Preserve the fresh taste, bright yellow and benefits of fresh corn by placing it under glass at home. Since corn is a low acid food, a pressure canner will help to avoid bacterial contamination. Follow these guidelines to put the corn under glass using either the raw method, in which the corn is quickly blanched to preserve its color, or the hot method, which involves cooking a little longer.
Ingrediants
- 9 kg of sweet corn cobs
- Salt for preserves (optional)
Steps
Method 1 of 2: Method 1 of 2: Use a pressure canner to can raw corn
Step 1. Prepare the corn
Choose fresh, ripe corn on the cob with bright green beards and puffy kernels. Peel them and remove the filaments. Wash by scrubbing the corn on the cob with a vegetable brush under cold water.
Step 2. Blanch the corn in water for 2 minutes and remove it with tongs
Transfer it to a large bowl of ice water to stop cooking.
Avoid cooking too long or you will have mushy grains
Step 3. Slice the corn on the cob using a knife, starting on one side
Stop any grains that escape using a baking tray or bowl.
- Avoid slicing the whole cob, stopping at 3/4.
- Put the bottom of the corn on a small bowl upside down to be able to slice it without losing the kernels.
Step 4. Clean 500ml glass jars and aluminum lids with warm soapy water
Keep them warm until they are ready to be filled.
Jars and lids can be kept warm by placing them upside down in a bowl of hot water or by washing them in the dishwasher and keeping them inside until needed
Step 5. Fill the ready-made jars with corn leaving about 2.5cm of space at the top
Add a teaspoon of salt to each jar (optional), then fill them with boiling water leaving 2.5cm for air.
Step 6. Wipe the rims of the jars with a clean cloth, shake them gently to let the air out and close
Place the sealed jars on the grid of the pressure canner filled with 2.8 liters of hot water.
The jars should not be in direct contact with the bottom of the canner and should not touch each other so the steam will circulate freely
Step 7. Close the canner tightly and boil the water
Let the steam escape for 10 minutes before adding the weights or closing. After 10 minutes close the valves or put the weights (it depends on the type of canner you use) and wait for the pressure to rise.
Step 8. Run the jars in the pressure canner for 55 minutes, adjusting the pressure according to the altitude (see guide)
When you get the pressure you need, aim the timer. Check the pressure gauge frequently to make sure the pressure remains constant.
- For a canner that has an electronic thermostat, put the pressure at 75.8 kPa if you stay between 0 and 610 m, 82.7 kPa for altitudes between 610 and 1220 meters, 89.6 kPa between 1220 and 1830 meters and 96.5 kPa if you are between 1830 and 2440 meters high.
- For a canner with weights, put the pressure at 68.95 kPa for altitudes between 0 and 305 meters and 103.4 kPa for altitudes above 300 meters.
Step 9. Turn off the heat and let the pressure return to 0 kPa, then remove the weights or open the valve and wait 2 minutes
Carefully remove the lid and let the steam out.
Step 10. Remove the jars with jar tongs and place them on a cutting board or thick kitchen towel to cool in a draft-free area
Place each jar 2.5-5cm of space to allow air to circulate.
Listen for the “ping” indicating that the vacuum has occurred and the air has been sucked in. The jar will be perfectly sealed after about 12 hours
Step 11. Label the jars with ingredients and date and store them in a dark, dry place
Method 2 of 2: Method 2 of 2: Use a pressure canner with cooked corn
Step 1. Prepare the corn
Choose fresh, ripe corn on the cob with bright green beards and puffy kernels. Peel them and remove the filaments. Wash by scrubbing with a vegetable brush under cold water.
Step 2. Slice the corn on the cob using a knife, starting on one side
Stop any grains that escape using a baking tray or bowl.
- Avoid slicing the whole cob, stopping at 3/4.
- Put the bottom of the corn on a small bowl upside down to be able to slice it without losing the kernels.
Step 3. Put the corn in 2 liters of boiling water for 5 minutes, stirring frequently
Avoid cooking too long or you will have mushy grains
Step 4. Clean 500ml glass jars with foil lids with warm soapy water
Keep them warm until they are ready to be filled.
Jars and lids can be kept warm by placing them upside down in a container with hot water or by washing them in the dishwasher and keeping them inside until needed
Step 5. Fill the ready-made jars with corn leaving about 2.5cm of space at the top
Add a teaspoon of salt to each jar (optional), then fill them with boiling water leaving 2.5cm for air.
Step 6. Wipe the rims of the jars with a clean cloth, shake them gently to let the air out and close
Place the sealed jars on the grid of the pressure canner filled with 2.8 liters of hot water.
The jars should not be in direct contact with the bottom of the canner and should not touch each other but the steam should be free to circulate
Step 7. Close the canner tightly and let the water boil
Let the steam escape for 10 minutes before adding the weights or closing. After 10 minutes close the valves or put the weights (it depends on the type of canner you use) and wait for the pressure to rise.
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Run the jars in the pressure canner for 55 minutes, adjusting the pressure according to the altitude (see guide). When you get the pressure you need, aim the timer. Check the pressure gauge frequently to make sure the pressure remains constant.
Can Corn Step 19
- For a canner that has an electronic thermostat, put the pressure at 75.8 kPa if you stay between 0 and 610 m, 82.7 kPa for altitudes between 610 and 1220 meters, 89.6 kPa between 1220 and 1830 meters and 96.5 kPa if you are between 1830 and 2440 meters high.
- For a canner with weights, put the pressure at 68.95 kPa for altitudes between 0 and 305 meters and 103.4 kPa for altitudes above 300 meters.
Step 8. Turn off the heat and let the pressure return to 0 kPa), then remove the weights or open the valve and wait 2 minutes
Carefully remove the lid and let the steam out.
Step 9. Remove the jars with jar tongs and place them on a cutting board or thick kitchen towel to cool
Place each jar 2.5-5cm of space to allow air to circulate.
Hear the “ping” indicating that the vacuum has occurred and the air has been sucked in. The jar will be perfectly sealed after about 12 hours
Step 10. Label the jars with ingredients and date and store them in a dark, dry place
Advice
- Freshly harvested corn is less sweet and ripe than what you would eat from a cob and tends to be more yellow and firmer during the processing process.
- Keep the gauge checked on the canner to accurately read the pressure reading.
Warnings
- To avoid the risk of Botox from bacterial contamination, which can be deadly, follow the instructions carefully.
- If the lids of the jars do not vacuum (the part in the center does not go down), use the corn immediately and do not store it.
- If the corn smells sour or foul when you open the jar, throw it away right away.
