Sugar by Miranda Kohout

From a molecular standpoint, sugars are the simplest carbohydrates. From a chef’s perspective, that’s where the simplicity ends. We spend a lot of time trying to bend this building block of confectionery and pastry to our will, knowing it can crystallize when we’d prefer it didn’t or remain fluid when we need it to crystallize. We understand its impact on qualities such as texture, color, structure and shelf life, but flavor trumps all, and striking a balance is critical.

“Sugar” or “Sugars?”:

For our purposes here, we’ll refer to the general category of sugars (sucrose, fructose, lactose, etc.) as “sugars” and refer to specific sugars by name when it is important to differentiate.

Different Sugars and Their Properties

Sucrose: This is the scientific term for table sugar. Some chefs will use the word “sucrose” in their recipes instead of “sugar” to avoid confusion. “Sugar” could, technically, mean many things, but only sucrose is sucrose. Sucrose is a disaccharide, meaning it is composed of two molecules: one each of glucose and fructose.

This familiar ingredient is a chef’s go-to for sweetness. It is inexpensive and readily available, and its flavor does not change as its concentration in a recipe increases. However, it is prone to crystallization, and the crystals it forms are very hard and unpleasant to eat. Anyone who has ever cut their hand (or lip!) on a sugar garnish knows sucrose isn’t perfect for every application.

Glucose: Glucose is created when a starch undergoes the process of hydrolysis: the starch is combined with water and an acid, causing a chemical reaction that splits the starch into glucose and maltose and leaves some complex starch molecules behind.

These starch molecules determine glucose’s dextrose equivalent (DE). The DE indicates approximately how many of the bonds in the starch have been broken down into dextrose. Commonly available glucose syrup has a DE of around 42 – 43%. The higher the DE, the sweeter the product.

Glucose is excellent for lowering the freezing point of ice creams and sorbets, helping to stabilize ganache and preventing crystallization in various applications.

Glucose powder is simply glucose syrup with all the water removed and is used when the properties of glucose are desired. However, the excess water in the syrup form would be detrimental, as in a sorbet or ganache.

Dextrose:

Unlike glucose, the starch hydrolysis reaction producing dextrose is complete, leaving no complex starch molecules behind. Therefore, dextrose has a DE of 100.

Dextrose and atomized glucose are identical in appearance; both come in the form of a fine, white powder. To complicate matters, they are almost chemically identical, and glucose powder is sometimes even marketed as dextrose. However, they have very different properties, and a food chemist will tell you that a dextrose molecule is, in fact, a mirror image of a molecule of glucose. Think of it this way: even though a left-hand glove and a right-hand glove are essentially the same, you cannot wear your left glove on your right hand.  

Dextrose is sweeter than sugar, has a slightly higher moisture content, and is far superior to glucose powder at extending the shelf life of a confectionery ganache.

Invert Sugar:

Most chefs know invert sugar by their preferred brand name, as they would facial tissues or cotton swabs. Trimoline® and Nevuline® are two common brand names for invert sugar, the thick, often opaque, syrup made by breaking the bonds between sucrose’s glucose and fructose molecules. The amount of whole sugar molecules remaining in the syrup varies from manufacturer to manufacturer.

Invert sugar is around 1.5 times sweeter than sugar. It is excellent for depressing the freezing point of an ice cream or sorbet, preventing crystallization and creating a soft texture in baked goods and ganaches.

Honey’s properties are nearly identical to those of inverted sugar, but it contributes a distinct flavor that may or may not be welcome in an end product.

Other sugars:

Many other sugars are seen less often in the kitchen, but that is not to say that they are off-limits or avoided. Lactose, maltose, sugar alcohols such as erythritol and sorbitol, and starches such as inulin have specific properties, advantages and disadvantages.

Sugar Refining

Sugar refining has evolved somewhat since its beginning. Today, whether the source is sugar cane or sugar beets, the raw, unrefined sugar is crystallized in factories near where it is grown, and it is shipped to industrial countries that are the major consumers of sugar for refining.

For both cane and beet sugar, the juice must first be extracted from the vegetable matter. It is filtered to remove impurities, leaving behind a syrup. The sugar within the syrup is crystallized, then the syrup containing the sugar crystals is spun in a centrifuge to separate the solid crystals from the liquid syrup (molasses). The crystals are whitened and refined using carbon or charcoal, which is then filtered out.

To create brown sugar, producers add a small amount of molasses back into the whitened, highly refined sugar. This ensures a more consistent product than they would achieve by allowing some molasses to remain. The added molasses slightly increases the sugar’s acidity, which may impact some products, particularly baked goods. Swapping sugars should be approached with care.

Sugar can also be extracted from coconuts, dates, and palms. The sugars produced are notably different in color and flavor from cane or beet sugar.

Unrefined Sugars

Many consumers turn to unrefined sugars, hoping to mitigate the adverse effects of highly processed sugars. Chefs are also looking to alternative sugars, not only because their customers are asking for them, but because they offer a unique flavor and culinary history. Unrefined sugars such as panela, piloncillo, kuro sato, and kokuto have colors and flavors that enhance a pastry creation and add a depth of flavor unmatched by plain white sugar.

Effect on Other Ingredients

Egg Whites: Sugar encourages egg-white proteins to coagulate. If you add sugar to egg whites for a meringue too soon, many of the proteins will bond and prevent the whites from being sufficiently aerated during the whipping process.

Egg Yolks: Sugar draws water from the egg yolk, forming small clumps. Though no cooking occurs, many refer to this as “burning” the yolk.

Yeast: A small amount of sugar can help increase yeast activity, thereby acting as food, but too much sugar will interfere with yeast function. Sugar can pull water out of yeast cells, as it can with egg yolks, affecting yeast action and lowering product volume.

Gluten – Sugar competes with gluten for available water, weakening the gluten structure. Weakening occurs at concentrations greater than 10% of flour weight. (McGhee, On Food and Cooking)

Fruit – Fruit preparations are where sugar’s hygroscopic (water-loving) tendencies work to a chef’s benefit. Like salt, sugar changes the osmotic pressure of an environment. Because sugar molecules are too large to penetrate the fruit’s cells, they will draw the water out of the fruit until the sugar solution outside the fruit is equal to that inside the fruit, resulting in drier fruit more appropriate for baked applications, and a fruit syrup, which can be brushed on cakes, drizzled on ice cream, or reduced to make a sauce or garnish.

Sugar’s Role in Recipes

In Baked Goods
Sugar contributes moisture to cakes, cookies, and breads, aids browning and aeration, increases tenderness, and adds flavor.

In Ice Cream

Sugar’s ability to depress the freezing point of ice cream, keeping it scoopable at very cold temperatures, is its most notable contribution to ice cream and frozen desserts. With an AFP (Anti-Freezing Power) of 100, Sucrose fulfills this role well but adds a great deal of sweetness. A mixture of different sugars is ideal for successful ice creams.

The ideal amount of all sugars in an ice cream base is 12% – 16% of the total weight. For a sorbet, the recommended amount is 25 – 30%. Amounts outside these ranges can also work, depending on other ingredients and desired results.

In Preserves

Sugar allows for the room-temperature storage of many foods by bonding with the water that would otherwise be used by microbes. In a process called plasmolysis, the fruit cells contract as the water exits, leaving less room for microbial cell growth.

Of course, factors beyond sugar content come into play in preservation, and other ingredients allow for preserving foods that do not add sweetness. However, bakers and pastry chefs are primarily concerned with preparations such as jams and jellies. Both rely on a specific sugar concentration to prevent microbial activity.

In Candies

The preservative effects of sugar are evident in candies such as pâte de fruit (fruit jelly) and the long shelf life of confections such as marshmallows, toffee and hard sugar candies.

In Ganache

Once again, sugar’s primary role beyond flavor is to act as a preservative using its water-bonding capabilities. The varying properties of different sugars can make them better suited to use in ganache, and most well-balanced ganache recipes will employ more than one type of sugar to achieve the chef’s desired results.

In Fermentation

While chefs seek to prevent microbial growth in almost all their products, preserving by fermentation is the exception. A high sugar concentration will stunt microbial growth; a low concentration encourages it, and the growth of the right microbes is the goal of preserving via fermentation. Most of the foods a pastry chef might seek to preserve by this method contain enough inherent sugar to do the job, but in certain instances, adding sugar may enhance or accelerate the process.

On Flavor

While sucrose offers a clean, pure sweetness with no other flavor, unrefined sugars can add toasty, spicy or tropical nuances. All sugars help balance the other major taste categories, mitigating heat/spiciness, taming bitterness and playing off sourness. The sweetness of sugar gets a little boost from umami and often works well with spices. The perception of a rich or fatty item gets bumped up to “indulgent” with the addition of sweetness.

Caramelization

In the simplest terms, heating sugar results in caramelization. On a molecular level, caramelization is an incredibly complex process. When we heat sucrose, we see it begin to “melt.” While sucrose does liquify, decomposition is the proper term for what is happening. At around 186°F (scientists declared pinpointing an exact temperature impossible), the structure of sucrose breaks down, and it splits into glucose and fructose. Once the split has occurred, water from the sucrose evaporates, and the individual sugars can caramelize. Sucrose will split faster in the presence of additional water or an acid. Gentle heat can result in decomposition without liquefaction, as seen when toasting sucrose. Heating sucrose gently over a long period results in the splitting of the sucrose molecule and the caramelization of the individual components without causing it to liquefy.

From a practical standpoint, using sucrose in a dough or other applications does not enhance browning significantly compared to browning caused by honey or corn syrup. Sucrose is less reactive than its component sugars, and, in the case of a cake or pastry cream, it has not and will not split into glucose and fructose. This is why, for example, the sugar for a caramel ice cream or pastry cream must be caramelized first in order to lend its signature color and flavor to the end product.

Crystallization

Sugar crystallization begins with a “seed.” A seed can consist of a few sugar molecules that happen to bump into one another and form a bond, or it could consist of  an impurity or introduced ingredient. Crystallization begins at the molecular level, so the impurity needn’t even be visible for a seed to form. Uneven heating and cooling can cause the formation of seeds, as can stirring and agitation.

For candies such as fudge, the formation of many very fine sugar crystals is required to produce the classic texture. This is achieved by vigorous stirring, which creates so many crystals that the sugar molecules available to form larger crystals become scarce, leaving a collection of tiny sugar crystals.

Temperature is critical when you create sugar sculptures, hoping to create an effect that resembles glass. The sugar syrup must cool so rapidly that the sugar molecules stop moving before seeds (and, therefore, large crystals) can form. The absence of crystals results in a glass-like effect.

Ingredients That Limit Crystallization

Invert Sugars

Glucose and fructose, present in invert sugars, prevent crystallization by bonding to the seed surface and preventing other sucrose molecules from latching on and forming larger crystals. The long glucose chains in corn syrup essentially “tie up” the sucrose and water molecules and prevent them from interacting.

Milk Proteins and Fat

While ingredients such as cream and butter are added to confections for many reasons, preventing crystallization is not one of them. However, they will interfere with crystal formation to some extent.

Acid

Acid causes sucrose to invert, the very definition of anti-crystallization. Acid can be a crucial flavor component, particularly in candies with sweetness that can overwhelm, so it is often added to syrup only after it has cooled in order to avoid excessive inversion.

Reducing Sugar

As sugar’s effects on health become clearer, efforts to reduce sugar consumption have intensified. Humans’ attraction to sugar is rooted in its role as a building block of life, so less-sweet versions of our favorite foods simply don’t appeal to us at a fundamental level. Even if they did, sugar contributes much more than sweetness. If flavor were sugar’s only contribution, reducing sugar in our diets would simply be a matter of eliminating it from our recipes.

While sugar cannot simply be removed entirely from recipes, in some instances a reduction of sugar up to 50% can produce results comparable to those seen with the full amount of sugar. Begin by reducing the amount of sugar by 5% and keep testing incremental reductions. If you work in baker’s percentages, a good rule is to aim for 85 to 125% total sugar in a recipe.

Attempts to create a sugar-like substance that offers the attractive flavor of sugar and its ability to tenderize, brown, preserve and aerate have met with limited success. Sugar substitutes almost always require some compensation on the part of the chef in terms of flavor, texture or color, though there have been breakthroughs in food technology that offer promising results. For now, chefs look to additional ingredients to compensate when sugar substitutes fall short or may alter methods, temperatures and more to achieve the results their customers expect.

Trivia: Is Sugar Vegan?

Sugar comes from plants. Of course it’s vegan!

While sugar itself is not derived from animals, it is important to note that animal byproducts may be involved in the processing of cane sugar. The charcoal or carbon utilized in the whitening process may originate from coconut ash or other plant-based sources, yet it may also be derived from bone char. Different whitening materials necessitate distinct processing equipment, and transitioning to plant-based refining techniques mandates sugar manufacturers to procure new equipment and modify their processes. Nevertheless, numerous sugar manufacturers in the U.S. have made this transition. Additionally, it is possible to research the method used at specific refineries if a sugar’s vegan status is of concern.

It is worth noting that the whitening process is not essential for beet sugar. As most European countries rely on sugar beets rather than sugar cane for their table sugar, the vast majority of sugar in Europe is considered vegan. Moreover, the use of bone char disqualifies a sugar product from obtaining the USDA “organic” label. Therefore, any cane sugar labeled as organic in the U.S. is indeed vegan.

(This article appeared in the Summer 2024 issue of Pastry Arts Magazine)