Fermentation in Wine
Residual Sugar (RS) determines how quickly alcohol develops in the wine barrel, but there are points (somewhere around 10% and again around 11%, 12%, 13%, etc.) at which the curve flattens out some, and higher RS becomes moot for this purpose. The chart below (twelve wines with varying levels of RS barreled within minutes of each other) should give a fair idea of how this works. It is worth noting that these wines all hit 12% on the same day, even though there is quite a difference in speed at lower levels of alcohol.To put it simply, high RS is wonderful up front for speedy conversion to alcohol (up to about 10%), but it becomes increasingly less important the higher the level of alcohol desired.
| Starting RS | 10 May, 1:26 PM | 10 May, 2:51 PM | 11 May, 3:52 PM | 13 May, 2:30 PM |
| 21.5 | 0% | .2% alc | 4.1% alc | 10.2% alc |
| 38.0 | 0% | .4% alc | 7.2% alc | 11.1% alc |
| 48.0 | 0% | .5% alc | 9.1% alc | 11.1% alc |
| 52.0 | 0% | .5% alc | 9.9% alc | 11.1% alc |
| 58.5 | 0% | .6% alc | 10.2% alc | 11.1% alc |
| 65.5 | 0% | .7% alc | 10.2% alc | 11.1% alc |
| 65.5 | 0% | .7% alc | 10.2% alc | 11.1% alc |
| 77.0 | 0% | .8% alc | 10.2% alc | 11.1% alc |
| 78.0 | 0% | .8% alc | 10.2% alc | 11.1% alc |
| 93.0 | 0% | .9% alc | 10.2% alc | 11.1% alc |
| 103.5 | 0% | 1.0% alc | 10.2% alc | 11.1% alc |
| 115.0 | 0% | 1.2% alc | 10.2% alc | 11.1% alc |
Images
These are just pictures to document the information above. These are the same twelve wines placed in the same order in each picture. Again, the wines were all barreled within a few minutes of each other, and the first image was taken immediately after (hence 0% alcohol).
