Calculating Sugar of Dessert Wine

[Resonant11]

Hello all, I'm making a dessert wine this fall, so I bought a bottle from a nearby vineyard to get a feel for how they should taste. Is there a way to measure the sugar content of a finished fortified wine? Is it as simple as taking a reading with a hydrometer or refractometer? I'd rather use a refractometer, but I could not find specifics on correcting for the alcohol content.

Thanks!

 

[winemaker81]

You're not necessarily going to get a useful reading from a hydrometer -- it measures the specific gravity, but doesn't give any indication of how much it was lowered by alcohol or raised by sugar.

Even if you can figure it out, it doesn't really help you. The "correct" amount of residual sugar in a wine is based upon a combination of the wine's ABV, body, and acid level. Every wine is different and you are best served by fine tuning the residual sugar by bench testing.

There is not an easy answer to "how much?" OTOH, bench testing is fun so you should enjoy the process.

 

[Resonant11]

Thanks for the reply, although I was afraid that was going to be the answer.

I just picked up smaller carboys, so I think trialing a couple different sugar levels for my wine should be doable. Bench testing it is! haha

 

[sour_grapes]

I am a little more sanguine than Bryan about the possibility of getting this value roughly correct. Since it is a commercial wine, you presumably know the ABV. If you spend some time with Fermcalc, you can probably home in on the combo of sugar and alcohol that gives you the known ABV and measured SG.

 

[BigDaveK]

The past couple months I've been playing with making "traditional" dessert wines. That means more fruit, a bit more acid, step feeding to crank up the ABV until the yeast die. I have three in bulk so I haven't back sweetened yet. I'm anticipating back sweetening to around 1.020 but I could be wrong. We'll see...

And @winemaker81 is so right, bench testing is fun! Do it when you know you won't have to drive for a while.