What to Know about Canning Lids
Streamline home canning with these three important lid tips:
- We recommend using only Ball® or Kerr® brand lids. BPA-free, these brands offer the safest, most reliable results of any lid on the market. Foods sealed with SureTight lids can be safely stored for up to 18 months.
- Use a fresh lid every time to ensure your jars seal properly, safely preserving your food. After the first use, the lid will no longer seal effectively.
- Preheating lids is not required. After extensive testing by our Quality Assurance Team, we found that it is no longer necessary to pre-warm lids before use.
These tips are valuable to remember when canning, but they just scratch the surface when it comes to canning lids! Here’s everything you need to know about canning lids:
What is a canning lid?
Our canning lids seal onto a jar for preserving fresh food. The lid is airtight and keeps food shelf stable for up to 18 months when processed correctly. Lids come in two varieties: metal-coated and plastic.
Metal-Coated Lids (one-time use only) represent the only USDA-recommended type of lid for home canning. We recommend Ball® and Kerr® brands. They’re made in the USA and are BPA-free and phthalate-free. These brands are the standard testing lid of the USDA and universities for developing home canning guidelines. Brands made in other countries may contain BPA and phthalates, which are known to buckle easily and cause frequent seal failures.
Plastic Lids (reusable) are not within USDA canning guidelines due to the solid rubber gasket, which does not vent well and lessens the vacuum seal. Plastic lids require extra caution when tightening bands on hot jars (outside of normal canning processes), are expensive for gifting and are more difficult to seal than conventional lids. Additionally, testing has shown that these lids may lose half their vacuum over the course of a year, often within the first six months.
Use Ball® Plastic Storage Caps for storing foods in the fridge or freezer.
Why don’t I have to preheat my lids?
After comprehensive testing by our Quality Assurance Team, it was determined that it is completely safe to skip pre-warming lids in the canning process. While it is still safe to simmer your lids before use, you should never boil them. Our recommendation (for over 40 years) has always been to simmer (180°F) – but not boil (212°F) – the lids.
When did this change?
In 1969, we switched our sealing gasket from a latex base to one of Plastisol. Latex requires preheating to soften the material before canning to create an effective seal. The Plastisol does not require preheating, but doing so will not damage it.
What about sterilizing the jars?
Sterilizing Ball® jars and lids is not necessary for home canning. Processing in your canner for 10 minutes or longer will sterilize the jars and lids. However, we do recommend that you pre-heat your jars to avoid thermal shock breakage that may occur as a result of drastic temperature changes while filling the jars with hot food
How should I prepare my lids now?
Removing the simmering step speeds up the time it takes to preserve your favorite fresh, local produce. Since preheating lids is not necessary, we recommend prepping lids by washing with warm, soapy water and keeping them at room temperature until you’re ready to can.
Why haven’t I heard about this before now?
We have recommended preheating lids in simmering water on product packaging and in our Ball® Blue Book Guide to Fresh Preserving in the past. Live webcasts and canning demonstrations on FreshPreserving.com have also announced the changes. While many of our customers are experienced canners who do not seek instructional updates, we recommend staying up-to-date with best practices of the USDA and those of the manufacturer. Through online resources, packaging and social media, we are trying to communicate the change with as many preservers as possible.
Will this lead to more seal failures?
Any seal failures are likely unrelated to the updates in the Ball® or Kerr® canning lids as the sealing compound has remained essentially the same since 1969. If you are experiencing seal failure, please visit our Problem Solver page to explore possible solutions.