Canning is a time-honored tradition, a way to preserve the bounty of the garden and enjoy summer’s flavors throughout the year. But with canning comes a set of guidelines and best practices that can sometimes seem confusing. One question that frequently surfaces among both novice and experienced canners is: Can you lay jars down when canning? The short answer is a resounding no, and here’s why. Let’s delve into the science and safety behind this crucial canning rule.
Why Upright is the Only Way to Go: Understanding Canning Principles
Canning is essentially a sterilization process combined with creating a vacuum seal. This process destroys harmful microorganisms that can cause spoilage and makes the food safe to eat for an extended period. The effectiveness of this process hinges on several factors, including proper temperature, processing time, and, importantly, jar position.
When jars are processed upright in a boiling water bath or pressure canner, the heat circulates evenly around the jars, ensuring uniform sterilization of the food inside. This uniform heat distribution is vital for eliminating bacteria, yeasts, and molds. Furthermore, maintaining an upright position is critical for achieving a proper seal.
The Importance of the Headspace
Headspace refers to the empty space between the top of the food and the lid of the jar. This space is essential for creating a vacuum seal during the cooling process. When the hot food cools, it contracts, creating a vacuum that pulls the lid down tightly against the jar’s rim.
Laying jars down disrupts this process in several ways. First, it can prevent the proper venting of air from the jar during processing. As the food heats, air needs to escape to create the vacuum. When a jar is lying down, food particles can get trapped between the lid and the jar rim, interfering with the seal. This contamination creates a pathway for air and bacteria to re-enter the jar after processing, leading to spoilage.
Second, laying jars down increases the risk of food seeping out of the jar. The pressure inside the jar rises during processing, and some liquid may escape. If the jar is upright, this liquid is minimal and contained within the canner. However, if the jar is on its side, a significant amount of liquid and even some solid food can leak out, reducing the amount of food in the jar and further interfering with the seal.
The Science Behind the Seal
The sealing process depends on the specific design of canning jars and lids. The lid has a rubber-like compound around the rim designed to soften and create an airtight seal when heated during processing. When the jar cools, the lid is drawn down, creating a vacuum and permanently sealing the jar.
When a jar is horizontal, the sealing compound may not make consistent contact with the entire rim of the jar. This inconsistent contact can result in a weak or incomplete seal, increasing the risk of spoilage. A proper seal is crucial for safe and effective canning.
The Risks of Laying Jars Down: Spoilage and Health Concerns
The most significant risk of laying jars down during canning is spoilage. Spoilage can occur even if the jar appears to be sealed. Microorganisms, such as bacteria, yeasts, and molds, can still enter the jar through a weak or incomplete seal. These microorganisms can multiply and produce toxins that can cause serious illness.
One particularly dangerous type of bacteria that can grow in improperly canned food is Clostridium botulinum, which produces botulinum toxin. Botulism is a severe and potentially fatal form of food poisoning that can cause paralysis and death. Botulism is a serious concern in home canning, and following proper canning procedures is essential for preventing it.
Even if botulism doesn’t occur, spoiled food can still cause other types of food poisoning, leading to symptoms such as nausea, vomiting, diarrhea, and abdominal cramps. Protecting your health and the health of your family should be your top priority when canning.
Visual Cues of Spoilage
There are several visual cues that can indicate spoilage in canned goods. Look for the following signs:
- Bulging lids: A bulging lid indicates that gas is being produced inside the jar, which is a sign of microbial activity.
- Cloudy liquid: The liquid in the jar should be clear. If it is cloudy or discolored, it may be contaminated.
- Unusual odor: When you open the jar, check for any unusual or off-putting odors. A sour, fermented, or otherwise unpleasant smell is a sign of spoilage.
- Mold: Any visible mold growth inside the jar is a clear indication of spoilage.
If you notice any of these signs, do not consume the food. Discard the jar and its contents safely.
Best Practices for Safe Canning: Setting Yourself Up for Success
To ensure safe and successful canning, follow these best practices:
- Use proper canning equipment: Invest in a good quality boiling water bath canner or pressure canner. Make sure you have the right size jars, lids, and rings.
- Follow tested recipes: Use recipes from reliable sources, such as the USDA Complete Guide to Home Canning or university extension services. These recipes have been scientifically tested to ensure they provide adequate processing times and temperatures to kill harmful microorganisms.
- Prepare food properly: Wash and prepare food according to the recipe instructions. This may involve peeling, chopping, or blanching.
- Pack jars correctly: Fill jars to the correct headspace. Use a nonmetallic utensil to remove any air bubbles from the jar. Wipe the jar rim clean with a damp cloth before placing the lid on top.
- Process for the correct time: Follow the recipe’s recommended processing time. Adjust the processing time for your altitude, as higher altitudes require longer processing times.
- Let jars cool properly: After processing, remove the jars from the canner and let them cool completely on a towel-lined surface. Avoid touching or disturbing the jars while they are cooling.
- Check for a proper seal: After the jars have cooled, check to make sure they are properly sealed. The lid should be concave and not move when pressed down in the center.
Understanding Headspace Recommendations
Different foods require different headspace measurements. Low-acid foods, which are processed in a pressure canner, generally require a larger headspace than high-acid foods, which are processed in a boiling water bath.
Generally:
- Fruits, jams, and jellies: 1/4 inch headspace
- Pickles and relishes: 1/2 inch headspace
- Vegetables and meats (pressure canned): 1 to 1 1/4 inch headspace
Always consult your specific recipe for the recommended headspace. Proper headspace is crucial for achieving a good seal.
Choosing the Right Canning Method
The type of food you are canning determines which canning method you should use.
- Boiling water bath canning: This method is suitable for high-acid foods, such as fruits, jams, jellies, pickles, and relishes. The high acidity of these foods inhibits the growth of Clostridium botulinum.
- Pressure canning: This method is necessary for low-acid foods, such as vegetables, meats, poultry, and seafood. Pressure canning achieves higher temperatures than boiling water bath canning, which is required to kill Clostridium botulinum spores in low-acid foods.
Using the wrong canning method can result in spoilage and potentially life-threatening illness.
Debunking Myths and Addressing Common Concerns
There are several myths and misconceptions surrounding canning that can lead to unsafe practices. Let’s address some common concerns.
Myth: You can re-use old lids.
Fact: Canning lids are designed for single use only. The sealing compound is only effective for one processing cycle. Re-using lids can result in a weak or incomplete seal.
Myth: Adding aspirin to the jar helps to preserve the food.
Fact: Aspirin does not have any preserving properties and is not safe to use in canning. Follow tested recipes and proper canning procedures.
Myth: You can process jars in the oven or dishwasher.
Fact: These methods are not safe or effective for canning. They do not provide consistent heat distribution and cannot guarantee the destruction of harmful microorganisms.
Myth: If the lid pops, the jar is sealed.
Fact: While a popping sound indicates that a vacuum has been created, it does not guarantee a complete and airtight seal. Always check the seal by pressing down on the center of the lid after the jar has cooled.
Addressing Altitude Adjustments
Altitude plays a significant role in canning because water boils at a lower temperature at higher altitudes. This lower boiling point affects the processing time required to kill harmful microorganisms.
Here’s a general guideline for altitude adjustments:
- Boiling water bath canning: For altitudes above 1,000 feet, increase the processing time according to the recipe instructions.
- Pressure canning: For altitudes above 2,000 feet, increase the pressure according to the recipe instructions.
Always consult your specific recipe for altitude adjustment recommendations. Failing to adjust for altitude can result in under-processed food and spoilage.
Conclusion: Canning Safely and Enjoying the Harvest
Canning is a rewarding way to preserve food and enjoy the fruits (and vegetables!) of your labor. By following proper canning procedures and understanding the science behind it, you can ensure that your canned goods are safe, delicious, and long-lasting. Remember, laying jars down during canning is a definite no-no. Stick to upright processing, use tested recipes, and prioritize safety above all else. With a little knowledge and attention to detail, you can confidently embark on your canning adventures and reap the rewards of a well-stocked pantry.
Can I lay jars down in a water bath canner?
Laying jars down in a water bath canner is strongly discouraged. The primary reason is achieving a consistent and reliable seal. When jars are submerged upright, heat is evenly distributed around the jar, ensuring proper processing and vacuum formation. Laying jars sideways can lead to uneven heating and pressure within the jar, disrupting the sealing process.
Furthermore, improper sealing can result in spoilage and potential foodborne illnesses. The uneven pressure distribution when jars are laid down can cause food to seep between the jar and the lid, preventing a proper vacuum seal. This compromised seal allows bacteria and other microorganisms to enter the jar, contaminating the food and making it unsafe for consumption. Always prioritize upright processing for safe and effective canning.
What about laying jars down in a pressure canner?
Similarly to water bath canning, laying jars down in a pressure canner is not recommended. Pressure canners require precise operation to reach the correct temperatures and pressures necessary for safely preserving low-acid foods. Tilting or laying jars can interfere with the even distribution of heat and steam within the canner.
Uneven heating can lead to insufficient processing, especially in the center of the jar, which can result in botulism poisoning. The position of the jars can also affect the venting process, crucial for removing air from the canner before pressure builds. Laying jars down can obstruct proper venting and potentially compromise the safety of the canned goods.
Does laying jars down affect the seal quality?
Yes, laying jars down during the canning process significantly impacts the seal quality. A proper seal is essential for preventing spoilage and ensuring the long-term safety of your canned goods. The integrity of the seal relies on consistent heating and pressure applied evenly across the jar and lid.
When jars are laid on their sides, the contents may interfere with the lid’s ability to properly seal to the jar’s rim. Food particles can become trapped between the lid and the jar, preventing the creation of a tight, airtight seal. This compromised seal allows air and microorganisms to enter the jar, leading to spoilage and potential health risks.
Why do some people claim laying jars down works?
Some individuals may claim success laying jars down, often based on anecdotal experiences or outdated practices. It’s important to understand that even if a jar appears to seal when laid down, it doesn’t guarantee the food is safe. Visual inspection alone is not a reliable indicator of complete sterilization and proper sealing.
While some may have gotten away with this method in the past, food safety recommendations have evolved based on scientific research. Modern canning guidelines emphasize the importance of upright processing to ensure consistent heat penetration and proper sealing, significantly reducing the risk of spoilage and foodborne illnesses like botulism. Relying on anecdotal evidence over established safety protocols can be a dangerous gamble.
Is it okay to lay jars down after they’ve cooled and sealed?
Once the jars have cooled completely (usually 12-24 hours after processing) and you’ve confirmed that a proper seal has been achieved, it is generally safe to lay them down for storage. This is because the vacuum seal is already established and will prevent air or contaminants from entering the jar.
However, consider the food being stored. Some liquid-rich canned goods might leak if the seal is not perfectly airtight, or the contents may shift and potentially disrupt the seal over time. Therefore, it’s generally best to store jars upright, especially those containing liquids or larger chunks of food, to minimize the risk of any issues. Regularly inspect jars for any signs of leakage or spoilage, regardless of their storage position.
What if my canner is too short for my jars to stand upright?
If your canner is too short to accommodate jars standing upright, you should consider investing in a taller canner. This is the safest and most recommended solution, ensuring that jars are fully submerged and heated evenly. Using a canner that is the proper size is an essential aspect of safe home canning.
Alternatively, if purchasing a new canner is not immediately feasible, you could explore using shorter jars. Selecting jars that fit properly within your existing canner will allow you to process them upright, following established safety guidelines. Avoid improvising methods that compromise the recommended canning procedures, as this can lead to unsafe food products.
Are there any exceptions to the “no laying down” rule?
Generally, the “no laying down jars during processing” rule applies universally to all home canning situations, whether you are water bath canning or pressure canning. There are no widely accepted or scientifically-backed exceptions to this guideline. The recommendation to process jars upright is a cornerstone of safe canning practices.
While you may encounter information suggesting otherwise, it is critical to prioritize food safety above all else. Following established canning guidelines, including processing jars upright, is the best way to protect yourself and your family from foodborne illnesses. Always consult reputable sources like the USDA Complete Guide to Home Canning for the most up-to-date and reliable canning information.