One of my favorite garden bounties every year is the blackberry jam I get from my beautiful 100’ row of thornless blackberry vines. I love my blackberries for many reasons: they’re one of my few pest-free crops, they’re perennials, and they’re linked to my Swedish grandfather who was a master horticulturist and berry grower for over half a century. I also get a feeling of not only craftsmanship, but companionship with my grandpa when I’m out working with the vines: tying up this year’s growth, propagating new plants from tip runners, harvesting the berries, and cutting out the two-year stems at the end of the summer.
But the best part of all, aside from grazing fresh blackberries on the hoof, is enjoying my seedless blackberry jam.
While I’ve never outgrown Peanut Butter & Jelly sandwiches, the 30+ pints of jam I average each year mostly end up in places other than peanut butter sandwiches. I use it to flavor my home-made yogurt, it’s great on waffles and pancakes, and percentage-wise, I probably use the most to flavor my frozen lemon-cucumber-protein smoothies that get me through the hot summers without air conditioning. I share some with friends and neighbors and they’d never let me through the front gate at the family reunion without jars of jam for everyone.
I’m going to present a few radical ideas on how to max out your canning batches, as well as how to create your own jam recipe, and I can assure you they are perfectly safe to try at home. I’ll be using the example of my blackberry jam recipe which I spent five years perfecting, but the general ideas will work with any canning recipe you have. You may need to play around with your recipe to get it just right. With jam, the worse that can happen is that you’ll not end up with the exact consistency you were shooting for, in which case, there are lots of other uses for it. But that happens in any given year anyway, for reasons which I will point out. With the methods I’ll show you, you’re actually more likely to have consistent batches from year to year. So friends, preppers, and canners, lend me your ears.
No Cups, Use a Scale
The first radical idea I want to present is that you use a scale for your canning instead of cups. Weight is exact. Cups are slower and less accurate, and a “cup” varies from one manufacturer to another.
When I first learned to bake bread, I added the ingredients together exactly like the recipe called for. It was too dry. I added more water. Now it was too wet. Back and forth. Before my first loaf of bread was even in the oven I said to myself, “This is really dumb.” Now my recipe is by weight. I weigh out the flour, weigh out the water, and it turns out perfect every time. Electronic kitchen scales average around $16 (here’s Amazon’s best-seller) but you can find cheaper models. Most of you probably already own one.
Most boxes of pectin warn you against making more than one batch of jam at a time. We’re going to ignore those warnings because if we weigh the ingredients instead of using cups, and follow the other tips in this article, we can make 11 pints of jam at a time. The whole purpose of our method is to max out the number of pints we can fit in our canner for each batch. This not only allows us to save time but also energy costs. In my particular case, it also means I can make 32 pints of jam in three batches instead of six. My feet hurt just thinking about standing at the stove making six batches!
Jamology 101, Why Jam Gels
Before I go any further, let me mention a few quick basics of Jamology 101.
The main reason jams and jellies don’t need to be processed in a pressure canner is because the botulism-causing bacteria we home canners worry about cannot survive in an acidic, high-sugar environment found in most jams. Sugar not only sweetens the jam but it also absorbs water which helps in the gelling process and determines the final consistency of our jams. We add lemon or lime juice because the acid helps separate the natural pectins found in fruits so they can help the gelling process as well.
When you think of how crunchy a green peach is that’s because the cell walls are still full of pectin. As the peach ripens, the pectin breaks down, the peach softens and becomes much more pleasurable to eat. If you keep that in mind as you are picking fruit for your jams and jellies, adding in a few not-quite-ripe fruit will help the gelling process along. Using 100% dead-ripe fruit will make it harder for the added pectin alone to get the job done. If you’ve ever wondered why some years you get a good set and other years not, the ripeness of the fruit could be the biggest reason.
Creating Your Own 11-Jar Recipe
When I first started making blackberry jam, I followed the recipe from the box of pectin. It left much to be desired so I set out to create my own recipe. The standard was my grandma’s raspberry jam that I grew up with. It had real ZING! That’s what my jam needed to have if anyone was going to take me seriously as a jam-meister. The recipes I was finding lacked lemon juice so I added that for zing. You’ll notice I’m not adding powdered armadillo teeth or things that are not normally found in jam recipes so this is perfectly safe experimentation.
For sugar, I needed some guidelines to stay within for gelling purposes. Using recipes from three brands of pectin, and standardized fruit weights from KingArthurFlour.com, I was able to determine the following proportions of fruit to sugar by weight:
- MCP: 1.19 unit of fruit per unit of sugar = 46% sugar
- SureJell: 0.96 unit of fruit per unit of sugar = 51% sugar
- Hosier Hill Farms: 0.60 unit of fruit per unit of sugar = 62% sugar
Since MCP’s recipe uses only 46% sugar, I knew my own recipe could go as low as 46% and still be safe.
Pectin is high priced when bought in single-batch boxes. In addition, each brand has a different weight (1¾-2 oz), and they vary in ingredients. So, rule number one with pectin is to never mix brands in a batch of jam. And for the frugal-minded, it’s best to buy pectin in bulk. The best deal I’ve found is Hoosier Hill Farms in a 2 lb. bag which averages around 55¢/ounce, about half of what a single-batch box costs.
Skip Grandpa’s Ounces and Pounds, Use Grams
The second radical idea I want to propose is that you use grams when weighing out your ingredients instead of ounces and pounds. They’re so much easier to work with as you’ll see in a moment. I put pounds in parentheses just so you have a ballpark idea of what we’re talking about. I have the lemon juice measured out in cups since, on a full recipe, that’s the easiest way to measure it out, but the grams are needed for that partial batch.
My final recipe:
Recipe for 11 pints of Seedless Blackberry Jam
- 3,400 grams of strained blackberry puree (=7½ lbs)
- 3,000 grams of sugar (=6.61 lbs)
- ½ cup (118 grams) lemon juice
- 112 grams pectin
- 1 T butter
Again, the reason you want to use grams on your scale is that they’re so easy to work with. I don’t even think of them as grams, it’s just a target number on the scale that I am trying to hit.
I pick blackberries every other day and freeze them until the end of the harvest so I can make jam all at once. I know from experience that I’m going to get the first two 11-pint batches, but how much of the third batch will I get?
Here’s where the beauty of using grams comes in. On the third batch, I’ve strained the remaining blackberries and discover I only have 2,686 grams of blackberry puree, 714 grams short. No problem! Luckily I have a calculator handy. By dividing 2,686 by the 3,400 grams needed for a full batch, I can figure out what percentage of a batch I can make.
2,686 ÷ 3,400 = 0.79
Since I know I can only do 79% of a full batch, I simply multiply all my other numbers by 79% and my recipe is good to go.
- 3,000 grams of sugar x 0.79 = 2,370 grams
- 118 grams of lemon juice x 0.79 = 93 grams
- 112 grams of pectin x 0.79 = 89 grams
- 1 T butter
If you were to try that with pounds and ounces, it turns into a huge mess in a hurry. If you were to try that with cups…well, you just wouldn’t even try. (The butter is only to keep the foam down while you are stirring the pot so keep it at 1 T.)
The thing to keep in mind is, the units are irrelevant, they’re just numbers on a scale so it’s not important if they’re grams, grains, troy ounces, or Jorj units. They’re targets we’re trying to hit as we are pouring ingredients into a bowl. It’s just that simple. When I’m pouring the sugar, I’m not even thinking about grams, all I’m thinking as I’m watching those numbers count higher is that I have to hit 2,370 and then stop.
There are lots of reasons for learning to cook using weight instead of the traditional cups and measuring spoons. Here’s a visual example below. On the left, I gathered together the items for making a salad dressing as instructed in the recipe. On the right, making the same recipe by weighing the ingredients instead of measuring them out. Much less to clean up! You can go to KingArthurFlour.com to help convert many cooking ingredients over to grams.
Max Out Your Canner to Save Time and Energy
The reason why we’re making an 11-pint batch in the first place is because that’s how many jars the most common 21-quart, enameled, Ball water-bath canner holds. If you take the basket out, which only holds 7 pint-size jars due to raised dividers, you can get 4 more jars in. In mine, 11 Ball/Kerr jars will fit 9 around the outside and 2 in the middle. With generic jars, only 8 are going to fit around the outside and one in the middle. Now that you know how to do the jam math, it’s easy to get your particular canner out, see how many pints it will hold, and then customize your jam, pickle, salsa, or whatever recipe for that number of jars. Is math beautiful or what?
Some will warn you against having the jars sitting directly on the bottom of your canner instead of in the basket. As long as your canner has a corrugated bottom, don’t worry, I’ve never had a jar break. Those raised rings allow bubbles to escape as water boils under the jars. If the bottom of your canner has a surface flat enough to fry pancakes on, you’ll need a Plan B. Either some sort of a trivet on the bottom or you may be lucky enough to have a canner with a rack that looks like a flat, round, bread-cooling rack. You just want to avoid dividers which limit the number of jars you can fit in.
It all boils down to trying to maximize your canner space after you’ve gone to the trouble and expense to heat up all that water. It also saves time and propane since the more jars you can fit in, the less water it takes to cover the jars.
To make my 32 pints of blackberry jam using traditional one-box-of-pectin batches, would have taken six batches. Instead, I did it in three. I was pretty tired by the time it was over. There was no way I could have done six in the same day. And to do three one day, then have to clean it all up and do three more the next day, would have been a huge psychological hurdle.
I also have 11-jar recipes for my pickled three-bean salad, bread and butter pickles, and salsa. It makes my canning much more efficient and enjoyable to get the pints done in 11-jar batches. You can also apply these same rules to increase the number of jars on your quart-jar batches as well. Since so many canning recipes say “makes 5-6 pints,” a good starting point is to just double the recipe and see if you get 11 pints. As you are measuring out the ingredients, “4½ cups green beans,” weigh the 4½ cups of beans in a bowl and write that number (563 grams) in your recipe book next to “4½ cups.” Do that with each ingredient and the next time you use the recipe, it will go much more quickly using the grams you’ve written in the margin.
One last thing I do is to take photos of my setup. The example below shows me how to set up my strainer, seed catcher, puree catcher, and scale, with an index card telling me how many grams of puree I need per batch. The inset photo reminds me how far to rotate the strainer. If it’s set too tight, the seeds bind up the scroll inside and it quits working. I keep this printed sheet right in the box with my Squeezo strainer.
I hope you’ve picked up a few pointers that can make your home canning more efficient. The more efficient we get at it, the more likely we are to do more canning and to become more self-reliant in the process. If we’ve learned nothing else so far in 2020, it’s that the more we can depend on ourselves and what we can produce and grow at home, and less on national food-supply chains, the better off we’ll all be in the future.
When I finish a batch of canning, looking at all the jars sitting there on the counter after a long hard day, I feel so… empowered! My tired aching muscles bulge a little and I go to bed with a smile on my face, feeling just a little more confident that, come what may, I’m going to kick butt when TEOTWAWKI gets here. I hope your self-reliance skills make you feel the same way and inspire you to learn even more and to share that knowledge with others. And have fun canning this year!