My first batch of grape wine...Brix increase??

[Jean-Paul]

Hello everyone, im new to all this.
this is my first attempt at wine making.
I measured my Brix at must level then several times during fermentation. At first it looked good as the Brix was going down for 3 consecutive weeks then suddenly when i have no more sign of fermentation my Brix read a dramatic increase and became 9 (didnt take pics). But the wine tastes good... All this is making me go crazy...what went wrong? what is this?

 

[cmason1957]

If you use a refractometer in the presence of alcohol, it will read high and you have to correct for it. Your hydrometer is the better tool to use once fermentation starts. Here is a link to a spreadsheet, which will provide you an approximation, if you know the original brix reading.

https://www.morebeer.com/images/file.php?file_id=6158

For what it is worth, if you started at 23 Brix (1.091) and are now reading 9 Brix, you are not quite done, your apparent SG is 0.994.

 

[NorCal]

A hydrometer is to a winemaker as a tape measure is to a carpenter. If I could pick one tool, that is what I would choose. Refractometer is good to know when to pick grapes.

 

[Peter Gaulton]

Hi, yes the Brix reading from a refractometer will be distorted by the effect that alcohol has on the refractive index. The actual alcohol content can be determined if you take a reading from your refractometer and a hydrometer at the same time. There's no need to measure the specific gravity at the start with this method. A calculator is available from www.homewineprogram.com.