Ok, so I have implied but not said outright that I have been making wine for almost 30 years, but what I have also implied but not outright said is that there has been a break in that amateur winemaking career due to a divorce and moving across the country. You might notice some of my questions here, or posts elsewhere on the web were quite prolific, then I disappeared for a few years and I am back again.
Ok so this explains why I am asking this question. Below I am detailing my question.
Previously, I was sweetening my musts to target 1.100 in SG or a little more in order to get a decent ABV at 14-15%. However, for the last few weeks I have been using my hydrometer and noticing that 1.100 now corresponds to closer to 12.5% ABV. I have checked my old books and yes conversion tables ARE what I thought they were, but looking at conversion tables on the internet today show that 1.100 is between 12.3 and 12.7% ABV. What used to be universal appear to not be accurate and what is generally considered universal today doesn't match the past.
What gives? Are hydrometers and conversion tables entering in a calculated error to account for other solids in solution or what?