Wednesday, August 16, 2017

Freezing Sweet Corn

Today I assisted Mrs ERJ in freezing sweet corn.

I ran the blanching operation.  The purpose of blanching is to use heat to deactivate the enzymes that would otherwise continue the ripening and spoilage processes of the vegetable you are freezing.

Mrs ERJ put it into quart, freezer bags with other secret ingredients.  The critical secret ingredient is enough water to eliminate air spaces where freezer burn can happen.  Adding water also eliminates air pockets which slow cooling.

Step one:  Wait for the corn to finish blanching.  Five minutes minimum.  The blanched ears go into the kettle of cold water. The starting operation for an industrial process defines the "loafing point".  The loafing point where the operator should be if/when they finish early.  It is good practice to put the loafing point at the bottleneck operation so it always gets "serviced" as soon as it becomes available.

Step two:  When the boiling kettle is empty, move six ears of corn into it taking care to not splash sensitive body parts.

Step three:  Prepare six more ears of corn.  Cut the silk and stem ends off.  Remove husks and silk.  Place ends, husks and silk into yellow tub in upper left corner of photo.

Step four:  The ears of corn that have been cooling in the cooling kettle are now cool enough to process.  Remove ears one at a time.

Step five:  Cut kernels off of ears using knife.  Take your time.  You have lots of corn but only ten fingers.  Throw cobs into yellow tub in upper left corner of photo.

Step six:  When cooling kettle is empty of corn, dump kettle and refill with cold water from hose.  Cold water is cheap.  Electricity for freezers is not.  Return to step one.
General notes.  Turkey fryers are great for semi-production canning.  They can really pump out the BTUs.
If you need to top off the water in the boiling kettle, using the water from the cooling kettle AFTER you pull out the ears will save heating time.

I was able to blanch and remove the kernels from 65 ears of corn in 105 minutes.  That 105 minutes does not include the time to bring the boiling kettle up to heat at the start of the cycle.  We netted 14 quarts of sweet corn kernels from the 65 ears.

Between five and ten minutes could have been saved if I added about a cup of water with each cycle of six ears.  I don't know if it was evaporating or if the cobs were soaking up the water.  I had to add water mid cycle and wait for it to come back up to heat.

Another five or ten minutes could have been saved if I had a more efficient way to cut the kernels off the cob.  I had a fancy gizmo but it was not up to the task, so I reverted back to the knife.

The final "easy" thing that would increase throughput would be to crank up the burner. Given the other inefficiencies in the system, things were fairly well synchronized; until I had to add water or if the ears were exceptionally large.

A minor improvement would be to have cold water "peeing" into the cooling kettle.  It would not be difficult to crack the valve on the hose and figure out an arrangement to hold the dribble over the cooling kettle.

Sticking all the numbers together, it would not be a great trick to process an ear every 90 seconds.

1 comment:

  1. Stopped blanching corn years ago. I just freeze the ears whole - shucks and all. Pull 'em out of the freezer and thaw in the fridge(or not) and pop into the oven(still in the shucks), heat to 350F, cook for 35 min or so... great corn!