This is the start of a accumulation of notes I have made based on my learnings in the procces of making wine for 8 years now. I put it here toward the goal of being able to use my experience from prior years to make better wine in future years. Most of my data lies buried in my winemaker's notebooks for each year. Here are a few pages that have accumulations of data from multiple years.
The curve below shows the Brix to finished wine alcohol correspondence for a number of years of wines I have made. From 2006 notebook p. 13
These are my notes as I try to figure out what Mass and volume changes occur for each component from raw must through finished wine. It's way more complicated than you would think at first glance. I am interested in weights because the easiest parameter of the must aside from temperature to measure is the must weight which can be related to the density of the must if you know the volume. However, during fermentation the volume changes radically after every punchdown due to the CO2 pushing up the cap. The weight does not which makes it a more useful parameter to monitor. Temperature is an important parameter to monitor because the amount of tannin extracted from the skins depends strongly on the peak temperature of the ferment. 80-85F is the range I target but, note my grapes have lots of tannins.
Ripeness graph with a couple years of data. There are actually more years of data in the notebook now. We end up harvesting the first week of October plus or minus a couple weeks.
Advanced WineMaking Class - Paper I wrote on Napa Terroir
Last Updated 10/8/08