Equipment
Large pot (15- 19 Liters or16–20 quart)
Water bath canner
Knife
Cutting board
Mandolin (Optional)
Large spoon or ladle
Canning funnel
Jar lifter
Lid lifter
Half-pint canning jars with lids and rings
Fine sieve or cheesecloth
Dishwasher or boiling water for jar sterilization
Ingredients
Fruit
Strawberries (whole, to prep): about 450–550 g (~1–1¼ lb; roughly 1½ quarts / 6 cups whole berries)
Target: 4 cups crushed (~950 ml)
Rhubarb (fresh stalks): indicate red-stalked if possible
Fresh rhubarb: about 900 g (~2 lb), ends trimmed, cut into 1.25 cm (½ in) pieces
Water for cooking rhubarb: 60 ml (¼ cup)
Target after cooking: 2 cups cooked rhubarb (~475 ml)
Set + flavour
Lemon juice: 60 ml (¼ cup)
Pectin (low/no-sugar type recommended):
Source lists 1 package (or 8 Tbsp bulk), but directions say 1½ packages (~10 Tbsp)
Use: 1½ packages (or ~10 Tbsp bulk) for consistency with the method
Sweetener (choose one approach)
Low sugar (recommended by the directions): 800 g (4 cups) granulated sugar
Reserve 50 g (¼ cup) from this to mix with pectin
Higher sugar variation (as listed): up to 1.3 kg (6½ cups) sugar (not otherwise used in their steps)
Honey option: up to 950 ml (4 cups) honey (same volume as sugar, but set may differ)
Alternative sweeteners: Stevia/Splenda blends — must follow pectin package instructions (varies widely)
Optional flavour
Orange zest: 1 Tbsp (about 1 medium orange)
Orange pulp/juice: 1 orange
Preparation
1. Prep jars + canner
Wash jars and keep hot. Warm lids in hot (not boiling) water.Heat canner water so it’s ready for processing.
2. Prep fruit
Rhubarb: trim ends, peel only if very tough, chop to ½-inch / 1.25 cm pieces.
Strawberries: wash, hull, halve if very large.
3. Cook rhubarb
In a pot, combine chopped rhubarb + ¼ cup (60 ml) water.Cover, bring to a boil, then simmer until tender (about 1–2 minutes after boiling starts).Measure 2 cups cooked rhubarb.
4. Crush strawberries
Crush to 4 cups (not fully puréed unless you want a smoother jam).
5. Measure sugar + prep pectin
Measure 4 cups (800 g) sugar.Remove ¼ cup (50 g) and mix it dry with the pectin (helps prevent clumps).
6. Combine fruit + lemon + (optional orange)
In a bowl, combine:
Cooked rhubarb (2 cups)
Crushed strawberries (4 cups)
Lemon juice (¼ cup)
Optional orange zest + orange pulp/juice
7. Add pectin + bring to a full boil
Stir the sugar-pectin mix into the fruit mixture.Transfer to a large pot. Heat over medium-high, stirring often, until a full rolling boil (can’t be stirred down).
8. Add remaining sugar + boil 1 minute
Add the remaining sugar (3¾ cups / 750 g).Return to a full rolling boil and boil hard for 1 minute.
Remove from heat.
9. Skim foam (optional)
Skim foam for a clearer finish.
10. Test set (optional)
Cold spoon test.If too loose: add ¼–½ pack more pectin, boil 1 minute, retest.
11. Fill jars
Fill hot jars to 6 mm (¼ inch) headspace.Wipe rims, apply lids and bands fingertip-tight.
12. Process (water bath)
Process jars with at least 5 cm / 2 inches of water over lids.
250 ml jars: 10 minutes at sea level to 1,000 ft
Adjust time for altitude per standard water-bath guidance.
13. Cool and store
Cool 12–24 hours undisturbed. Check seals, label, store.
A classic tangy-sweet jam with chunky strawberries and tender rhubarb, set with pectin and finished with a short hard boil.