Summer is in full swing, and you know what that means? Wonderful, ripe summer fruit! And you know what THAT means? JAM! Lots of jam, and homemade jam at that. While making and preserving jam is a science that people spend years mastering, there is a way to make it at home that is relatively no-mess, no-fuss and perfect for a first-time jam maker. Just keep in mind that I am not certified in canning and preservation, so while this method works for me and has equipped me with jam that is storable for up to six months, it is really only suitable for at-home jam making. And note it is always best to reference the USDA and canning experts before embarking on food preservation on a larger scale. But really, jam-making is nothing to be afraid of! Once you start the process, it’s quite simple. And soon you’ll be off on a long a beautiful jam-making journey. Peach Saffron jam is only the beginning!

How I learned to make jam

I learned how to make jam from Abra Berens’ book, “Pulp.” While that book gave a nice overarching breakdown of how to make different fruit jams, it was very top-line, and really only gave ratios of sugar to fruit to reference. A lot more goes into jam making and canning, but it was a great starting off point. In her book, Berens says she uses a 60/40 ratio of fruit to jam. To me, it’s easier to interpret that as 3:2, or: use 2/3 the amount of sugar as you have of the amount of fruit. For example, if you are making 3 pounds of berries into jam, you’d want 2 pounds of sugar.

After making many batches of jam myself, I found I much prefer a ratio of 3:1 fruit-to-sugar when I am making jam. Fruit is already so sweet, so an excess of sugar never felt necessary.

When it comes to canning jam, I referenced the New York Times as my first foray into canning. From there I continued to learn on this subreddit, which does a great job at answering questions by directing you to different academic and professional resources. Again, I’m canning in order to share jars with my friends and keep jam in my home, so I’m comfortable using these resources at an at-home level, and they have always yielded great results.

What is pectin and how does it work?

Making jam is only possible because of pectin. Pectin is a naturally occurring soluble fiber found in most fruits and vegetables. It’s a thread-like carbohydrate, and when it is heated up, it begins to activate. As the pectin interacts with both heat and sugar it begins to thicken and suspend the fruit pieces, creating what we know as jam. It is very hard for pectin to set without sugar, which is why you see such high amounts being used in jams and jellies. You can opt for less sugar, but your fruit will not set as well, and you won’t achieve the ideal jam consistency.

Different fruits contain different levels of pectin, and this is why you see so many store-bought jams tend to use commercial pectin as an ingredient along with the fruit itself. The luxury of at-home jam making is we can skip that and rely on transforming low-pectin fruit by adding more sugar in the mix.

Here is a list of low-pectin and high-pectin fruits. For low-pectin fruits, I still hold to using a 3:1 ratio of fruit-to-sugar, just note the fruit will make a glossier jam, not a fully set one, like its high-pectin counterparts.

Low Pectin Fruit:

Strawberries

Cherries

Stone Fruit (peaches, plums, apricots, nectarines)

Rhubarb

Pears

Tomatoes

High Pectin fruit:

Apples

Citrus (oranges, lemons, grapefruit)

Cranberries

Grapes

Quince

What kind of sugar should I use when making jam?

As a rule of thumb, I recommend only using granulated sugar when making jam. Brown sugar contains molasses, which can impact the flavor of your jam as well as the cooking process. Other sugar varieties, such as sucralose, will not allow the jam to set. Liquid sweeteners such as honey and maple syrup can add a nice flavor to jam, but they should never be used as the sole sweetener. They are too viscous and cause scorching and boiling issues as the jam cooks over a prolonged period of time. If you want to swap in some honey or other sugar for added flavor, I suggest swapping in no more than 1/2 cup / 110 grams for the same amount of granulated sugar.

Do jams need acid?

Jams need acid the same way they need sugar. Both help activate pectin, but acid also provides a key layer of balance. Jam is naturally quite sweet, but without an acid to intervene, nearly every jam would be cloyingly sugary.

My rule of thumb is one tablespoon of acid per pound of fruit. So if you are making jam with 3 pounds of peaches, you’d want 3 tablespoons of lemon juice, and so on, so forth.

What needs to happen to properly can jam?

There are two things you need to do when making jam you wish to preserve:

1) Sterilizing your jars and

2) Processing your jars

Both of these processes can rely on fancy equipment, but I’m going to discuss how I do it with layman kitchen tools.

1. Sterilizing your jars

First you want to acquire jars that are suitable for canning. Most jars will indicate if they are either on their company website or on the packaging. These jars will have rubber-sealed lids where the top of the lid is separate from the screw-top cap.

Lids cannot be reused for canning, so make sure you have all new lids.

To sterilize your jars, set a large pot of water on the stove. If you have a rack of some sort to put in the bottom of the pot, great. You want water to be able to reach fully around your jars as much as possible.

Place the jars in the pot of water and make sure they are completely submerged (check for air bubbles at the top! Those are a big no-no).

Boil the jars for 15 minutes, then use tongs to transfer them onto a clean dish towel. I like to “tap” the jars’ mouth on the dish towel to make sure any excess water is gone, then flip them to let them dry out right-side-up.

I try to do this step during the last 15 minutes my jam is cooking, because it’s good to have the jars as warm as possible before adding the jam.

2. Processing your jars

Processing your jars just means properly sealing them. The way that jarring works is that the food inside boils, causing pressure and pushing air out to vacuum seal in the food. It’s best to do this as precisely as possible.

Fill the jars with jam when the jam is still hot. This will help the rubber lids vacuum seal to the jar. I fill my jam as close to the top as possible while leaving 1/4-1/2 inch of space to prevent overflow.

Add the rubber seals to the top of the jars and screw on the lids until just shy of fully on. This is so that the jars can process under the heat of the water.

Next, use tongs to place the jars into the pot of boiling water, ideally with the wire rack still at the bottom. You want the jars submerged by at least 2-inches, with boiling water surrounding them.

If the jars can be stored fully upright, that’s the best way. However if your pot is smaller, like mine, I tilt my jars to the side but ensure that the headspace (ie. the space in the jar without jam), is still mostly in contact with the roof of the lid. This ensures that when pressure builds in the jar, the air is still released through the lid. If the headspace is trapped at the bottom of the jar, then it will not process properly. So if you are going the tilting route, be sure to monitor your jars.

You will want to boil your jam for at least 15-18 minutes. If you are making jam at altitude, you will need add an extra minute per 1000 feet.

Once that time period is over, use tongs to pull the jam from the pot and transfer the jam to a dishtowel. Use a dishtowel or oven mitt to protect your hands as you tightly screw on the lid to the jars. Let these cool fully to room temperature, which can take up to six hours.

When the jams are done processing, the lid should be concavely adhered to the jar and unable to pop. And there you did it! Processed jars of jam!

Do I need to do the extra steps of processing my jam?

Absolutely not. If you want to skip the steps listed above, you can just make this delicious jam, allow it to cool in any container you prefer and store it in the fridge for 2 weeks. It will keep just fine, it will just need to be refrigerated!

What jars are best for making jam at home?

I prefer wide mouth jars for when I am making jam at home. It’s much easier to scoop the jam directly into them, and they are easier to clean and sterilize. Ball Jars has various sizes to choose from, along with other canning tools and resources, if you are interested!

Can I apply these ratios to any jam?

Absolutely! What I like about jam is similar to bread, you can start off using someone else’s ratios, and then mix and match it to your own. For example, I think this peach jam ratio works well for other fruits such as strawberries, cherries, blueberries and apricots. Of course, as you try more fruits your opinion might differ, so you can add more or less sugar as you become more comfortable with canning!

For any jam recipe, these are the amounts I like to rely on:

4 pounds fruit (measured after the fruit has been pitted/peeled)

1 pound 5 ounces / 595 grams granulated sugar

4 tablespoons lemon juice (or acid of choice)

That is the base recipe, but here are some flavor additions that I think work wonderfully with jams

Cloves – Add 2 tablespoon of whole cloves when you add the acid

*Goes well with strawberry, rhubarb or plum jams

Cardamom – Add 2 tablespoons of whole cardamom to any jam when you add the acid

*Goes well with orange marmalade, peach, and nectarine jams

Ginger – Add 1 tablespoon freshly grated ginger to any jam when you add the acid

*Goes well with blueberry, blackberry and stone fruit jams

Cinnamon – Add 2 cinnamon sticks to any jam when you add the acid

*Goes well with apple, pear, and quince jams

And now that you know the “how” and “why” of making jam at home, let’s get into this Peach Saffron jam recipe!

Again, this recipe + blog post work well as a pair, so I recommend reading the blog post first, then you will be fully ready to embark on this recipe!

Happy jamming, everyone!

Watch the recipe here

The video may not fully represent the recipe. For best results, follow the instructions as written.