This recipe for this raspberry jam appears in the cookbook “Foolproof Preserving.”

Store-bought raspberry jam can be a disappointment, tasting more like gummy candy than raspberries. We wanted a jam bursting with fresh fruit flavor, and we started by finding the perfect balance of fruit and sugar. For intense fruit flavor, we added a grated Granny Smith apple.

Traditionally, apple adds body to fruit jams, but in this recipe we found that it also created great bright flavor. Lemon juice boosted the brightness while also adding acidity to help the pectin set. We found that we needed to boil the jam for only 10 to 15 minutes to achieve the perfect consistency.

Slightly unripe or “just ripe” fruit will form a jam more easily than very ripe fruit, as it contains more pectin and is more acidic. For safety reasons, be sure to use bottled lemon juice, not fresh-squeezed juice, in this recipe.

Servings: 64 (Makes four 1-cup jars)Start to finish: 20 minutesChef’s Note: Do not try to make a double batch of this jam in a large pot; it will not work. Rather, make 2 single batches in separate pots.2 pounds (6½ cups) raspberries3 cups sugar1 Granny Smith apple, peeled and shredded (1 cup)1 tablespoon bottled lemon juicePlace 2 small plates in freezer to chill. Set canning rack in large pot, place four 1-cup jars in rack, and add water to cover by 1 inch. Bring to simmer over medium heat, then turn off heat and cover to keep hot.In Dutch oven, bring raspberries, sugar, apple, and lemon juice to boil over medium-high heat, stirring often. Once sugar is completely dissolved, boil mixture, stirring and adjusting heat as needed, until thickened and registers 217 F to 220 F, 10 to 15 minutes.To test consistency, place 1 teaspoon jam on chilled plate and freeze for 2 minutes. Drag your finger through jam on plate; jam has correct consistency when your finger leaves distinct trail. If jam is runny, return pot to heat and simmer 1 to 3 minutes longer before retesting. Skim any foam from surface of jam using spoon.Place dish towel flat on counter. Using jar lifter, remove jars from pot, draining water back into pot. Place jars upside down on towel and let dry for 1 minute. Using funnel and ladle, portion hot jam into hot jars, leaving 1/4 inch headspace. Slide wooden skewer along inside edge of jar and drag upward to remove air bubbles.For short-term storage: Let jam cool completely, cover, and refrigerate until jam is set, 12 to 24 hours. (Jam can be refrigerated for up to 2 months.)For long-term storage: While jars are hot, wipe rims clean, add lids, and screw on rings until fingertip-tight; do not overtighten. Return pot of water with canning rack to boil. Lower jars into water, cover, bring water back to boil, then start timer.Cooking time will depend on your altitude: Boil 10 minutes for up to 1,000 feet; 15 minutes for 1,001 to 3,000 feet; 20 minutes for 3,001 to 6,000 feet; or 25 minutes for 6,001 to 8,000 feet. Turn off heat and let jars sit in pot for 5 minutes. Remove jars from pot and let cool for 24 hours. Remove rings, check seals, and clean rims. (Sealed jars can be stored for up to 1 year.)