This year, I planted two paste tomato plants for the express purpose of preserving their bounty. Tomatoes are the most popular food to can at home, and it’s easy to see why. A can of tomatoes in your pantry can easily become everything from pasta sauce to minestrone soup to Mexican rice or shakshuka. There is a wealth of safe, tested recipes for tomatoes, as well as for products in which tomatoes are a key ingredient, such as salsa. In addition, any tomato variety or combination of varieties can be used, although paste tomatoes (San Marzano, Roma, Amish Paste, etc.), which have less water than slicing tomatoes, are a traditional choice.
The science of canning tomatoes has changed over time. Before 1994, it was thought that all tomatoes naturally had enough acid to be safely processed in a boiling water canner without the need for other safety measures. But research found that differences in growing conditions and variety resulted in some tomatoes not being acidic enough to inhibit microorganisms that cause illness and spoilage. Safe recipes now include the addition of acid to ensure the safety of the final product.
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Safe recipes are those that have been scientifically tested to ensure that dangerous bacteria, mold, and botulism spores are killed or inhibited in the preservation process. These can be found on university websites, on jar manufacturers’ websites, and in books such as those published by Ball. The recipes must be followed precisely. Details such as removing skins or keeping them on, chopping to a specific size, or leaving a particular amount of headspace may seem overly fussy. However, deviations from the recipe can lead to heat not penetrating the jar thoroughly, compromised seals due to siphoning, and other issues that will render your tomatoes unsafe.
If you’re new to using a boiling water canner, this is my favorite prep checklist to follow because it has helpful pictures and suggestions for equipment swaps. If you don’t have all the equipment you need, there are some cost-effective options for borrowing or purchasing. The McMinnville Public Library has a boiling water canner kit that can be borrowed using your Newberg library card; you may also have friends or neighbors who could loan you equipment. Garage sales, thrift stores, and online marketplaces are good sources for purchasing used equipment, as long as the equipment is in good condition. Most canning lids are not reusable, so be sure you have new, unexpired lids on hand before you get started.
I used the Crushed Tomatoes recipe from the Oregon State University Extension Service publication Canning Tomatoes and Tomato Products. Because I’m using tomatoes from my garden, I freeze my ripe tomatoes until I have enough to do a batch. Freezing also makes it easy to slip the skins off without having to use the blanching method. If you are using frozen tomatoes, be sure to save all the liquid that comes off during defrosting and use it as part of your recipe. Not all tomato recipes can use frozen tomatoes; some require fresh. If you are going to use frozen tomatoes, be sure your recipe allows for that.
While most of my tomatoes will be used for canning, I also used my dehydrator for tomatoes. I will dehydrate the skins that I remove during the canning process and blend them into a tomato powder that can be added to sauces and soups. I also smoked vine-ripened tomatoes for an hour and dehydrated them to create small, flavorful morsels that will enhance winter chili recipes.
