Are you thinking about getting into canning, but worried by all the horror stories you read online?
Perhaps you’ve heard of somebody getting sick from improperly canned food. Maybe you’re intimidated by the thought of the pressure canner. Or you just are wondering what kinds of equipment you actually need to buy – and what can be reused.
Whatever the case may be, we’re here to help with our list of the top mistakes to avoid when canning. With this guide, you’ll learn what not to do (and what to do instead) so you can cast those fears aside and start canning as soon as possible.
Let’s jump in.
Top 21 Canning Mistakes to Avoid
First, know that the number one biggest canning mistake you can make is not starting to can at all! It’s an incredibly rewarding and enjoyable endeavor that will allow you to enjoy delicious fruits, vegetables, and meats whenever you might want them.
However, there is also a strict set of rules you need to follow if you want to keep yourself safe.
Here’s a guide on what you need to avoid.
1. Using the Wrong Type of Canner
There are two types of canners: boiling water canners and pressure canners. The former is used for canning high-acid foods like fruits and pickles, while the latter is essential for low-acid foods like vegetables, meats, and soups.
Boiling water canners reach 212°F, the temperature of boiling water.
For pressure canning, the canner needs to reach 240°F to ensure safety.
Using a boiling water canner for low-acid foods is a dangerous shortcut that can lead to botulism, a rare but dangerous illness caused by bacteria. Always check the acidity of your food and use the appropriate canner to stay on the safe side.
2. Creating Your Own Canning Recipe
Canning is a science, and you need to preserve foods according to tested and approved recipes. Creating your own canning recipe, no matter how delicious and adventurous it might seem, can be risky. Balancing acidity, water activity, and heat processing time to kill bacteria spores is delicate work that’s best left to professionals.
When in doubt, refer to trusted sources like the National Center for Home Food Preservation or the Ball Blue Book. These organizations and publications offer thoroughly tested recipes that support the right combination of ingredients and processes for safe canning.
3. Using Poor Quality Ingredients
Speaking of recipes, starting with poor quality or overripe produce is a recipe for disappointment. Quality in means quality out. Inspect your produce for blemishes, soft spots, or signs of spoilage before canning.
The same goes for pickling spices and other adjuncts; use fresh, high-quality ingredients to make sure the final product tastes just as good as it did the day you canned it.
4. Adding Extra Vegetables
It’s tempting to add an extra carrot or tomato to your canning recipes, but this can change the pH level and potentially the heat distribution during processing, affecting the overall safety of the product.
Stick to the specified amounts in the recipe to maintain the proper balance of acidity and other critical factors for safety and quality.
5. Using Thickeners, Including Starch or Flour
When canning soups and stews, you might be tempted to add starches like flour or cornstarch to thicken the liquid. This is a big no-no in canning, as it can create an environment that’s not conducive to even and safe heat distribution during processing.
The recommended approach is to can soups and stews without thickeners; you can add those when you’re ready to serve the food. This is not only safer but also allows for more flexibility in how you enjoy your canned goods, whether you prefer a stew thicker or soupier.
6. Using the Oven Instead of the Water Bath Canner
Oven canning is a shortcut that poses significant risks. This method might not reach the necessary high temperatures to destroy bacteria, and the low acidity of many foods preserved this way can foster the growth of harmful microorganisms.
For high-acid foods, use a water bath canner as specified in your recipe. This method allows for a slow and even heat distribution for safe preservation. When canning low-acid foods, use a pressure canner as it can reach the required high temperatures for safe preservation.
7. Not Adjusting for Altitude
Altitude affects the boiling point of water, which is crucial for canning. The higher you are above sea level, the lower the boiling point of water. If you don’t adjust your canning times and pressures for altitude, you might under-process your food, leading to unsafe or unpalatable results.
Most canning recipes provide guidelines for different altitudes. Be sure to consult these and make the necessary adjustments to ensure your canned foods are processed safely and effectively.
8. Failing to Vent Your Pressure Canner
Before bringing a pressure canner up to temperature, it needs to vent steam to remove any air pockets and ensure the chamber is filled with pure, even air. Failing to vent your pressure canner can result in uneven pressure inside, affecting the preservation of your food and potentially leaving portions uncooked or at risk of spoilage.
Follow your canner’s instructions precisely and wait to start timing your process only after venting is complete and you have a steady flow of steam.
9. Not Testing Your Pressure Canner Gauge
Pressure canners require precise pressure to reach the correct temperatures for safe canning. If your pressure gauge is off by even a few pounds, it could mean the difference between safe and unsafe canning.
Have your gauge tested for accuracy regularly, and especially if you’re experiencing inconsistent results with your canning. Accurate gauges can generally be adjusted; however, if yours cannot, it’s essential to replace it before your next canning session.
10. Forgetting to Acidify Canned Tomatoes
Tomatoes present a special case in canning due to their slightly acidic nature. To ensure the correct pH level that protects against botulism, most tomato canning recipes require the addition of lemon juice or citric acid.
It’s important to follow this step even if your tomatoes seem on the tart side. The acidity levels in fresh tomatoes can vary widely, and the added acid during canning provides a consistent level of safety and quality.
11. Cooling the Pressure Canner Under Running Water
After the processing time is complete, it’s time to cool your pressure canner. Cooling it too quickly, such as by running under tap water, can cause synthetic-filled jars to become more susceptible to breakage and can result in siphoning, where the liquid is drawn out of the jars during the cooling process.
Instead, follow the manufacturer’s instructions for how to cool the canner safely and gradually. This typically involves turning off the heat and allowing the canner to come down in temperature naturally.
12. Letting Hot Pack Recipes Cool Before Processing
Some home canners make the mistake of letting their jars cool down before putting them into the canner, especially with hot pack recipes. This can result in inadequate processing and unsafe food.
For hot pack recipes, prepare your jars and lids, pack them while hot, and immediately put them in the canner for processing. This will ensure that your food is safely preserved.
13. Using Recycled Jars Not Meant for Canning
It might seem environmentally conscious to reuse jars, but only certain jars are meant for canning.
Regular glass jars, such as those that once contained store-bought foods, may not be designed to withstand the heat and pressure involved in canning. Always use proper canning jars to ensure the safety and longevity of your canned goods.
14. Reusing Canning Lids
Lids are a one-and-done deal in canning. The sealing compound can degrade with use and heat, so reusing canning jar lids is asking for trouble. Always use new lids when canning to guarantee a proper seal and safeguard the health of your final product.
15. Using Paraffin on Jams and Jellies
The practice of using paraffin wax to seal jams and jellies is outdated and unsafe. This method doesn’t guarantee an airtight seal, which can lead to spoilage, and paraffin itself can leach into your food. Instead, use proper canning techniques with sterilized jars and new lids for a safe seal.
16. Using Fresh Lemon Juice
In some canning recipes, using bottled lemon juice is a safety measure, as it ensures a consistent level of acidity. Fresh lemon juice’s acidity can vary between lemons and won’t be as reliably acidic as its bottled counterpart.
For consistent safety and flavor, opt for bottled lemon juice in your tomato canning and other recipes that call for acidification.
17. Removing Air Bubbles With Metal Utensils
Air bubbles can affect the shelf stability of your canned goods. When removing air bubbles, always use a non-metallic bubble freer or a rubber spatula. Metal utensils can scratch the jar and weaken the glass, potentially leading to breakage during processing or on the shelf.
18. Forgetting to Measure Your Headspace
Headspace is the room between the food and the lid of the jar. For proper sealing and processing, it is essential to maintain the correct headspace as specified in your recipe. Too much headspace can result in a poor seal, while too little can lead to food splattering during processing.
Use a headspace measuring tool to ensure you get it just right. This step might seem small, but it’s important for the safety and aesthetics of your canned goods.
19. Ignoring Jar Size
Jar size isn’t just about presentation; it’s about safety and shelf stability.
Canning recipes are developed and tested for specific jar sizes, which includes consideration for heat distribution and processing time. Using different jar sizes can lead to under or over processing of your food, so always use the size specified in the recipe.
20. Overtightening the Lids
It’s a bit of a Goldilocks story: lids need to be tightened just right to allow for the safe venting of air during processing and for an appropriate seal. If lids are overtightened, they might not vent properly, or the pressure inside the jar can cause the seal to fail.
Before processing, check your jars for the recommended tightness, and make adjustments as necessary to achieve a “fingertip tight” closure.
21. Placing Hot Jars on the Counter
After processing, it’s tempting to take your hot jars out of the canner and directly onto a cold surface for immediate cooling. This is a risky move that can lead to thermal shock, cracked glass, and compromised seals.
It’s important to place them on a towel or a wooden cutting board to ensure a smoother, gradual cooling process.
Final Thoughts
Remember, canning is a science as much as it is an art, and precision and patience are key ingredients in the canning success recipe.
Understanding these 21 mistakes will not only keep your foods safe – but will also allow you to take full advantage of the preserving season with delicious results.
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