Classic rhubarb jam is a celebration of early summer’s bounty, offering a tangy-sweet flavor that’s both nostalgic and refreshing. With its vibrant color and bright taste, homemade rhubarb jam is a simple way to preserve the unique essence of rhubarb for months. This recipe requires just a few ingredients and straightforward steps, making it accessible to both beginners and seasoned home cooks.
Ingredients
- 2 pounds (900g) fresh rhubarb, trimmed and chopped (about 7 cups)
- 4 cups (800g) granulated sugar
- 1/4 cup (60ml) fresh lemon juice (from about 2 lemons)
- 1 tablespoon lemon zest (optional, for extra brightness)
- 1/2 teaspoon unsalted butter (optional, to reduce foaming)
Instructions
- Prepare the rhubarb: Rinse the rhubarb stalks thoroughly and trim off any leaves (they are toxic and should not be eaten). Chop the stalks into 1/2-inch pieces, discarding any tough ends.
- Combine ingredients: In a large, heavy-bottomed pot or Dutch oven, combine the chopped rhubarb, sugar, and lemon juice. If using, add the lemon zest for an extra burst of citrus. Stir everything together so the rhubarb is evenly coated.
- Macarate: Let the mixture sit at room temperature for 30-60 minutes. This draws out the rhubarb’s juices and helps the sugar dissolve, making for a smoother jam.
- Cook the jam: Place the pot over medium heat. Stir occasionally as the mixture heats up and the sugar completely dissolves. Once the mixture begins to simmer, add the butter if using (it helps reduce foaming). Continue to cook, stirring frequently, until the rhubarb breaks down and the mixture thickens. This usually takes 25-35 minutes. Skim off any foam that forms on the surface with a spoon.
- Test for doneness: To check if the jam is ready, place a small plate in the freezer while the jam cooks. When the jam looks thick and glossy, spoon a small amount onto the cold plate. Wait 30 seconds, then run your finger through the jam; if it wrinkles and holds its shape, it’s done. If not, cook for a few more minutes and test again.
- Jar the jam: Ladle the hot jam into clean, sterilized jars, leaving about 1/4-inch headspace at the top. Wipe rims with a clean damp cloth, seal with lids, and screw on bands until fingertip-tight.
- Process (if storing long-term): For shelf-stable storage, process filled jars in a boiling water bath for 10 minutes (adjusting for altitude as needed). Remove jars and let cool undisturbed for 12-24 hours. Check for seals before storing.
- Cool and store: Once jars are cool and sealed, label with the date. Store in a cool, dark place for up to 1 year. Refrigerate after opening.
Tips
- Substitutions: If you prefer a lower-sugar jam, you can use a low-sugar pectin and reduce the sugar to 2-3 cups. Always follow package instructions for pectin.
- Foam control: Adding a small amount of butter during cooking helps reduce foam, making it easier to jar and giving a clearer jam.
- Don’t skip the lemon: The acid in lemon juice is essential for safe canning and helps the jam set properly. Do not substitute with bottled lemon juice unless it’s specifically for canning.
- Storage: Unprocessed jam (not water-bath canned) should be refrigerated and used within 3-4 weeks. Properly processed jars can be stored at room temperature for up to 1 year.
Serving Suggestions
- Spread generously on toasted sourdough, brioche, or English muffins for a classic breakfast treat.
- Stir a spoonful into plain yogurt or oatmeal for a tangy-sweet flavor boost.
- Use as a filling for thumbprint cookies, sandwich cookies, or homemade pop tarts.
- Pair with soft cheeses (like goat cheese or brie) and crackers as part of a cheese board.
- Warm slightly and swirl into vanilla ice cream or cheesecake for a simple dessert upgrade.
Variations
- Strawberry Rhubarb Jam: Replace half the rhubarb with hulled, chopped strawberries for a classic combination.
- Ginger Rhubarb Jam: Add 1-2 tablespoons finely grated fresh ginger with the rhubarb for a spicy kick.
- Vanilla Rhubarb Jam: Stir in seeds from 1 vanilla bean or 1 teaspoon pure vanilla extract after cooking for a floral, mellow note.
- Orange Zest: Swap lemon zest for orange zest for a different citrus profile.
Storage and Reheating
- Unopened, processed jars: Store in a cool, dark pantry for up to 12 months. Ensure lids remain sealed; discard any with broken seals or signs of spoilage.
- Opened jars: Refrigerate after opening and use within 3-4 weeks for best quality.
- Freezing: Rhubarb jam can be frozen in freezer-safe containers for up to 6 months. Leave at least 1/2 inch headspace to allow for expansion. Thaw overnight in the refrigerator before use.
- Reheating: Jam is typically served cold or at room temperature, but if you wish to warm it (for drizzling over desserts), microwave in 10-second bursts, stirring in between, until just warmed.
Frequently Asked Questions
- Can I use frozen rhubarb for this jam?
- Yes, frozen rhubarb works well in this recipe. Thaw the rhubarb completely and drain off excess liquid before weighing and using it. This ensures the jam thickens properly and isn’t too watery.
- Why is my rhubarb jam runny?
- Jam that doesn’t set is usually undercooked or lacks enough acid or sugar. Make sure to cook until the jam reaches the gel stage (220°F/104°C) or passes the cold plate test. Using the correct ratio of rhubarb, sugar, and lemon juice is essential for proper setting.
- Do I need to use pectin?
- No, this classic recipe relies on the natural pectin in rhubarb and the added lemon juice. However, if you want a firmer set or are using lower sugar, you can add commercial pectin according to the package instructions.
- Can I double or halve the recipe?
- You can halve the recipe easily for a smaller batch. Doubling is possible, but larger quantities may take longer to reach the proper consistency and can be harder to monitor for scorching. For best results, make single batches or cook in two pots if you want more jam.
- What if I don’t have a canner?
- If you don’t plan to water-bath can the jam, simply pour the hot jam into sterilized jars, let cool, and refrigerate. Consume within 3-4 weeks. For longer storage, freezing the jam is a safe alternative.
- Is it safe to reduce the sugar?
- Reducing sugar will affect the jam’s set and shelf life, as sugar helps preserve it. If you want to use less sugar, use a low- or no-sugar pectin to ensure a safe and well-set jam. Always follow canning safety guidelines.