Measuring ABV of high alcohol beer/wine.

[ThePwnStick]

I've read that to make a high alcohol beer or wine, you add fermentable sugar when the hydrometer reading reaches 1.000, so the yeast don't get stressed out by all the sugar being added all at once. So how do you measure the ABV at the end of the fermentation if you can't just subtract the original potential alcohol from the final one?

 

[Bobby_M]

You just have to keep adding to the OG based on the known contribution of sugar you add over the entire process.

 

[ThePwnStick]

Is there a formula or a calculator online that'll let me do this?

 

[ThePwnStick]

So for example, if my OG is something like 1.070, and then when it gets to 1.010, I add enough sugar to make it go to 1.040, does that mean my OG is now 1.1?

 

[devilishprune]

Yes. That's exactly right.