
- Stir constantly during that minute. Four cups of sugar scorches quickly.
- If canning, check the seals after 12 to 24 hours and refrigerate anything that did not seal.
Serving Ideas
On toast and scones, and it is very good with cheese or alongside cold turkey and ham. Six jars is a gifting quantity rather than a household one, which is what the canning option is really for.
Storage and Reheating
Refrigerate
Refrigerator jam keeps up to 3 weeks. Properly canned and sealed jars keep in a cool, dark place up to 1 year.
Freeze
Freeze the refrigerator version up to 6 months. Leave headspace, since jam expands as it freezes.
Reheat
Not applicable. If the jam is firmer than you want straight from the fridge, let it stand at room temperature for a few minutes rather than warming it.
Frequently Asked Questions
Can I use less sugar?
Not with this pectin. Standard powdered pectin needs a high sugar concentration to gel, so reducing it gives you a syrup rather than a jam. Low-sugar or no-sugar-needed pectin exists and is designed for exactly that, but it is a different product with its own ratios.
Do I need a canner?
Only if you want shelf-stable jars. The refrigerator version in step 6 is the same jam and needs no special equipment at all — it simply lives in the fridge for three weeks or the freezer for six months.
My jam did not set.
Almost always the rolling boil: either it never reached one, or the one minute was cut short. A rolling boil is one that keeps boiling while you stir it, which is a higher bar than it sounds. Under-set jam is still excellent as a sauce, and can sometimes be reboiled with additional pectin.
