References to the use of sugar in certain production steps are often found in homebrewing recipes found online or in homebrewing books. Sometimes it is referred to only as sugar, others as corn sugar and still others as cane sugar or table sugar, creating confusion and the risk of making mistakes.
One of the most frequent doubts is about the difference between cane sugar and corn sugar. To answer this question, we must first lay some groundwork on adjuncts and their use in brewing, with a particular focus on homebrewing recipes.
Adjuncts are defined simply as sources of extract (sugars) other than malt. A wide variety of materials may be used. They may be employed purely on the basis of cost or because they impart desirable properties to the beer which may not be achieved by the use of malt alone. Commonly particular adjuncts may be used in certain geographical locations where they are plentiful and inexpensive, other adjuncts may be used for a historical purpose.
Some beer styles expect some sort of adjuncts in recipes (English bitter, some Belgian ales, etc) while other styles strictly forbid (as German styles that follow the Reinheitsgebot rule).
Adjuncts are typically derived from various cereals (rice, corn, sorghum, etc) and may be liquid or solid. In the case of liquid types, they take the form of various sugar syrups. From a homebrewing point of view, we will focus mainly on these sugar additions, as these are the most commonly used. Now we will see why.
Sugar in homebrewing
There are three main reasons to use sugar in homebrewing. Priming for fermentation is the first. Small amounts of sugar are added to the bottle during the bottling phase. Once corked and sealed, the still active yeast in the bottle will consume the added sugar, creating natural carbonation within the beer. This is done because with a domestic setup it is not easy to have the equipment to ferment without loss of CO2, and without bottle conditioning, the beer would become flat.
In addition, the process of converting the added sugars by yeast allows the small space of oxygen left between the cork and the filling level to be consumed and this avoids major oxidation problems. Raising the alcohol level without increasing the body of the beer is the second reason for sugar use in homebrewing.
When added, sugar is converted into alcohol by yeast. Since ethanol is lighter in weight than water, allowing you to produce a more robust beer without making it heavy. This is the method used in the production of many Belgian beers or some Double IPAs. Flavouring and colouring are the last reason. In this case, alternative sugars should be used, like molasses or honey.
While corn and cane sugar doesn’t impact flavour (if used carefully), other forms of sugar could affect the beer profile. Now that we have the basics on what adjuncts are and why they are used in homebrewing, we can proceed to learn about the differences between two sugars that are often mentioned (and confused): corn sugar and cane sugar.
Corn sugar is one of the most widely used sugars in homebrewing, especially in America. It is more difficult to find in Europe but can be found on some websites specialising in homebrewing materials. It is often also called brewing sugar or dextrose. It consists of 95% solid components and 5% moisture. The solid part is glucose, a highly fermentable monosaccharide.
Corn sugar is highly-refined and has no corn character. Given its simple chemical composition (compared to other sugars), it is highly fermentable. It should only be used if the recipe calls for it and only in the prescribed quantities. In fact, too high a sugar quantity could stuck the fermentation of the beer. It can be used both in priming and/or to alter the alcohol content without adding weight to the body.
Cane sugar, also called table sugar, is the reference for fermentable sugars. It is often used in Europe due to its easy availability and low cost. It consists of 100% solid material, so it ferments more on an equal weight basis with corn sugar, since there’s no moisture. Chemically, it is a disaccharide, a compound made of two monosaccharides: glucose and fructose.
The presence of fructose is sometimes mentioned as a risk factor, as it could impart a greater ‘sweetness’ to the beer, but there is no clear evidence that this is true. A substitute for cane sugar is beets sugar; both are marketed under the name table sugar and are indistinguishable from each other. It has no impact on the beer’s flavour profile and again can be used either for refermentation or to modify the alcohol content by lightening the body of the beer.
Now that we have all the data, we can finally answer our question. As evident from above, both sugars perform the same function. The only important difference is in terms of yield. If the recipe calls for a certain amount of cane sugar and we want to use corn sugar instead, remember to add about 10% more. Conversely, we will use 10% less if we switch from corn sugar to cane sugar.
This is the only obvious difference between the two products. Given the minimum percentage of use in relation to the total of the recipe, there are no further precautions to follow, and both can be used for priming or for alcohol addiction. On many homebrewing forums, there is also talk of differences in fermentability and possible aromatic contributions, but in more serious texts these issues are not mentioned, so it is best to ignore them.
An ideal way to assess the differences with our mouth is to split a production batch in half and use the two sugars for priming the same wort. In this way, we could directly assess the presence of any differences between the two finished products in terms of aroma and/or taste.