The Short Answer
Yes, you can pressure can pork broth, but it requires following proper canning methods to ensure safety. Pork broth can be safely pressure canned provided the pH is low enough. The pH should be tested and be below 4.6. Even with proper acidity, it’s critical to use a pressure canner rather than a water bath canner. The high temperatures reached in a pressure canner kill any bacteria or pathogens, including Clostridium botulinum which causes botulism. Follow validated recipes and guidelines from trusted sources, use properly calibrated equipment, and always adhere to processing times specified for your altitude. With the right precautions, pressure canning is a safe method for preserving pork broth.
What Are the Specific Safety Concerns with Pork Broth?
Pork broth presents certain food safety challenges that must be addressed through proper canning methods. Here are the main risks:
The biggest safety concern is the risk of Clostridium botulinum bacteria which can cause botulism, a serious and potentially fatal illness. C. botulinum spores are present in soil and dust. They can contaminate any type of food and thrive in low acid, oxygen-free environments. The spores produce a toxin that causes botulism. This is why pressure canning is essential for low acid foods like meat broths. The high temperatures achieved under pressure kill the spores and prevent toxins from forming.
Other dangerous bacteria can also be present in pork, including Salmonella, Listeria monocytogenes, Staphylococcus aureus, and Escherichia coli. Proper handling, cooking, and canning techniques destroy these pathogens. However, any mistakes in the process could allow bacteria to survive.
If canning methods are inadequate, other types of bacteria can grow after canning and spoil the pork broth. Yeasts and molds can also cause spoilage. Proper acidity, heat processing, and sealing prevents spoiled broth.
Why Can’t You Use a Boiling Water Bath?
Boiling water canning is unsafe for meat broths because the temperatures reached are not high enough. A boiling water bath canner generally only heats up to 212°F, the temperature of boiling water. To destroy C. botulinum spores, temperatures of at least 240°F are needed, which is only achieved in a pressure canner. Temperatures of 250°F and above reached in a pressure canner ensure the broth is commercially sterile.
A pressure canner allows the internal temperature to rise above the boiling point of water by creating a pressurized environment. At 10 pounds of pressure, the internal temperature reaches 240°F. Higher pressures create even greater internal temperatures. 15 pounds of pressure reaches 250°F. This high heat kills C. botulinum spores that a boiling water bath would fail to eliminate.
Required for Low Acid Foods
The FDA and USDA only approve boiling water bath canning for foods with a high acid content, like fruit jams. The low pH prevents C. botulinum growth. Meat and vegetable broths do not contain enough natural acidity. The pH must be lowered with additions like vinegar or lemon juice. Even with added acid, the broth must be processed in a pressure canner to be safe.
Step-By-Step Guide to Pressure Canning Pork Broth
Follow these steps for safely pressure canning pork broth:
1. Choose a Research-Tested Recipe
Only use recipes from current, trusted sources like universities or the USDA. Do not follow old family recipes unless they have been recently reviewed for safety by a canning expert.
2. Prepare the Pork Broth
Start with a high-quality homemade or commercial pork broth. Avoid thickeners like rice, noodles, or roux mixes. Keep the ingredients simple for safe acidification and heat penetration.
3. Test and Adjust the pH
Test the pH with a calibrated meter. The pH must be 4.6 or lower to prevent botulism. If it’s higher, add vinegar or lemon juice to lower the pH. Retest to confirm it reached the safe acidity level.
4. Pour into Clean Jars and Leave Headspace
Pour hot broth into sterilized canning jars, leaving the headspace specified in the recipe, usually 1 inch. The broth should be at least 140°F when filled. Wipe jar rims with a clean, damp cloth.
5. Apply Lids and Bands
Place lids on jars then secure with bands screwed on fingertip tight. Do not overtighten.
6. Load Jars in the Pressure Canner
Place jars on the rack, not touching each other or the sides of the pot. Add 2-3 inches of hot water to the canner.
7. Vent and Pressurize the Canner
Heat on high heat until the canner vents steam. Once venting, close the vent to pressurize. Follow manufacturer instructions for pressurizing the canner.
8. Process Under Pressure
Start timing when the desired pressure is reached. Process for the full time specified in the recipe for your altitude. Do not interrupt the processing.
9. Allow the Canner to Depressurize Naturally
Turn off the heat and let the canner gradually come down to zero pressure on its own. Do not force cool the canner.
10. Remove and Check Jars
Once fully depressurized, open the canner and remove the jars with canning tongs. Check jar seals and cleanup any sticky broth.
11. Cool, Label, and Store
Cool jars at room temperature for 12-24 hours. Label with contents and processing date. Store properly in a cool, dark place for up to 1 year. Refrigerate after opening.
Choosing a Pressure Canner
It’s important to use a modern pressure canner in good working condition for safe pork broth canning. Here’s what to look for when selecting a canner:
New vs. Old Pressure Canners
If you have an antique pressure canner, it’s best to get a new one. Older models may be worn or damaged and are also harder to find replacement parts and gaskets for. Modern canners have enhanced safety features.
Size and Capacity
Choose a canner large enough to hold at least 4 quart jars standing upright for broth canning. An 8-16 quart canner is ideal for the home preserving needs of most families.
Leading brands of pressure canners include All American, Presto, and Mirro. Look for brand new canners, not used ones. Make sure any used canner has been recently inspected and serviced.
Seek canners with features like an automatic vent/cover lock, pressure regulator, safety fuse plug, and metal-to-metal sealing gasket. These offer the best safety and performance.
Manual vs. Electric
Stovetop and electric pressure canners will both work. Electric canners provide push button control but tend to cost more.
A longer warranty is preferable, showing confidence in the quality and reliability of the canner. Make sure to register the warranty with the manufacturer.
Helpful Safety Tips for Pressure Canning
In addition to carefully following the proper process, keep these safety tips in mind:
– Inspect the canner, lid gasket, and all parts before each use. Make sure everything is in good working condition.
– Only use jars specifically made for home canning. Commercial food jars and decorative jars break more easily.
– Check jar rim areas for nicks or cracks that could impact the seal. Run your finger around each rim before use.
– Use new two-piece canning lids, never reuse lids. The seals degrade over time with heat and pressure.
– Follow headspace requirements carefully. Too much or too little headspace impacts sealing and heat penetration.
– Never open the canner or release pressure manually during processing. This will ruin the established heat process times.
– If any broth escapes the jars during processing, do not open the canner. Wait until fully depressurized to remove the jars.
– Never force-cool the canner. Always allow it to depressurize naturally according to manufacturer directions.
– Check every jar seal after processing. If any haven’t sealed properly, refrigerate the broth and use within a few days or reprocess with new lids.
With the proper precautions, pressure canning is a safe preservation method for pork broth. Choosing a research-tested recipe, adding vinegar to lower the pH, and following all pressure canner directions reduces the risk of foodborne illness. Pressure canning destroys spores from dangerous bacteria like Clostridium botulinum that can’t be eliminated through boiling water processing alone. Take time to learn the proper techniques. With care and caution, you can safely can pork broth to enjoy for months to come.