It’s a common misconception that sugar is only used for making food and drinks sweet. While sugar does sweeten food, it holds many more functions in bread making than just the flavour. So, “Why is there sugar in bread?”, “What does sugar do to bread?” and “Is it essential to include sugar in a bread recipe?”. I asked myself the same questions, and here’s what I found out.
Sugar is included in many types of bread as it serves many functions outside of simply adding sweetness. Let’s take a look at each one:
Yeast cells are living organisms which need food for their metabolism. Sugar, or its scientific name, sucrose, is a disaccharide made by bonding two hexose sugars, fructose and glucose. Yeast produces enzymes that can break sucrose down the bonds to separate the hexoses. They will then enter glycolysis, where they are simplified further. After this, they will either produce carbon dioxide and water through the Krebs cycle or carbon dioxide and ethanol in alcoholic fermentation.
A traditional bread dough that does not contain sugar will use enzymes to break down starches found in the flour into the simple hexose sugars needed to supply the yeast. With the addition of sugar, yeast operates at a much faster rate by quickly consuming the sugar and releasing carbon dioxide. This results in a faster rising of the bread.
If sugar and oxygen are available, yeast will engage in aerobic respiration to produce C02. But when sugar and oxygen are depleted, the yeast is starved and switches from aerobic respiration to anaerobic respiration. For standard yeast bread, this leads to alcoholic fermentation and ethanol production. The ethanol mostly evaporates during the baking process, yet some aroma remains that perfumes the bread.
Note: Aerobic respiration is more efficient at producing carbon dioxide than fermentation is. This means that your bread dough will rise faster and benefit from a more significant gain in the oven spring.
Knead your dough intensively to incorporate plenty of oxygen for a lighter-tasting loaf. Adding sugar to the recipe will provide readily available food for the yeast. Your dough will rise with minimum fermentation time and produce a lighter-tasting bread.
Not all of the sugar gets consumed by yeast. The combination of table sugar with sugars derived from the breaking down of moistened flour can produce a lot of sugar. Any excess sugars not processed by the yeast have the potential to provide sweet flavours in the bread, though not all sugars taste sweet.
The improvements in texture occur as sugar tenderises the gluten strands. A dough containing plenty of sugar builds strong bonds with water molecules. The bonds prevent water from being available to the gluten and the yeast (called osmotic stress). This produces close-knit gluten bonds, which reduce the dough’s ability to stretch. As the dough is not as stretchy, sugar in bread leads to a softer textured crumb.
Adding a small amount of sugar will result in a compact textured breadcrumb. This makes sugar great for rolls and dinner bread. While a more significant amount of sugar gives a light, fluffy texture, just like for cakes and other pastries.
Sugar retains water which makes baked goods moist. It also locks in the moisture in the crumb structure, slowing the rate at which water can escape. By retaining moisture better, the enriched bread keeps fresher for longer.
Who doesn’t love those deliciously sweet brown edges of the bread, right? Well, this browning is mainly due to Maillard’s reactions. These enzymic reactions occur when proteins are heated in the oven. But the inclusion of sugar in bread dough increases caramelisation as well. This adds colour and sweeter notes to the crust, adding a smoky aroma throughout the loaf.
Sugar can have a significant effect on the dough used in bread. It improves the texture and colour of any baked good, as well as extending freshness. But arguably, the most prominent role of sugar in the bread dough is providing food to accelerate yeast activity.
Sugar can speed up the rise time during the proofing period. You should be careful not to add too little or too much. Straying far away from a recipe can have a negative effect on your dough:
Yeast feeds on sugar to produce carbon dioxide gas that will make the dough rise. So, if there’s less sugar, the rising process will be slower, and fewer of the above effects will be prominent.
Adding too much sugar to the dough can also slow down or inhibit yeast activity. Sugar absorbs water. When there is too little water to conduct osmosis (the passing of nutrients between cells), yeast activity slows. In severe cases, the yeast becomes dehydrated, and gas production is halted.
Bread dough is high in sugar when it contains more than 1/2 cup of sugar for every 4 cups of flour or above 10% as a baker’s percentage of the flour. If adding this much sugar to bread dough, you will need to use more yeast (3%) or an osmotolerant yeast.
Sugar creates osmotic pressure in bread dough which slows down the effectiveness of the yeast. A little bit (less than 5%) of sugar will make a minimal impact but expect gas production to slow when using more than 10% sugar due to osmotic pressure.
Whilst it is possible to add more yeast to the recipe to compensate for this, the bread can take on the odour and taste of yeast. The best solution is to use osmotolerant yeast. This is a special type of yeast that copes well under osmotic stress. It’s a lot more expensive than standard yeast types and only comes in a dried instant yeast format. Being dried, osmotolerant yeast keeps for a reasonably long time. The extra potency means you can make sweet bread such as doughnuts, challah and panettone with ease and consistency.
The amount of sugar in bread varies by its different types. But most sliced bread contains about 2-4% of sugar content. Most of the sugar found in bread is naturally occurring and not added. Raw flour contains naturally occurring sugars, with approximately 1.4-2.1g for every 100g of flour. As starch gets broken down into simpler sugars, the amount of sugar absorbed when digested is higher.
Flour is made from grains, composed mainly of starch, protein, dietary fibre, and minerals. The amount of sugar in flour depends on the grain variety and its growing conditions.
It’s pretty common nowadays to see sugar as an ingredient in bread. With all the benefits of adding sugar, you can see why sugar is used in commercial production. Although, the extra calories and quick production aren’t all that good for us!
White bread is high in carbs and low in fibre. This combination can result in higher blood sugar levels. Besides that, health experts don’t advise that we consume a lot of white bread because:
It is common for bread to contain a small amount of sugar. However, some types of bread may contain more than you expect. If you want to make sure that you’re eating healthy, always carefully read the nutrition facts on the label.
Malt is made by soaking barley in water until it sprouts, drying and grinding to flour. It comes in two forms, non-diastatic and diastatic.
Non-diastatic malt is a sweetening agent. It isn’t the same as sugar but can be a form of sweetener in syrup form. It has a distinct flavour, and it’s also used for making many yeast-leavened baked products. Compared to other sweeteners, malt is considered more nutritious, so some bakers prefer to use it when making bread.
Diastatic malt flour is regularly used to add more of the enzyme called alpha-amylase. This increases the rate at which starch is broken down into simpler sugars. Malt flour is perfect for poor-performing flours and provides natural sugars in bread (and the benefits the bread will enjoy) without adding extra sugar. Only a little is required. Overuse can cause a sticky bread texture.
Malt is available in the form of:
Today we’ve learned all about the impact of sugar in bread dough, what it does and what too much of it does! I’m sure you have suspected a few of them, but hopefully, you’ve learned one or two new impacts of adding sugar. I know I have! Let me know in the comments below what you found helpful and perhaps what you’ll try in the future.