Cider Quiz Answers: Question #10

1. The dominant sugar in apples is fructose versus glucose in grapes: Incorrect Answer – While this statement is true, it is not the correct answer for this quiz. Fructose and glucose are both monosaccharides often called simple sugars or reducing sugars. Chemically, they both have the same general formula, C6H12O6. However, they are not the same. They are different because the carbon, hydrogen, and oxygen molecules are arranged differently. Humans process these sugar differently because of this difference in molecular structure. Yeast process them differently too. Some yeast prefer glucose, Saccharomyces generally does. Apples naturally tend to have higher levels of fructose sugars while grapes tend to have higher levels of glucose. The yeast you use to ferment will perform differently in a juice with more fructose than in one with more glucose. The yeast will use nutrients differently. This can result in different aromas, fermentation performance, and residual compounds. The characteristics of a yeast identified by fermenting wine may not be the same characteristics when fermenting cider because the fundamental sugars are different. Just like beer makers don’t tend to use wine yeast for making ale, why should cider makers use wine yeast for making cider? Because the type of sugar and aromatic profiles we want differ between cider and wine, the yeast we use probably should as well. I recommend exploring non-Saccharomyces strains like Lachancea thermotolerans, Pichia kluyveri, and Candida zemplinina to create unique ciders.

2. The average sugar content in apple juice is 2-3 times lower than grape juice: Incorrect Answer – While this statement is true, it is not the correct answer for this quiz. Besides having different types of sugars, apples and grapes also have significantly different amounts of sugar. Grapes contain a much larger amount of sugar per weight than apples. Apple juice commonly has a specific gravity, measure of dissolved solids like sugar, around 1.050. Grapes are usually over 1.100, or twice as much. Obviously, variety and environmental conditions play a big factor in this. I have picked apples with a specific gravity of 1.102 but that is not common. The important element here is the amount of sugar. The high sugar levels in both apples and grapes will cause stress to yeast, but it also causes yeast to need more and different nutrients to process these sugars. Just like the type of sugar matters, the amount of sugar matters. Is the sulfur odor created in wine because of low nutrients the same created in cider? Sulfur odors were found to be created by both too little and too much nutrient, especially easily processed inorganic nitrogen. Should cider be made with added nutrients? If so, what type of nutrient should be used? Do you use inorganic nitrogen commonly found in most commercial “yeast nutrients” or should you use organic nitrogen found in yeast derived products (YDP), which not only provide nitrogen but other compounds used to create aromas and flavors. 

3. Malic acid is the dominant acid in apples versus tartaric acid in grapes: Incorrect Answer – While this statement is true, it is not the correct answer for this quiz. Up to 90% of the acids found in apples can be malic. For grapes, up to 90% of the acids are generally malic and tartaric acids with tartaric being the dominate of the two. Why does this matter? Malic acid is more acidic and less stable than other types of acids like citric, lactic, and tartaric. With low residual sugar, cider will tend to be more acidic and less stable than a wine with a lot of tartaric acid. This makes cider more at risk or in “need” of a stabilizing reactions, like malolactic fermentation. Only recently have wine makers considered the broader benefits that malolactic fermentation (MLF) can have for all wines. While this is starting to change, cider has always been in need of its benefits. Yet, the use of sulfites (Campden and such) in cider that was carried over from wine’s needed protection against Botrytis cinerea influence and desire to avoid MLF may be the greatness harm done to the cider industry in its history. You want to reduce and stabilize the malic acid found in cider and the best way to do this is with lactic acid bacteria. Just like all sugar is not the same, neither are all acids. How you deal with those acids is also critical. I recommend encouraging lactic acid bacteria, not suppressing it.   

4. All of the Above: Correct Answer – As noted above, answer 1, 2, and 3 are all correct so the correct answer to this question is 4, which is all of the above. 

5. None of the Above: Incorrect Answer – As noted above, each of the above statements are true so this answer is not correct.