We're canning, you're canning, just about everyone is canning these days. And we think that's pretty fantastic. But before you fill your kitchen with steaming hot glass jars and pounds of tomatoes, we have a few insider tips that might just make your next canning session go a lot more smoothly.

A few weeks ago, I had the extremely happy privilege of attending one of Marisa McClellan's canning classes during the tour for her recently released book Food in Jars. (We featured Marisa here on The Kitchn during June with a series of guest posts on small batch canning.) She shared several canning tips during this two-hour class that I'd never heard before and cleared up a few mysteries. Let me tell you, there's nothing like learning from an expert!

1. Fill Jars with the Rings On - ...But, obviously, with the lids off, as in the top image. This keeps the rims clean while you're filling the jars and saves you the hassle of wiping them down later.
2. Use a Measuring Cup when Filling Jars - This just makes the whole process go more quickly and smoothly. If you're filling pint jars and using a 1-cup scoop, you know that two scoops will fill the jar. Easy-peasy. It takes away the guesswork.
3. Screw Lids Down "Fingertip Tight" - Screw the lids down just until you start to feel resistance when you tighten, aka "fingertip tight." Inevitably, some air bubbles get trapped inside the jars while you're filling them. If the lids are screwed down too tightly, those air bubbles don't have a way to escape during the hot water bath and can cause your lids to buckle. Leaving the rings and lids a little loose lets that oxygen escape without incident; the lids will form their seal as the jars cool.
4. Remove Rings Once Jars Have Sealed - Amazingly, you don't need the rings once the jars have sealed. The lids are so firmly sealed around the rim of the jar that you can literally lift them onto the air by the lid alone! Removing the unnecessary rings frees them up for other canning projects, avoids problems with the rings rusting during storage, and allows you to spot potential problems sooner — if the canned good is starting to ferment and create gas, the lids will pop right off.
5. The Bounce Test for Gauging Pectin - It's hard to know how much pectin a fruit contains, and therefore, how much you might need to add to get a jam to set properly. Here's where the bounce test comes in. Fruits that are high in natural pectin will have a more rigid cell structure and tend to bounce when you drop them onto a table, like blueberries and blackberries. Fruits that are lower in pectin tend to smoosh, like strawberries.
6. Label Jars with the Batch Number - Not only does this help keep your pantry organized, but if there's a problem — or unexpected success! — with one jar, you know which other jars you need to check. This is especially important if you're making multiple batches of the same fruit or vegetable over the course of the summer.
Are you canning this summer? What tips and tricks have you picked up from your canning experiences?

More Food In Jars
• Small-Batch Canning Recipes from Marisa McClellan on The Kitchn
• Visit Food in Jars, Marisa's blog
• Find Food in Jars: Preserving in Small Batches Year-Round, Marisa' new book, at your local library, independent bookstore, or on Amazon.com
Related: How to Make Your Own Canning Equipment
(Images: Emma Christensen)
Straw Mat from The ...

i'm hoping to do a little canning later this summer - food in jars is on my list of to-buys!
Thanks for the great tips! I started making & canning jams last year, and now I'm hooked. FYI--the new Williams-Sonoma catalog just came out with some GORGEOUS canning products, from jars (mostly for refrigerator canning, though) to labels. I'm drooling!
Well, I can a lot and I don't think I would want to put on jar rings twice - wiping the rims is quick and easy. Your jar funnel usually keeps the rim pretty clean anyway. Why the extra work?
I use a 1/2 cup ladle to fill jars - I know how much is in it - and it has a long handle to keep me away from anything hot. You have to have a pretty long-handled measuring cup to make that work.
Simply putting the date and product on the lid with a marker keeps you straight on which batch you made, and you know when you made it too.
I'm not sure I understand, putting rings on twice is a lot more work than wiping rims. Also wouldn't you have to clean the ring in addition to taking it off and putting it on? Maybe most of it comes out when you process.
I use a ladle, too, much easier on my wrist/more comfortable with the repetitive motion of filling jars than a measuring cup.
Great tips!
@sueiowa - I put the date on my canning projects, but also the batch number; I tend to make multiple batches in one day, and it's nice to know what to expect from jars in the same batch.
While some of these tips are great, I was a bit surprised that nowhere in this article was acidity mentioned. Many people are unaware that it is quite unsafe to can low-acid products (like most vegetables and anything containing meat) in a hot-water bath. Because of this I'm concerned about the picture that is used as the display; green beans would only be safe to can in a hot water bath with a great deal of added acid, like vinegar. I know that the picture was probably chosen because it is beautiful (and it really is!), but I worry that some people might not know this important information and take the picture as advice to try canning green beans or similar products in a hot water bath. Only a pressure canner is appropriate for canning low-acid foods. Hope this isn't taken negatively; I'm just concerned for people's safety!
I have similar concerns as KCSINSI regarding the picture of green beans in a canning jar in a post about water-bath canning. It isn't safe at all. And I also agree that putting on the rings to keep the rims clean is more work than simply wiping the jar rims if there is a spill. I'd end up wiping off the rings, too, or risk getting goo everywhere as I removed the ring, placed the lid, and replaced the ring.
Green beans can safely be pickled in a hot water bath. I think that is what the picture is and they are awesome!