📖 Instructions

1. First, gently wash the rhubarb stalks under cold water. Trim off the very ends and any leaves (rhubarb leaves are poisonous, so make sure there gone!).
2. Chop the rhubarb into 1/2-inch to 1-inch pieces. Smaller pieces will break down more quickly, but larger pieces will give your jam a chunkier texture. I personally like a mix of both for that rustic, homemade feel.
3. In a large, heavy-bottomed pot or Dutch oven, combine the chopped rhubarb, granulated sugar, lemon juice, and Kahlua. The lemon juice helps with both flavor and pectin activation (pectin is what helps your jam set).
4. Stir everything together well to ensure the sugar is evenly distributed. Let the mixture sit for about 30 minutes. This allows the sugar to draw out some of the moisture from the rhubarb, creating a juicier base for the jam. I find it helps to occasionally stir it.
5. Place the pot over medium heat. Bring the mixture to a boil, stirring frequently to prevent sticking. Once boiling, reduce the heat slightly to maintain a gentle, rolling boil.
6. Continue to cook the jam, stirring occasionally, until it reaches the setting point. This can take anywhere from 20 to 45 minutes, depending on your stove and the moisture content of your rhubarb.
7. To test for setting point, place a small spoonful of jam onto a chilled plate. Return the plate to the freezer for 1 minute. Push the jam with your finger; if it wrinkles slightly, it's ready. If it's still runny, continue cooking and test again every 5 minutes.
8. Once the jam has reached its setting point, remove it from the heat. Skim off any foam that has formed on the surface using a spoon. This will give your jam a clearer, more appealing appearance.
9. If desired, stir in a pat of butter (about 1 tablespoon). This helps to reduce any remaining foam and gives the jam a smoother, glossier finish. Although, sometimes I skip this step.
10. Carefully ladle the hot jam into sterilized jars, leaving about 1/4 inch of headspace at the top. Wipe the rims of the jars clean with a damp cloth.
11. Place the sterilized lids on the jars and screw on the bands until fingertip tight. Do not over tighten, as this can prevent a proper seal.
12. Process the jars in a boiling water bath for 10 minutes. Ensure the jars are fully submerged in the boiling water, with about 1-2 inches of water covering the tops of the jars.
13. After processing, carefully remove the jars from the water bath using a jar lifter. Place them on a towel-lined surface to cool completely. As the jars cool, you should hear a popping sound, indicating that they have sealed properly.
14. Once the jars are completely cool, check the seals by pressing down on the center of each lid. If the lid doesn't flex or move, it's sealed. If a lid doesn't seal, you can reprocess it with a new lid or store the jam in the refrigerator and use it within a few weeks.
15. Label the jars with the name of the jam and the date. Store in a cool, dark place for up to 1 year. Once opened, refrigerate and use within a few weeks.
16. Spread on toast, scones, or biscuits, use as a topping for yogurt or ice cream, or serve with cheese and crackers for a sophisticated snack. Enjoy!