As an experienced brewer and sommelier, I can confidently say that the best sugar for priming beer is a type known as “simple sugars” or monosaccharides. These sugars are easily fermentable by yeast, resulting in a clean and efficient fermentation process.
One of the most common simple sugars used in brewing is fructose. This sugar is naturally found in fruits and provides a subtle sweetness when used in beer. I have personally used fructose in several brews, particularly when aiming for a fruit-forward flavor profile. It can be a great option for adding complexity to certain beer styles, such as fruit-infused ales or Belgian beers.
Another commonly used simple sugar is glucose, also known as dextrose. Dextrose is derived from corn and is highly fermentable. It is often used in brewing because of its high solubility and ability to fully ferment, leaving no residual sweetness in the finished beer. I have found dextrose to be particularly useful when brewing light lagers or pale ales, where a crisp and dry finish is desired.
Galactose is another monosaccharide that can be used in brewing, although it is less common compared to fructose and glucose. It is naturally found in dairy products and has a slightly different flavor profile compared to other simple sugars. While I haven't personally used galactose extensively in my brewing, I have come across some experimental recipes that incorporate it for unique flavor characteristics.
The best sugar for priming beer is a simple sugar such as fructose, glucose (dextrose), or galactose. These sugars are easily fermented by yeast, resulting in a clean and efficient fermentation process. Each sugar brings its own unique flavor profile, so choosing the right one depends on the desired taste and style of the beer being brewed.