Mrclean667
Junior
If you have both a hydrometer and a refractometer the original gravity can be determinedWithout knowing the OG, you're not going to calculate the ABV. You need original and final SG to do that. I've tried a vinometer, and agree with others they are a waste of money. There are methods where you boil a known sample size to eliminate the alcohol and measure the volume difference, but it's not anything I'd bother with.
Something to consider is the OG. If you started with an OG of 1.170 and are currently at 1.040, the EC-1118 is done. Meaning the ferment is done.
What is the overall volume of the must and how much sugar did you add? That will allow approximating the OG, with some degree of error. But close enough to figure out of the EC-1118 is maxed out.
A more likely scenario is the pH is too low, e.g., if it's below 2.9, yeast don't handle it well.
Depending on your volume, diluting the must may raise the pH enough to give the yeast a chance to work.
OGR = -400(FGH) + 2.512(FGR)+400.52
And to convert back to specific gravity
OGH = 0.00432(OGR)+0.9977
as derived from: OGR = 231.61(OGH-0.9977) reference (4)
Putting it all together:
OGH = -1.728(FGH) + 0.01085(FGR) + 2.728More useful would be the ABV level from final gravities as measured with a refractometer and hydrometer.
ABV = 131 (OGH-FGH) reference (5)
ABV = -357.4(FGH) + 1.421(FGR) + 357.4
Changes of 0.001 in the hydrometer reading can change the ABV by 0.5%. So it's important that this measurement is as accurate as possible. You way want to consider a precision range hydrometer such as the one at the bottom of this post.
Table 1, Original Gravity from Final Hydrometer and Refractometer Measurements.
Across the top, each column is for the final gravity as measured with a hydrometer.
Down the left each row is the final gravity as measure with a refractometer.
The cells in the middle are the calculated original gravity of the wort.
I am going to try this on beer I already have and know abv and also on the skeeter pee and see how accurate this is. There are a few YouTube videos of people who have used this calculation. There is also an app that if you plug the numbers into it is will calculate the and with those values.
https://apps.apple.com/us/app/fermcalc-winemaking-calculator/id6470156850