Pressure Canning Corn

I home canned corn for the first time in 2014.  Prior to that, we had always frozen our corn for home storage.  While this is a great way to preserve corn, in the summer of 2013, we had a freezer go out, and did not discover it quickly enough to save anything.  We lost all our corn, blackberries, blue berries, strawberries, gooseberries, and other fruits and berries.  This hit hard.  While we would survive the coming year just fine, thinking about all the work that went into growing and freezing all that food was heart sickening.  I began to think about other ways to store food that was not dependent on having freezer space.  I began to can more fruit, began making pie fillings, canned my first chicken and canned corn for the first time.  It was delicious!  While I still freeze some corn still on the cob, I will never go back to freezing the yearly supply of corn instead of canning it.

This year our corn in the garden did not germinate well, and did not look like it was going to make enough for the coming year, so we bought some from a local sweet corn patch.  On canning day, we started out early in the morning to avoid the heat, but ended up needing to avoid a summer storm.  Papa set up the fish cooker in the barn, as the rain first threatened, then began in earnest.

Blanching is the first step

We learned a few years ago, that blanching the corn in the husks allow the silks to slip and make cleaning the ears much easier.  We do this part of the job outside, keeping the mess and the heat out of the canning kitchen until processing starts.  We use our propane fish cooker.  It is filled with water and brought to a rolling boil. The ears of corn are added a few at a time and allowed to blanch for 3-4 minutes.  They are then taken from the boiling water with long handled tongs and placed into a cooler of ice cold water.  After cutting off the stem end of the ear, the husks can be grasped and the ear squeezed out with few silks remaining.  The other end is then cut off, if needed.  I then move them to the sink in the canning kitchen with ice water to continue cooling.  I use the reusable ice packs to keep the water cold.  They last through this several dozen ears and can be re-frozen after use.  Not a huge cost savings, but every little bit helps.  As soon as the corn is cool enough to easily handle, it is cut off the cob.

Remove the Kernels from the Cob

Over the years we have used various ways to cut the corn off the cob.  From a sharp knife to various styles of corn cutters, we have use all with some success, but our favorite way is with an electric knife.  This year I used our electric fish filet knife and will probably stick with this from now on.  The knife cuts clean, is not as much work (no hand cramps during the process), and leaves very little if any waste on the cobs.  After laying a cutting board across a large bowl, I went to work cutting the corn from the cobs.  In a very short time, I had a nice bowl full of corn waiting to be placed into jars.

Pack the Jars

We do most of our corn in pints since there are just two of us for most meals.  Whether you choose to can in pints or quarts, when filling the jars, you want to just gently pack.  If you over pack, you will create too much pressure during the canning process and lose most of the liquid in the jars.  This can also create a higher risk of a faulty seal.  Fill the jars with a jar funnel and measuring cup for the fastest filling.  After filling the jars, gently use the handle of a rubber spatula or wooden spoon and poke down the corn slightly.  Another method, which I use for my canning, is to firmly smack the bottom of the jar on the palm of your hand several times.  This requires no extra tools, and you almost completely eliminate the risk of over packing.  Either way will cause the corn to be gently packed into the jar, allowing the correct amount of corn to water to be in each jar for the best product after processing.  After the jars are full, add 1/2 tsp salt for pints, and 1 tsp salt per quart.  You may also add pepper or other spices, but since I use my corn for many recipes other than just heating and eating, I stick to just salt.  Finally, top the jar with water to 1″ head space.  Leaving enough head space important to prevent too much pressure building up and preventing a safe seal.  For more information, see the post “Head Space…”  Prior to placing the lids on the jars, be sure to wipe the rim clean.  Any debris that is trapped under the edge of the ring will prevent a seal from occurring.  Place flats on jars, then add rings hand tightened and place jars in canner.

Process in the Pressure Canner

The most time consuming part of the processing is the actual pressure canning.  Because the corn is low acid, high starch food, the processing time is long in comparison to other foods.  Pints and quarts are both processed at either 10 or 15 pounds of pressure, depending on your altitude.  Pints are processed for 55 minutes and quarts for 85 minutes.  Place jars on bottom rack of canner in the amount of water recommended by the canner manufacturer.  (I do add about 1/3 again the amount due to the long processing times with no ill effects–you do not want it to boil dry during processing.  This could damage the canner and also prevent the pressure from remaining at the recommended safe level.)  If you are using a large double layer canner than can hold two layers of jars, add a second rack and place the second layer of jars on this rack  Place the lid on the canner according to instructions.  Vent steam out the vent for 10 minutes, then place weight at appropriate position.  When weight begins to jiggle, set your timer for the appropriate amount of time.  Watch closely and adjust temperature under canner so that the weight jiggles a minimum of 3-4 times per minute, but make sure it is not a constant hissing.  This could indicate that too much pressure is building up and the weight can not let enough out to keep it at the appropriate level.  When the timer goes off, remove the canner from the heat and allow to cool naturally.  Venting the pressure will allow it to escape too quickly and result in the liquid boiling out of the jars and can cause the jars to not seal or even break in the canner.  Generally 15-30 minutes is enough time for the pressure to come down.  A canner with a gauge will read 0 once again, and 0n canner without the gauge, gently bump the weight to see if air rushes out.  When it the pressure is off, remove the weight, wait a couple of minutes and remove the lid.  Be careful when removing, steam will come out of the canner, and the lid will be very hot.  Use appropriate pot holders and pay attention.  Jars can now be lifted with a jar lifter and placed on a board or towel to complete the cooling process.  You are likely to see bubbles rising to the top of the liquid.  This is a good indication that the vacuum is being formed and you will get a sealed jar.  If you do not see bubble, don’t despair.  I’ve many jars seal, that I did not see bubbles rising inside the jar.

You may notice a white film on some of the processed jars in the pictures above.  That is simple mineral deposits from our well water that buildings during the high heat process.  When the jars are cool and you have removed the rings, you will want to wipe down the jars before storing them.  I have found that a rag with a bit of vinegar does a great job of removing any food debris/sticky liquids that may have found their way to the outside of the jars, and will also remove this white film.  As you can see, though we use a traditional method of preserving our corn, we utilize many modern conveniences to get the job done.  This helps to speed the process, which is a necessity with my job schedule and the many tasks that need to be done on the homestead during the time to harvest corn.

I hope that you will give pressure canning a try when you get the chance.  We absolutely love the way the corn come out and will continue to can it as long as we possibly can.  Just one of the many ways we provide for ourselves and our family here at the Modern Missouri Pioneers.