I'm posting this so I'll have it available whenever I need it. I figure I'm not the only one to lose the directions that come in the pectin box, so I thought I'd make it public. This makes a nice sweet/tart jam with a beautiful rich pink/red color. If you use a food processor to chop your strawberries, don't puree them, just chop them. To prepare jars--wash them in hot soapy water and rinse with warm water. To prepare flat lids, bring a small amount of water to a boil and remove from the heat. Place the lids in the boiling water and let sit until you are ready to use them. I use the inversion method to seal my jars (place them upside down for 10 minutes once the lids are on instead of canning) but that method is NOT RECOMMENDED by the USDA.
- Prepare your jars and lids for canning. This recipe makes approximately 8 cups.
- Remove the stems from the strawberries, and crush to 2 1/4 cups. You can crush with a potato masher, food processer, or my favorite way, by hand.
- Chop rhubarb (you'll need it to measure 1 3/4 cups), place in saucepan with 1/2 cup water, bring to boil and boil about 2 minutes, or until rhubarb is soft.
- In a large (6- or 8-quart) pot, combine the strawberries, drained rhubarb, sugar, and butter if using and bring to a full rolling boil over high heat.
- Add the pectin and bring back to a boil. Boil for one minute and then remove from the heat.
- Skim off any foam (if you used the butter, there may not be any foam) and pour into your prepared jars leaving 1/8 inch headspace.
- Wipe jar rims and threads, cover with two piece lids, screw bands on and boil in a canner for 10 minutes.
- Remove jars from canner and allow to sit overnight. Check the seal, if any jars did not seal, place in the fridge and use immediately. Store properly sealed jars up to one year in a cool dry place.