Canning 101: If I can do it, so can you!

I have been thinking about canning things for almost 2 years now but never actually had the guts to go through with it. From everything I read it didn’t seem that hard, yet I remained intimidated. It seemed like so many steps – boiling, sterilizing, preventing botulism, getting the right seal…yikes. The first time I attempted it was 2 springs ago when my husband and I tried to make our first batch of homemade maple syrup. We tapped a few trees, got some sap, and thought we were well on our way. I read up a little on canning but didn’t have any of the right equipment except for the mason jars. I put 7 of them in the bottom of a stainless steel cooking pot and boiled them to sterilize. Then kept them at a simmer while my husband took care of boiling down the sap. Hours later we were finally done boiling down the sap when we achieved the right temp of 219 degrees F. It turns into syrup in the snap of your fingers at this temp, avert your eyes for a moment and the whole thing can boil over and ruin. We quickly took it off the heat and I pulled out one of the seven mason jars I had simmering.  We knew it didn’t look like a lot but we hoped for the best.  The syrup filled one 8oz jar to the 2oz line. HA! 2 ounces of syrup in one mason jar. We’ve learned a few things about maple sugaring since then but this past spring when we made the syrup we didn’t actually “can” it the traditional way. We just put it in boiled and simmered mason jars and then refrigerated it.  (This year we got about 5 and 1/2 16 oz jars!) Now that strawberry season is upon us up here in CT I decided that this summer I will not be paralyzed by my canning fears. I will no longer dream about all the delicious jams and jellies I could be making.  I’m gonna do it darn it, and I’m gonna do it right!

Canning for beginners

First, why can things?  If you grow your own food, or just like to have something preserved that is healthier than store bought, then canning is a great way to do it yourself. If you do it correctly and safely the contents in the jar are shelf stable for up to a year!  Most of the recipes you can find have no harmful chemical preservatives in them and you can season the food to your liking.  It can save you money in the long run if you get a deal on produce and preserve multiple jars that you can use throughout the year.  For example I went strawberry picking at a local farm, got some awesome fresh berries, and made almost 5 8oz jars of jam.  I tweaked the recipe and used half the amount of sugar, used organic sugar, and my recipe has 4 ingredients.  I’ve looked in the store multiple times at fruit preserves and most of them had high fructose corn syrup and other ingredients that made it feel it wasn’t worth paying for.  I don’t go through a ton of jam so the 10 dollars I paid for the strawberries will last me through the year. Another tip- fresh jams and jellies also make great gifts so think ahead and you’ve got some easy holiday gifts!

Ok back to business. There are two types of canning and they both have to do with preventing botulism.  Botulism or Clostridium botulinum as it is properly called is a bacterium that produces spores that are found naturally found in our environment, mostly in the soil but can also be found in rivers, and sea waters. [source] The bacteria can grow and produce toxins (the actual thing that makes you sick)  in low acid and low oxygen environments.  Spores will not germinate in an acid environment with a pH of 4.6 or less.  When you are canning foods you are creating a great environment for this bacteria to grow- lack of oxygen is key for the toxins to form. Add in moistness, a high pH, too low temperature, too short processing time, and you’ve got the perfect place for botulism to throw a party.  Here’s where the two different types of canning come into play.

Water bath canning

Water bath canning is exactly what it sounds like, canning things in a bath of boiling water.  Water bath canning is typically a good place to start for beginners because the equipment you need is relatively inexpensive (you may even be able to use what you already have at home), it’s safer because the foods you can safely can by water bath already have a low pH (high acid level) so they are ok to process in boiling water,  and in my opinion it’s less intimidating than pressure canning.  Since the spores can’t grow and produce toxins in an acid environment it’s safe to boil.  When working with low acid foods (high pH) the jars need to be boiled above 212 degrees which means you need a pressure canner to get the temp of the water above boiling (boiling is 212 degrees F) to about 240 degrees F. In the little booklet that came with my canning pot it states

“A water bath canner’s use is limited to fruits, tomatoes, pickles, relishes, jams, jellies, and marmalades. The high acid levels in these foods make it safe to can them in boiling water, whereas most vegetables are low in acid and need to be processed in a pressure canner which produces much higher temperatures”.

Because most vegetables are low in acid they either need to be pressure canned (i.e. brought up to a super high temp to kill the spores as regular boiling will not kill spores) OR they need to be acidified (as in pickled or fermented).  Ok, so now you’re asking yourself- if my food is already acidic and boiling at 212 degrees F won’t kill spores then why do I even need to boil?  Boiling ensures extra air gets vented out of the jars and creates a vacuum seal, thus preserving the food in the jar. No boil= no seal= your food is not preserved and isn’t going to last. The seal created makes it possible for you to store your jars in a cool dry place (aka your pantry) so you don’t have to worry about refrigeration, freezing, or heavily salting as a way of preserving.  You only need a large stockpot, a rack for the jars to sit on (so the water is flowing completely around them), and some tongs to lift out the jars. Of course you need jars and lids, but you need jars and lids for both methods of canning.  I have read online that some people just put a dishtowel at the bottom of the stockpot they have at home and sit the jars on that while boiling and they come out fine.  I went to Walmart and bought a canning pot with a rack in it for 19.97 as I didn’t have a big enough stock pot and I wanted the rack and I bought a pair of jar lifter tongs for 2.97.  Case in point- it’s not going to break the bank to get started with canning.

Pressure Canning

Pressure canning is used to preserve foods that are low in acid (high pH) such as dairy, meat, seafood, soups, stews, broths, and stocks.  Because these foods are not acidic enough to prevent spore growth and toxin formation the spores must be killed by using heat.  Again, the spores cannot be killed by merely boiling because they can withstand that amount of heat. You will need to heat the jars to 240 degrees F to ensure you have killed the spores and the only way to do this is by using a pressure canner. Pressure canners are not the same as pressure cookers and it is probably not safe to attempt to can something by using a pressure cooker. You can purchase a pressure canner anywhere from around 70 bucks and up from what I have seen.  Also according to Ball’s website if you are mixing a high acid food with a low acid food you can treat it as a low acid food. [source]

Keeping things clean

When you buy jars they are not sterile. Yes they are probably somewhat clean, after all they came from a factory and haven’t been used but they came from a factory. Which means they were stored, shipped, and then sat in the store until you bought them.  To ensure safe preservation of food yes, you should sterilize the jars.  It takes at least 10 minutes of boiling to sterilize.  If the recipe you are using has a processing time of 10 minutes or more you don’t need to sterilize the jars before hand as they will become sterilized while completing the recipe.  You still need to wash them with warm soapy water first though and keep them warm before use. An easy way to do this is running them through the dishwasher and leaving the door closed until you are ready to use them.  The importance of keeping them warm is merely to prevent them from shattering in your face when you put the hot food you just prepared into a cold jar. If the recipe you are using does not take 10 minutes to process then you should boil the jars in water for 10 minutes to sterilize and of course keep them warm until you are ready to use. When I made my jam I sterilized my jars lids and bands all prior to processing and kept them in a pot of simmering water to keep warm until I was done making the jam. Then I processed it for 20 minutes.  I am a little paranoid and since I am new I just liked to have everything super clean.  Do what feels comfortable for you.  Technically you don’t even need to sterilize the lids and bands.  Another thing to note is that when you are sterilizing the entire jar must be submerged in the water. When you are processing the jars must be covered with water about 2 inches over the sealed lid to help ensure the correct seal forms.

More helpful things to know

You actually don’t have to boil the lids and bands prior to canning but you should wash them in warm soapy water so they are clean. I boiled mine because I was paranoid haha.

“Headspace” is the amount of space you leave between the food and the top of the jar to allow room for expansion during processing. For the jam most recipies call for 1/4 inch. I filled mine to just below where the threads for the bands begin.

You should always wipe the rim of the jar with a clean wet towel after putting the food in and before putting the lid on. You don’t want any food getting in the way of lid and messing up your seal.

Always process for the amount of time the recipe calls for to ensure preservation safety.

The lids may not “pop” right away after you take them out of the water bath.  You should leave the jars to cool and check the seals after 12-24 hours. There should be no flexing to the lid at all. If the lid pops and flexes you did not get a proper seal and you should not use the product.

Speaking of lids, you need fresh new lids every time you can. The bands however can be reused.

Finger tip tight means to screw the bands just to some resistance like you are tightening just slightly with your fingertips. No need to manhandle the band to get it as tight as possible on the jar. Finger tip tight allows for the air to vent, allows for expansion, and helps achieve a correct seal.

Here’s some more links with info you can check out [National Center for Home Food Preservation]  [Info from WHO on botulism]  [Great blog from Northwest Edible Life]

So now that you are highly educated 😉 on the in’s and out’s of canning, lets get started with your first recipe!


Your first recipe, strawberry jam!

It’s strawberry season so go support a local farm and pick some delicious fresh berries! Or you can get strawberries from your supermarket, either way is fine, I’m not trying to tell you how to live your life :). For this jam recipe I didn’t want something too sweet so I looked at many recipes and adjusted the sugar to what I thought would be just sweet enough.  I admit I did buy a 10 lb bag of granulated sugar while I was at Walmart getting my water bath canner. Because I’ve gone off the deep end about being natural and healthy, at the last second I changed my mind and used organic coconut sugar that I had on hand (because jam is obviously a super health food anyway lol).  But please feel free to use whatever sugar you want.  I used my kitchen aid with the paddle attachment to mash the strawberries. It went a lot faster and was super easy. It does not get them smooth by any means. I am a chunk-a-holic so this was perfect for me! The 8 cups of strawberries came out to about 4 cups mashed.  You can adjust the recipe based on how many cups of strawberries you have. The 4 cups mashed with the added apple sauce, sugar, and lemon juice filled 4 full and 1 3/4 full 8oz mason jars. On some websites I have read it says if you don’t have a full jar you don’t have to seal it you can just refrigerate it and use it right away. I put mine in the water bath and it sealed fine. I then used it the next day, and lets be real it’s already almost gone. Yum.  This recipe has less sugar than most but still produces a sweet jam with just a hint of tart. Enjoy!

Strawberry Jam

8 cups whole strawberries, hulled
2 1/2 cups sugar
1 cup unsweetened natural applesauce
2 TBSP lemon juice
5 8oz mason jars with bands and new lids

Mash the strawberries to your liking. You can puree in a food processor if you like smooth jam.
Add the applesauce and 1 TBSP of the lemon juice. Stir to combine. 
Bring the strawberry mixture to a boil in a medium to large saucepan on the stove.
When boiling add the sugar all at once and the 2nd TBSP of lemon juice. Stir constantly. Boil for about 5 minutes and remove from heat.
Fill jars with jam leaving 1/4 inch of headspace. Wipe rims clean and center lids on. Screw bands on finger tip tight. Process in water bath for 20 minutes. Take out and put on clean towel to cool. Check seals after 12-24 hours.
Enjoy your homemade jam!




      Thank you for the tip. This summer I will skip the step of sterilizing. I will have to look up an elevation chart for our new place in VT and adjust times accordingly. Thanks so much for the info and for reading!

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