How to Make Canned Corn at Home: A Step-by-Step Guide
Making canned corn at home involves a relatively simple process of blanching, packing, and processing the corn in sterilized jars to ensure long-term preservation. In essence, you will be freezing the growth of spoilage microbes with heat in a sealed jar.
The Allure of Homemade Canned Corn
Canning corn at home offers several compelling advantages over store-bought varieties. The most significant benefit is control over the ingredients. You can choose organic, locally grown corn, avoid artificial preservatives, and customize the salt content to your liking. This also allows you to relish the fresh taste of the harvest all year long.
Choosing the Right Corn
The key to delicious canned corn is starting with high-quality, freshly picked ears. Look for corn with plump, unblemished kernels and vibrant green husks. The silk should be moist and plentiful. It is best to can corn as soon as possible after harvesting or purchasing it.
Essential Canning Equipment
Before you begin, ensure you have all the necessary equipment:
- Pressure Canner: A pressure canner is essential for safely canning corn. Water bath canning is not recommended because corn is a low-acid food, and a pressure canner achieves the high temperatures necessary to destroy botulism spores.
- Canning Jars: Choose canning-specific jars like Mason or Ball jars. Inspect for any cracks or chips.
- Lids and Rings: Use new, unused lids for each canning batch. The rings can be reused, but ensure they are clean and rust-free.
- Jar Lifter: A jar lifter allows you to safely lift hot jars from the canner.
- Wide-Mouth Funnel: A wide-mouth funnel simplifies the process of filling jars without spillage.
- Bubble Remover/Headspace Tool: Used to remove air bubbles from the filled jars and measure the headspace.
Step-by-Step Canning Process
Follow these steps carefully to safely and successfully can your corn:
- Preparation: Sterilize your canning jars, lids, and rings by washing them in hot, soapy water and then boiling them in a large pot for 10 minutes.
- Shucking and Silking: Remove the husks and silk from the corn cobs. Rinse the cobs thoroughly.
- Blanching: Blanch the corn by boiling the cobs in water for 3 minutes. This stops enzymatic action that can affect flavor and texture.
- Cutting the Kernels: Cut the kernels from the cobs. There are specialized corn kernel removers, but a sharp knife works well. Run the knife down the cob, removing the kernels.
- Packing the Jars: Pack the corn kernels loosely into the sterilized jars, leaving 1 inch of headspace (the space between the top of the corn and the jar lid).
- Adding Liquid: Add boiling water to the jars, ensuring the corn is covered. Maintain the 1 inch headspace.
- Removing Air Bubbles: Use a bubble remover or non-metallic utensil to gently release any trapped air bubbles in the jars.
- Wiping the Rims: Clean the rims of the jars with a damp cloth to ensure a good seal.
- Lidding and Ringing: Place the lids on the jars and screw on the rings finger-tight. Do not overtighten, as this can prevent proper venting.
- Processing in the Pressure Canner: Follow the manufacturer’s instructions for your specific pressure canner. Typically, pint jars are processed for 55 minutes at 11 pounds of pressure, and quart jars are processed for 85 minutes at 11 pounds of pressure (adjust pressure according to your altitude).
- Cooling and Sealing: Turn off the heat and let the canner depressurize naturally. Do not force the process by opening the vent. Once the canner is completely depressurized, carefully remove the jars with a jar lifter and place them on a towel-lined surface to cool.
- Checking the Seal: After 12-24 hours, check the seals by pressing down on the center of each lid. If the lid flexes, it is not properly sealed and should be refrigerated and used within a week, or reprocessed with a new lid. Properly sealed jars will have a slight concave depression in the lid.
- Storage: Store sealed jars in a cool, dark, and dry place for up to a year.
Altitude Adjustments
Altitude affects the boiling point of water, and therefore the pressure required for safe canning. If you live at a high altitude, you will need to increase the pressure in your canner according to the following table:
| Altitude (feet) | Pressure (PSI) |
|---|---|
| 0-1,000 | 11 |
| 1,001-2,000 | 12 |
| 2,001-4,000 | 13 |
| 4,001-6,000 | 14 |
| 6,001-8,000 | 15 |
| 8,001-10,000 | 16 |
Common Mistakes to Avoid
- Insufficient Processing Time: Not processing the corn for the recommended time and pressure can lead to spoilage and botulism.
- Improper Headspace: Leaving too little or too much headspace can prevent a proper seal.
- Using Damaged Jars or Lids: Cracked jars or damaged lids will not create a proper seal.
- Over-Packing the Jars: Overpacking the jars can prevent proper heat penetration.
- Failure to Adjust for Altitude: Not adjusting the pressure for your altitude can result in under-processed corn.
Frequently Asked Questions (FAQs)
Is it safe to can creamed corn?
While possible, canning creamed corn is significantly riskier than canning whole kernel corn. The added thickness reduces heat penetration, making it more challenging to eliminate botulism spores. If you choose to can creamed corn, ensure you follow a tested recipe from a reliable source, such as the USDA or a university extension service, and strictly adhere to the processing times and pressures.
Can I add other vegetables to my canned corn?
Adding other low-acid vegetables, such as beans or peppers, to your canned corn can affect the pH levels and require adjustments to the processing time and pressure. Again, it is crucial to follow a tested recipe from a reputable source to ensure safety. Avoid experimenting with untested combinations.
Why is pressure canning required for corn?
Corn is a low-acid food, meaning it has a pH above 4.6. Botulism spores thrive in low-acid environments. A pressure canner reaches temperatures above the boiling point of water (212°F), which is necessary to kill botulism spores. Water bath canning does not reach these high temperatures and is unsafe for canning corn.
How long does homemade canned corn last?
Properly canned and stored corn can last for up to a year. However, it is best to use it within 18 months for optimal quality. Always inspect the jars before use. Discard any jars with bulging lids, leaks, or off odors.
What does “finger-tight” mean when tightening the rings?
“Finger-tight” means tightening the ring until you feel resistance, but not forcing it further. Overtightening the rings can prevent air from escaping during processing, leading to a poor seal or even jar breakage.
Can I reuse canning lids?
No, canning lids are designed for single use. The sealing compound on the lid is compressed during processing and will not reseal properly if reused. Reusing lids can lead to spoilage and is not recommended.
What if I don’t have a pressure canner?
If you don’t have a pressure canner, you should not can corn at home. Freezing is a safer alternative for preserving corn if you don’t own a pressure canner.
How do I know if my canned corn has spoiled?
Look for signs of spoilage, such as bulging lids, leaks, unusual odors, or cloudy liquid. If any of these signs are present, do not consume the corn. Discard it safely.
Can I use frozen corn for canning?
While technically possible, using frozen corn is not recommended. Fresh corn will result in a better texture and flavor. Freezing and thawing corn can break down the cell structure, resulting in a mushier final product.
What kind of salt should I use?
Use canning salt or pickling salt. These salts are pure sodium chloride and do not contain additives, such as iodine, that can discolor the corn or affect the flavor. Table salt can be used as a last resort, but it may result in a less desirable product.
What is the difference between a water bath canner and a pressure canner?
A water bath canner is used for high-acid foods, such as jams, jellies, and pickles. It uses boiling water to create a vacuum seal. A pressure canner uses steam under pressure to reach higher temperatures, necessary for low-acid foods like corn. They are not interchangeable for all foods.
How do I adjust the processing time if I am using different size jars?
The processing times listed are specific to pint and quart jars. If you are using other jar sizes, you should consult a reputable canning resource, such as the USDA Complete Guide to Home Canning, for accurate processing times. Using incorrect processing times can compromise the safety of your canned corn.