Sugar is killing us in so many ways, isn’t it? However, to have a winery without sweet wines is not feasible. Two questions emerge. Why do certain people prefer sweet wines and how can a winemaker provide sweet wines that do not compromise the health of the consumer? For some quick science, many people prefer sweeter wines due primarily to the number of taste buds on their tongues. So how do most American wineries make sweet wine? The industry standard for American wineries is to back-sweeten dry wines with sugar and or juice or juice concentrate. Following this method, the wine’s residual sugar becomes half glucose and half fructose since sucrose breaks down in acidic solutions into its two component parts, glucose, and fructose. And glucose is the problem. Our body needs glucose but our body’s requirement is considerably lower than what the typical American consumes daily. The overconsumption of glucose is linked to the vast majority of body diseases (think type 2 diabetes, inflammation, cancer’s food source). Additionally, the consumption of glucose and alcohol is disruptive to the Kreb’s Cycle, and, simply put, glucose and alcohol consumed together via disruption in the Kreb’s Cycle, we believe, is a strong attributor to hangovers.
At Turtle Run and most European wineries, sweet wine is obtained via arrested fermentation, a process in which we carefully monitor fermentation and filter the wines right when the residual sugar is where we want the taste to be. From 2009-2012, we conducted breakthrough research using an independent lab and discovered “sequential fermentation.” Yeasts convert sugars into heat, alcohol, and carbon dioxide but, as we learned, they do it in a unique order. If sugar is added, they will split the sugar molecule into one part glucose and one part fructose. Sugar, by the way, is not as an energy source for our bodies as sugar. It needs to be split by the body into one part glucose and one part fructose. In an analogy, think of glucose as a nice t-bone steak and fructose as over¬-cooked broccoli, broccoli with that nasty artificial orange cheese stuff further mushing up what once was a good veggie. Begrudgingly, I’ll eat the broccoli but the juicy steak looks more inviting, doesn’t it? In this analogy, think of the steak as glucose and the now nasty broccoli as fructose. I’m hungry so I’ll eat the broccoli (fructose) but I’ll eat it last. First, I’ll chow down on the steak (glucose), right? That is sequential fermentation. Yeast ferment fructose, which is how we get to dry wines, but they will always ferment glucose first. My “wild-ass theory” turned to the hypothesis is quite simple as to why yeasts ferment glucose before fructose – bang for the buck! As it turns out, fructose has 3 calories per gram and glucose 4 calories per gram. Think about that. If wineries simply monitor their fermentations closely and then chill and filter the wines when the residual sugar gets to the winemaker’s liking instead of taking dry wine and adding sugar, the consumer automatically enjoys wine with 25% fewer calories. Bingo! But wait, there’s more to this story
Fructose, as it turns out, is 2.2 times sweeter than glucose and 1.72 times sweeter than sugar (sucrose). Another calorie savings! At the same sweetness level as fructose, a winery would need to add 1.72 times the amount of sugar. For some very simplified math, our sweetest wine has about 3.5% residual sugar. Therefore, if a winery relies solely on back-sweetening with sugar, they would need to add 7% sugar, which is a more than doubling of the sugar calories in the wine.
But wait! Want to see how we can still find yet another source of sugar calories in most American wines? Let’s look at alcohol concentration and the perceptiveness of bitterness and bitter suppression by fructose, glucose and sucrose.
Alcohol is a bitter and for a certain segment of the population, they will do anything to avoid bitters. Sweetness and salt suppress bitterness. We conducted another exhaustive study between 2009 and 2012 to see what percent of alcohol in solution, tied to acid levels, could certain folks experience the bitter taste in alcohol. You bet we know that number. And the variants of that alcohol percentage due to someone’s perceptiveness of bitters.
Suffice it to say, wines that ferment to dryness with sugar back-added to sweeten them have more alcohol than controlled fermentation wines. Look at the alcohol percentage variation between Italian Moscato wine and American Moscato wines.
Well, we did the math. And about 500 folks participating in the study to keep our standard deviation in check. If a wine has 9.5% alcohol and 3.5% natural fructose via arrested fermentation, a wine with 12% alcohol needs, spot on, 12% added sugar to attain the same sweetness as the 9.5% alc / 3.5% RS (residual sugar) of an arrested fermentation wine. I could have some math fun right now – 3 calories per gram versus 4, plus 2.2 / 1.72 times sweeter, and 3.5% versus 12% in solution. Whew!
Finally, the arrested fermentation wines simply taste better than sugar-added wines. Fructose, to human taste is clean, refreshing and leaves behind no sugary, syrupy aftertaste. Glucose and sucrose, via the glucose, leaves that “sugary film” on the tongue. You know that sugar sensation. You finish something and you’re left with a “sugar coating” on your tongue. Fructose does not do that. High fructose corn syrup does, but that’s another discussion. Please don’t confuse fructose with nasty high fructose corn syrup.