Recipe yields 5 half-pint jars.

MAKE THE PUREE

• Wash and de-stem raspberries. Cut berries in half (or quarters for really large berries).
  4 pounds fresh raspberries
• Blender puree: Place berries in the carafe of a blender along with about 1/4 cup of water. (The water will help the mixture blend more easily, but you can leave it out if you'd like.) Puree for about one minute, then scrape down the sides of the container and process for another minute. Sample and add sweetener if desired, then process for another 30 seconds or so to incorporate the sugar. If you'd like to remove seeds, run through a food mill, mesh sieve, or chinois. Add sugar to taste. Use immediately or freeze.
• For canning (canned puree must be hot packed): Combine berries and 1/2 cup water in a large pot. Cook over medium-low heat until berries are soft, stirring frequently. Mash berries in the pot, then run through a food mill, sieve, or chinois to remove seeds. Add sugar to taste. Return the puree to the cooking pot. Bring it to a boil and cook until sugar is dissolved; remove from heat.
  1/4 - 1/2 cups water, ¼ cup sugar

PREP FOR CANNING

• Fill a canning pot with water, set the lid in place, and heat on high heat until boiling. It can take awhile for the water to come to a boil, so get it started before you begin making the jam.
• Gather the jars you'll use, making sure each is clean and free of nicks in the rim, which could impede sealing. Wash jars and place empty jars into the canning pot. This keeps the jars warm and helps avoid temperature shock when pouring hot jam into the glass jars.
• Wash canning lids and rings in hot water; set aside.

CANNING STRAWBERRY PUREE

• Ladle hot puree into 1/2 pint or pint sized jars, leaving 1/4" head space. A canning funnel makes this step easy.
• Remove air bubbles and wipe jar rims to remove any fruit mixture that may have spilled. A clean rim is essential to a good seal.
• Place lids centered on the jar rim. Screw bands on finger tight.
• Use a jar grabber to gently submerge jars into hot water in the canning pot. Water should cover the top of the jars by an inch. The water will cool somewhat in reaction to the addition of the jars. Return the water to a simmer and then set the timer.
• Process for 15 minutes 0-1,000 feet altitude; 20 minutes 1,001-6,000 feet; 25 minutes above 6000 feet.
• Turn off heat and allow jars to sit in the canner for 5 minutes, then remove jars from water using the jar lifter. Transfer to a solid, towel-covered surface. Allow to cool for 24 hours.
• Check seals. Lids should be solid and pulled down tight. (if they flex and pop, the jar didn’t seal; put unsealed jars in the refrigerator and use those first).
• Remove rings and wash outsides of jars. Store in a cool dark place.