- Eartha Kitt (via thatkindofwoman)
Making low sugar strawberry jam with Pomona’s Universal Pectin®
This post is meant to be a general overview of canning jam, not a comprehensive description of safety guidelines. Please refer to my book The Natural Canning Resource Book: A guide to home canning with locally-grown, sustainably-produced and fair-trade foods and USDA canning guidelines for details.
A couple of weeks ago I did a post on how low sugar pectins like Pomona’s Universal Pectin® can be used to jell jam, jelly and other fruit preserves with less sugar than traditional preserves. Regular fruit pectin only jells with a required amount of sugar, but low sugar pectins are designed to jell without sugar.
I also have a blog post from last fall showing how to make full sugar peach jam.
I bought three quarts of strawberries for making jam. Low sugar pectin allows you to make jam with up to 1/2 the volume of sugar as there is mashed fruit. I wanted use just a little more sugar than their directions allow for, so I modified the steps a little bit:
- Photo #2: When making jam using Pomona’s I dice the fruit into 1/4-inch (1/2-centimeter) pieces. I use a 4-cup-sized glass measuring cup to measure the volume of diced fruit. I then pour the fruit into a stainless steel pot. My favorite jam-making pot is a pot from IKEA that has quart and liter marks inside the pot so it is easy to see the volume of jam ingredients.
- Photo #6: I used evaporated cane sugar (unbleached sugar) from my cooperative buying club to sweeten the jam. After adding the diced fruit to the pot I added one cup of sugar, stirred, and let the mixture sit for about a half hour while I assembled the rest of the ingredients and equipment. The sugar dissolved into strawberry juice that was drawn out of the fruit naturally by the sugar itself (osmosis). After the sugar dissolved, there were exactly 6 cups of raw jam in the pot. I used the 6 cup number to calculate the ratio of pectin and calcium water to the jam volume; this is the change I made to the official directions to ensure proper gelling of the jam. This change does not affect the safety of the finished product.
- Photo #3: Because I opened a new package of Pomona’s Pectin, I had to make up a new jar of calcium water. Following the package directions I mixed 1/2 teaspoon of the calcium powder with 1/2 cup water in a clear glass jar with lid that seals tightly. I shook the jar to mix the contents. I added 3 teaspoons of calcium water to the jam pot. I placed the calcium water jar into my refrigerator for future use (it lasts for months).
- Photo #4: I measured out 3 more cups of sugar into a small blue ceramic bowl and added 3 teaspoons of pectin powder to the sugar. I used a whisk to thoroughly mix the sugar and pectin together. You want to make sure that no lumps of gelled pectin form in the cooking jam.
- Photo #5: Mise en place is a French term meaning “putting in place.” Professional bakers and cooks use it to refer to organizing all of the ingredients, tool and equipment for a project so that you don’t have to look for anything while cooking or baking. I always arrange everything before I start heating up the jam or other food to be canned so as to not have my attention drawn away from the task at hand.
- Photo #7: I heated the jam up to the boiling point and simmered it for a few minutes while using a hand masher to mash the fruit as it cooked lightly. Then I added the sugar-pectin mixture to the boiling jam, stirring continuously until the sugar and pectin were fully dissolved about another two minutes.
- Photo #8: I turned down the heat and ladled the jam into the jam jars, in this case half-pint (1 cup) jars using my canning funnel, leaving approximately 1/4-inch headspace to allow a strong vacuum seal to form later after the jam cooled down. I always wash and arrange more jars than I think will be necessary to hold all the food to be canned. I include a couple of jars that are 1/2 and 1/4 the size of the main jars to ensure I have someplace to put leftover amounts of food. I used a bamboo skewer to stir the contents of each filled jar to remove air bubbles. I used a tablespoon to transfer some of the leftover jam into the filled jars after the air bubble removal lowered the heights of the jam. I wipe the rims with a wet towel. I like to use a white towel so that I can see any coloration after wiping each rim. If I see color, I use a clean section of towel to re-wipe a rim. Sugar and other food particles on the rim will prevent a proper vacuum seal from forming, so cleaning off the rims is crucial to the process.
- Photo #9: After placing new lids on the jars I lightly tightened reused canning rings (canning rings can be reused until they no longer screw onto a jar properly). Then I used my jar lifter to place the jars into my canning pot, which contained preheated water just below the boiling point. At 7,000 feet elevation, it takes 15 minutes of boiling in a water bath to can jam. However, sterilizing the jars at this altitude takes 17 minutes, so rather than wasting energy to pre-sterilize the jars, I can jam for 17 minutes. Then I turn off the burner, remove the cover and let the jars sit in the cooling water for 5 minutes.
- Photo #10: I use my jar lifter to remove the jam from the pot and set the jars on a clean cloth to cool down. The lids make popping sounds when the vacuum seals form within a few seconds to minutes. All seven jars sealed properly. I put about 1/4 cup of leftover jam in a jar into the refrigerator immediately.