Let's Talk Sugar: Part 01
Let’s Talk Sugar: Part 01
One of the most common questions I hear when teaching Wiley Workshops is:
Can I reduce the amount of sugar in a jam recipe?
The honest answer is, “Yes, only to a certain degree, and only if you understand what role sugar plays in the jar.”
Sugar is not only there to make jam delicious and sweet. In traditional jam-making, sugar is also a structural ingredient. It’s part of the chemistry that helps fruits and vegetables become spreadable and stable.
Today, in Part 01, let’s discuss exactly what roles sugar plays in the jam-making process.
Next week, in Part 02, we will discuss what happens when you reduce it, and why certain substitutes, particularly honey, behave differently than we might expect.
Sugar plays three key roles in the jam-making process.
01: Sugar helps jam set.
02: Sugar interplays with water.
03: Sugar enhances the inherent flavor of the fruit itself, as well as adds sweetness and vibrancy.
01: Sugar helps jam set. The ‘set point’ of jam is the point at which it reaches desired consistency. For most classic jams, this occurs at about 220°F at sea level. Most classic jams also rely on pectin, a naturally occurring polysaccharide found in fruit. It is also often added as a commercial product, and this commercial product is often made from apples. Pectin molecules form a network that helps trap liquid. This is what helps give jam its gel. Sugar behaves in support of this. Sugar is a disaccharide, and this structure matters. Granulated cane sugar is sucrose, a disaccharide made of two simpler sugar molecules: glucose and fructose, bonded together. Because sucrose is a larger molecule, it interacts with water and pectin in a more predictable and structured way than single-unit sugars do, such as glucose and fructose, which compose honey. In the presence of heat and acid, sucrose helps create an environment where pectin molecules can move closer together and form a stable network. This contributes directly to the reliability of a jam’s set.
02: Sugar interplays with water. In a pot of cooking fruit, there is a lot of water, much of which is released as the fruit breaks down when we mash or blend it. Sugar is hygroscopic, meaning it binds readily with water. When sugar is present in a sufficient quantity, it ties up water molecules that would otherwise be “free” in the mixture. This matters for texture and spreadability. Too much free water can lead to jam that is not properly set. Very importantly, sugar also helps reduce water activity. Low water activity is a hallmark characteristic of shelf-stable jam. Traditional jam is preserved, in part, because sugar lowers water activity, the amount of water available for microorganisms to use. Microbes need accessible water to grow. Sugar reduces that accessibility. This is why very low-sugar jams often have a shorter shelf life, especially after opening, even if they’re processed correctly.
03: Sugar enhances the inherent flavor of the fruit itself, as well as adds sweetness and vibrancy. Sugar sweetens, of course, but it also balances acidity and bitterness and can amplify fruit aroma.
Next week, we will discuss what happens when sugar is reduced and how honey is often used as a partial replacement. As always, please reach out with any questions.