Berry Jam Recipe

Prepare fruit

If using fresh berries, rinse gently and drain. Hull and quarter strawberries; leave blueberries and raspberries whole (halve large berries). If using frozen berries, thaw in a colander over a bowl so excess liquid drains, reserving the juice for later if desired.

Sterilize jars (optional)

If you plan to can the jam for shelf storage, wash jars and lids in hot soapy water, then sterilize jars by boiling them 10 minutes (keep hot until filling). Keep lids in hot water (do not boil) until ready. Alternatively, use clean jars and store in refrigerator/freezer.

Place the prepared berries (4 cups) in a wide, heavy-bottomed saucepan. Add the granulated sugar (2 cups), fresh lemon juice (2 tbsp), and lemon zest (1 tsp, if using). Stir gently to combine and let the mixture sit 10–15 minutes so the sugar begins to draw juices from the berries.

If using powdered pectin: in a small bowl whisk the pectin with 2 tbsp water until smooth and set aside.

Set the saucepan over medium heat. Stir frequently to dissolve sugar and prevent sticking. As it warms, mash some of the berries with a potato masher or the back of a spoon to reach your preferred chunkiness (for smooth jam mash more; for a chunkier jam mash less).

Increase heat to medium-high and bring the mixture to a full rolling boil (a boil that cannot be stirred down). If using pectin, whisk it in now. Continue boiling, stirring frequently and skimming any foam with a spoon. Add the pinch of kosher salt and butter (1 tsp) if using to reduce foam.

Check for set

After 8–15 minutes of boiling (time varies), test for set: place a small plate in the freezer before cooking. Spoon a small amount of jam onto the chilled plate, return to freezer 30–60 seconds, then push the edge of the jam with your finger — if it wrinkles and doesn’t flood back, it’s set. Alternatively, use a candy thermometer; jam sets at about 220°F (104°C) at sea level. If jam hasn’t set, continue boiling and test every 2–3 minutes.

When jam reaches desired set, remove pan from heat. If any foam remains, skim it off with a spoon. Let the jam sit 5 minutes to settle.

If refrigerating: ladle the hot jam into clean jars, leaving 1/4–1/2 inch headspace. Wipe rims, apply lids, and let cool to room temperature. Refrigerate up to 3–4 weeks or freeze for longer storage.

If processing for shelf stability

Fill hot sterilized jars leaving 1/4 inch headspace. Wipe rims, apply hot lids and rings finger-tight. Process in a boiling water bath: place jars in a rack in the canner, cover with at least 1–2 inches of water, bring to a boil and process pint jars 10 minutes (adjust for altitude as needed). Remove jars and cool on a towel undisturbed 12–24 hours. Check seals; store sealed jars in a cool dark place up to 1 year. Refrigerate after opening.

Yield and storage notes

This recipe makes about 3–4 8-ounce jars (approx. 3 cups) of jam depending on evaporation. Label jars with date. If jam is too loose after cooling, you can reboil and test again or refrigerate and use as a spread rather than shelf-stable jam.