# Proper way to calculate the amount of sugar in a drink

I have recently read an article (in Spanish) about a sugary drink (water-based) with stated the following facts:

• Ingredients of the drink: natural mineral water, organic cane sugar, lemon juice made from concentrate (7.9%), ascorbic acid, pectin, natural basil flavoring, natural lemon flavoring and other natural flavorings.
• Nutritional values per 100 ml: 18 kcal and 4,1 grams of sugar.

I'm trying to calculate where did that amount of sugar per 100 ml come from. The list of ingredients must be ordered by weight in decreasing order by Spanish law. We do not know the percentage of sugar, but we know it must be at least a 7.9% (the percentage of the following ingredient) of the weight of the product. The nutritional values are calculated per 100 ml, but the density of this drink (as it is not a carbonated drink) must be around 1 kg/l. So asuming that 100 ml of this drink weight approximately 100 grams, in that amount there must be around 7.9 grams of sugar, and not 4.1 grams as the label states (if we do not add the amount of sugar in the lemon juice). Besides, those 7.9 grams of sugar must contain 28 kcal, above the 18 kcal stated.

So given the discrepancy, and assuming good faith on the side of the company that manufactures the drink (and assuming the article copied the values properly from the label), where did I go wrong?

• Assuming "The list of ingredients must be ordered by weight in decreasing order by law" is true where you are, is it true where your source is/where the drink is on sale (and assuming no typos)? Is it possible to link to the article (even if not in English)? Commented Oct 25, 2018 at 13:04
• The density of a sugar solution will be slightly above that of pure water, but I very much doubt it will make much difference Commented Oct 25, 2018 at 13:06
• @ChrisH article linked, and yes, in Spain the law states the ingredient list must be ordered by weight. I'm assuming no typos in the article, but the list of ingredients have been confirmed in the official web page of the product (which did not include the nutritional values). Commented Oct 25, 2018 at 13:08
• @ChrisH in fact I estimated that the density of the drink must be around 1.05 kg/l so in 100 ml of product there must be around 8.4 grams of sugar. Commented Oct 25, 2018 at 13:11
• that 7,9% is not content of juice in drink but amount of concetrate in the "juice" after turning it into solution. Commented Oct 25, 2018 at 15:01