Whether you tap trees and make your own maple syrup, or buy in bulk from a local source, canning maple syrup in glass jars will help it last. Learn how to hot pack maple syrup for long-term food storage.
Maple sugaring is at peak right now and we are getting a plentiful amount of sap from our trees this year. Although properly prepared maple syrup can last up to a year in the refrigerator. Bottles and jars do take up a lot of room.
The past few years, we canned maple syrup, and stored it on the shelf in our food storage area in the basement. Not only does the maple syrup last longer when canned, but is also frees up a lot of fridge space.
If you are making maple syrup, the most time consuming part is boiling down gallons of sap into syrup. The process of hot packing and canning maple syrup is just another step that will take you less than a half hour of hands on time.
- See How to Make Maple Syrup in the City to learn more
If you purchase a gallon of maple syrup in plastic jugs, you may be disappointed by the recommended use by date. Maple syrup stored in plastic lasts only up to 6 months. Since the plastic is porous, it allows oxygen in, creating a perfect environment for mold to grow. You can make it last longer by reheating and hot packing it into glass jars.
Hot Packing Maple Syrup
Maple syrup filters best while it is still hot. The high heat also kills microorganisms that can cause spoilage. Hot packing maple syrup right away into sterile containers helps prevent contamination from mold spores and yeast that are in the air.
Most commercial producers have special equipment that keeps the maple syrup at just the right temperature. However, we can hot pack maple syrup at home using mason jars. Canning jars are created to withstand higher temperatures. Don’t use regular jars for hot packing.
To hot pack maple syrup, we will sterilize the jars in a boiling water bath, fill them with hot maple syrup, and then invert the jars so the hot liquid comes in contact with the jar lid and air space to kill organisms.
The maple syrup contracts as it cools, creating a vacuum seal that will reduce the amount of oxygen in the jar, making the environment less hospitable for mold growth.
Unfortunately, mold spores are present everywhere. Mold can develop in an unopened sealed jar in spite of all these precautions. Because of their small size, spores cannot be removed entirely by filtering. Some molds can grow in high-sugar environments and may not be killed completely by heating.
We can maple syrup in half-pint jars because not only is an opened jar used up pretty quickly, but also if it turns out moldy, we can toss it away, and not lose our entire batch.
How to Can Maple Syrup
Unlike regular canning recipes, the jars of maple syrup are sealed using the heat from the boiling syrup instead of processing the jars in a canner.
Once maple sap has been boiled into the right density maple syrup, and filtered to remove sediment, it is ready for hot packing. A full and printable recipe can be found at the bottom of this article, but these are the general steps for canning maple syrup:
Step 1: Prepare your Canning Equipment
Once your maple syrup is finished, and you have completed your final filter, return it to the stove and keep it warm until you are ready to can it.
Gather your kitchen and canning equipment. You’ll need:
- Water bath canner with a canning rack
- 16 half-pint canning jars, or 8 pint sized canning jars
- Canning lids and bands (new lids for each jar, bands can be reused)
- Canning tools: lid lifter, jar lifter, canning ladle, funnel, and bubble popper
- Candy thermometer
- Plus basic kitchen supplies such as a large pot, spoon, kitchen towels, small pot, and pot holders.
Wash your canning jars, lids, bands, and canning tools, and utensils in warm, soapy water. Rinse well, and set the lids, bands, and tools aside to air dry until you are ready to use them.
Jars must be sterilized before filling with hot maple syrup to eliminate bacteria and mold spores.
Place the canning rack into the water bath canner, set the jars upright in the canner, and add water to cover the jars. Bring the canner to boil (212˚F), and then continue to boil the jars for 10 minutes at altitudes less than 1,000 feet elevation (Adjust for altitude by adding 1 additional minute for each additional 1,000 feet of elevation). Keep the jars hot until you are ready to fill them.
Lids should not be boiled, but can be warmed to soften the sealing compound to help it seal more easily. Place the lids in a small pot, fill with water, and bring to a simmer (180˚F) over low heat. Keep warm until you are ready to use them.
Step 2: Heat your maple syrup
To help eliminate microorganisms, maple syrup needs to be hot before pouring into hot sterilized canning jars.
Clip your thermometer onto the maple syrup pot, and bring it to a temperature between 180 and 190˚F oven medium-low heat. Be careful avoid heating the temperature of the syrup beyond 195˚F or it may darken, develop maple sand, and dissolve minerals that will make your syrup cloudy.
Step 3: Hot pack the jars
Lay a kitchen towel on your counter near the stove. Use the jar lifter to remove a hot jar from the canner, drain the water back into the canner, and place it on the towel. Keep the rest of the jars in the canner, so they stay hot.
Place the canning funnel on the jar, and ladle hot syrup into the jar while leaving 1/4-inch of headspace. Wipe the rim with a damp towel to remove any sticky residue.
Center a lid on the jar, place the band over the lid, and screw it on until tight. Then, immediately flip the jar upside down so the hot syrup touches all surfaces inside to sterilize the air pocket and lid. The heat will destroy microorganisms that may have been introduced while filling.
Let the jar stand upside down for 5 minutes, and then turn it upright. Loosen the band slightly, and let the jars cool undisturbed for 12 hours. Repeat with the rest of the jars, filling one jar at a time to keep everything hot.
As the jars cool, the contents in the jar contracts, pulling the self-sealing lid firmly against the jar rim to form a vacuum that will seal the jar.
Step 4: Check the seals
Space the jars apart so that air may circulate around them, and then let the jars sit undisturbed for 12 hours to cool. After the cooling period, check the seal by pushing on the center of the lid. The lid should not pop up. If the lid flexes up and down, it did not seal. Refrigerate jar and use up within a year.
Step 5: Store the jars
Label, date, and store your jars in a cool dark place. Properly canned maple syrup has a long shelf life. Use within 2 years for the best quality. Because of the high sugar content, the syrup will still good after that time period, but the color and quality may begin to diminish. Once you open the jar, refrigerate for up to a year.
How to Can Maple Syrup
- 1 gallon freshly made maple syrup
- Wash your canning jars, lids, bands, utensils, and canning tools in warm, soapy water. Rinse thoroughly, and set the lids, bands, and tools aside to air dry until you are ready to use them.
- Place the jar rack into water bath canner, set jars in the canner, fill the jars with water, and add water to cover the jar tops by about 1-inch.
- Bring the canner to boil (212˚F) over medium-high heat, and then set your timer, and continue to boil the jars for 10 minutes at altitudes less than 1,000 feet elevation (Adjust for altitude by adding 1 additional minute for each additional 1,000 feet of elevation). Keep the jars hot.
- Lids should not be boiled, but can be warmed to soften the sealing compound. Place the lids in a small pot, fill with water, and bring to a simmer (180˚F). Keep warm until you are ready to use them.
- Attach the thermometer to the maple syrup pot, and bring it to a temperature between. Be careful avoid heating beyond 195˚F or the syrup may darken and need to be filtered again to remove impurities. Maintain the temperature as you fill your jars.
- Spread a kitchen towel on the counter. Use the jar lifter to remove a jar from canner, drain, and place on the towel. Keep the remaining jars in the canner so they stay hot.
- Place the canning funnel on the jar, and use the canning ladle to fill the jar with hot maple syrup. Leave a 1/4-inch headspace at the top of the jar.
- Wipe the rim with a damp towel to remove any sticky residue that may prevent the jar from sealing.
- Center a lid on the jar, add the band, screw it on tightly, and immediately flip the jar upside down.
- Let the jar stand upside down for 5 minutes, and then turn it upright. Loosen the band slightly, and set the jar on the towel to cool. Repeat with the rest of the jars, filling one jar at a time to keep everything hot.
- Let the jars sit undisturbed for 12 hours to cool completely. After the cooling period, check the seal by pushing on the center of the lid. The lid should not pop up. If the lid flexes up and down, it did not seal. Refrigerate jar and use up within a year, or freeze the maple syrup for longer storage.
- Label, date, and store your jars in a cool, dark place and use within 2 years. Once you open the jar, refrigerate for up to a year. Discard any jars that are moldy.
This article was originally published March 23, 2019. It has been reviewed and updated with additional information.
References and Further Reading:
- Storing Maple Syrup – Michigan State University Extension
- Maple Syrup Resources – Ohio State University Extension
- Preventing Mould Growth in Maple Syrup – Ontario Ministry of Agriculture, Food and Rural Affairs