Wine 201: Sugar

How off-dry and sweet wines are made

“Is this wine dry? If not I don’t want it at all.”

“I don’t like sweet wine.”

Sentences people say that make me quite sad—because you’re missing out big time if you’re writing off all wines that are not completely dry! If someone says they don’t like sweet wine, I’m certain they just haven’t had a good one, or probably had it with the wrong kind of food.

What if you’re eating spicy food? Or something with high fat content? What if the dish itself has some fruitiness or sweetness? Or something super savory that could use some of that sweet and salty contrast? Or dessert, which you need to match the sweetness of?

We can go on forever because I’m a huge advocate for off-dry and sweet wines, but today let’s talk about the nerdy part of how they are made, in big concept buckets. And to dive into it, we first have to review how wine is made to begin with.

Alcoholic Fermentation

How wine is made is quite simple: you have yeast, which feeds on the sugar present in the grape juice, and uh… well, poops out alcohol and carbon dioxide. So yes, technically we are drinking (and enjoying) grape juice with yeast poop. Sorry for the information you didn’t want. Anyways.

Eventually, the food the yeasts eat to survive and continue producing alcohol runs out. So after all the sugar is gone in the grape juice, the yeast eventually starves and dies. And that, in a simplified way, is how we get our dry wines.

So the more sugar there is, the more food the yeast can eat, and the more alcohol they can produce. The more ripe the grapes are, the more sugars they have. This is also why wines from warmer regions have higher alcohol content.

Residual Sugar

But what if for some reason, the yeast can’t finish eating all the sugar that’s in the grape juice? There are two generic possibilities. One, the yeasts eat and make too much alcohol that they end up creating an environment they cannot survive themselves, and die. Two, the yeasts are stopped from eating more of the sugars in the grape juice, with interventions to kill off or take out from the juice. So the destiny of the yeasts in winemaking is, in one way or another, demise. But for a good cause. For us to have the adult juice we oh so love.

So after the yeasts are dead and are no longer eating and producing more alcohol, we are left with whatever sugar they didn’t get to, in the grape juice, still present. This is called the residual sugar—literally as the name suggests, it’s the remaining sugar. And since the liquid has some sugars left over in it… you got that right: the wine is sweeter.