How To Can Evaporated Milk: A Safe and Simple Guide
Canning evaporated milk requires a specific process to ensure safety and prevent spoilage. You must pressure can evaporated milk for a precise length of time at the appropriate pressure, and proper preparation and technique are critical for success.
Why Can Evaporated Milk?
Evaporated milk, also known as unsweetened condensed milk, is fresh milk that has had approximately 60% of its water removed. This concentration gives it a richer flavor and creamier texture than regular milk. Canning evaporated milk offers several advantages:
- Extended Shelf Life: Home-canned evaporated milk can last for years when stored properly in a cool, dark place. This is especially beneficial in areas with limited access to refrigeration or during emergencies.
- Cost-Effectiveness: Canning can be more economical than purchasing commercially canned evaporated milk, especially if you have access to inexpensive fresh milk.
- Control Over Ingredients: You have complete control over the ingredients, avoiding any added preservatives or stabilizers found in some commercial brands.
- Reduced Waste: Canning allows you to preserve excess milk before it spoils, reducing food waste.
- Convenience: Having a supply of canned evaporated milk on hand is incredibly convenient for baking, cooking, and making beverages.
The Science Behind Canning Evaporated Milk
Canning is a method of preserving food by applying heat to destroy microorganisms that cause spoilage, and then sealing the food in an airtight container to prevent recontamination. Evaporated milk, being a low-acid food (pH above 4.6), requires pressure canning. This is because only a pressure canner can reach the high temperatures needed to kill Clostridium botulinum spores, which can cause botulism, a serious and potentially fatal illness. Water bath canning is not safe for low-acid foods like evaporated milk.
Preparing for Canning
Before you begin, gather the necessary equipment and ingredients:
- Fresh Milk: Use the highest quality fresh milk possible.
- Canning Jars: Use only approved canning jars, such as Mason or Ball jars. Ensure they are free from chips or cracks.
- Canning Lids: Use new, unused canning lids with rubber sealing compounds.
- Canning Rings (Bands): These are reusable.
- Pressure Canner: A pressure canner is essential. Ensure it is in good working condition.
- Jar Lifter: A jar lifter is designed to safely lift hot jars.
- Bubble Remover/Headspace Tool: This tool helps remove air bubbles from the jars and measure headspace.
- Large Stockpot: For scalding the milk.
- Kitchen Scale (Optional): For ensuring consistent filling.
- Clean Cloths: For wiping jar rims.
Step-by-Step Canning Process
Sterilize Jars and Prepare Lids: Wash jars in hot, soapy water and rinse thoroughly. Sterilize them by simmering them in boiling water for 10 minutes. Keep them hot until ready to fill. Heat lids in a small saucepan of simmering water (do not boil).
Scald the Milk: Pour the fresh milk into a large stockpot. Heat over medium heat, stirring constantly, until it reaches 170-180°F (77-82°C). Do not boil. This process reduces the risk of curdling during canning.
Fill Jars: Ladle the hot, scalded milk into the hot, sterilized jars, leaving 1 inch of headspace.
Remove Air Bubbles: Insert a bubble remover or other non-metallic utensil into the jar and gently press against the side to release any trapped air bubbles. Adjust the headspace if necessary.
Wipe Jar Rims: Clean the jar rims with a clean, damp cloth to remove any spills or residue. This ensures a proper seal.
Place Lids and Rings: Center a lid on each jar and screw on a ring until fingertip tight. Do not overtighten.
Load Jars into Pressure Canner: Place the jars into the pressure canner, making sure they do not touch each other. Add the amount of water specified in your pressure canner’s instructions (usually 2-3 inches).
Process in Pressure Canner: Follow your pressure canner’s instructions for venting and pressurizing. The processing time and pressure depend on your altitude and jar size.
Jar Size Processing Time (Minutes) at 10 PSI Pint (16oz) 25 Quart (32oz) 30 Cool Canner and Remove Jars: After processing, turn off the heat and allow the canner to depressurize naturally. Do not force cool it. Once the pressure is at zero, carefully remove the lid and wait 10 minutes before removing the jars.
Cool Jars and Check Seals: Place the jars on a towel-lined surface, allowing at least 1 inch of space between them. Let them cool completely, undisturbed, for 12-24 hours. As the jars cool, you should hear a popping sound as the lids seal. After 24 hours, check the seals by pressing down on the center of each lid. If the lid does not flex or give, it is sealed.
Label and Store: Label each jar with the contents and canning date. Store in a cool, dark, and dry place.
Common Mistakes to Avoid
- Insufficient Headspace: Too little headspace can cause the jars to explode during processing.
- Overtightening Rings: Overtightening can prevent air from escaping during processing, leading to seal failure.
- Improper Processing Time and Pressure: Failing to process for the correct time and pressure can result in spoilage and botulism.
- Using Damaged Jars or Lids: Using damaged jars or lids can compromise the seal and lead to spoilage.
- Forcing the Canner to Cool: Forcing the canner to cool too quickly can cause jars to break or seals to fail.
- Using Water Bath Canning: As highlighted earlier, water bath canning is never safe for evaporated milk.
Troubleshooting
- Siphoning: This occurs when liquid is lost from the jars during processing. Ensure proper headspace, avoid overfilling, and follow pressure canner instructions carefully.
- Cloudy or Discolored Milk: Slight discoloration or cloudiness can be normal. However, if the milk has an off odor or appears significantly altered, discard it.
- Seal Failure: If a jar does not seal, you can reprocess it within 24 hours using a new lid. Alternatively, you can refrigerate the milk and use it within a week.
Frequently Asked Questions (FAQs)
1. Can I use raw milk to make evaporated milk for canning?
No, it is not recommended to use raw milk for canning evaporated milk. Raw milk can contain harmful bacteria that may not be completely eliminated during the canning process, even with pressure canning. Scalding the milk beforehand helps to reduce the bacterial load and improves the safety of the canned product. Pasteurizing raw milk before canning it would be required for safety.
2. What is the shelf life of home-canned evaporated milk?
Home-canned evaporated milk, when processed and stored properly, typically has a shelf life of at least one year, and possibly longer. However, it’s best to use it within a year for optimal quality. Always check for signs of spoilage before using.
3. How do I check for signs of spoilage in canned evaporated milk?
Before opening, check for bulging lids, leaking jars, or any unusual appearance. After opening, check for an off odor, unusual color, or curdled texture. If you observe any of these signs, discard the milk immediately. Do not taste it.
4. Can I add sugar to the milk before canning?
No, it’s best to can unsweetened evaporated milk. Adding sugar can affect the heat penetration during processing and potentially compromise the safety of the canned product. You can always add sugar to the milk when you use it. Adding sugar significantly changes the process and would create a new, untested recipe.
5. My canned evaporated milk has a slightly brownish color. Is this normal?
Yes, a slight brownish color is normal and is a result of the Maillard reaction, which occurs during heating. This browning does not affect the safety or quality of the milk.
6. Can I use my Instant Pot as a pressure canner for evaporated milk?
While some Instant Pot models have a pressure canning function, it’s crucial to verify that your specific model is approved for canning by the USDA or a reputable extension service. Not all Instant Pots are suitable for pressure canning low-acid foods like evaporated milk.
7. What altitude adjustment do I need to make for pressure canning?
If you live at an altitude above 1,000 feet, you’ll need to increase the pressure in your pressure canner. Consult your canner’s manual or a reputable canning guide for the specific pressure adjustments required for your altitude. Failing to adjust for altitude can result in under-processed food.
8. Can I reuse canning lids?
No, canning lids are designed for single use only. Once a lid has been used for canning, the sealing compound is compressed and may not create a reliable seal a second time. Always use new lids for each canning batch. Rings (bands) can be reused.
9. What if I don’t have a pressure canner? Can I use a water bath canner?
Never use a water bath canner for evaporated milk. Water bath canning does not reach high enough temperatures to kill Clostridium botulinum spores, and using this method can result in botulism.
10. How can I prevent my milk from curdling during the scalding process?
Stirring the milk constantly during the scalding process helps to prevent curdling. Also, avoid overheating the milk. Aim for a temperature of 170-180°F (77-82°C).
11. Can I can non-dairy milk alternatives, like almond or soy milk?
Canning non-dairy milk alternatives requires different methods and considerations. It’s essential to follow tested recipes specifically designed for non-dairy milk. The acidity and composition of non-dairy milks can vary significantly, affecting the safety of the canned product.
12. What if I don’t use the evaporated milk within a year?
While canned evaporated milk can last longer than a year, its quality may decline over time. The color, flavor, and texture can change. If the milk shows no signs of spoilage, it is generally safe to use, but the quality may not be optimal. It’s best practice to consume the canned product within one year of the canning date.