Results are in
Here is the Vinquiry report
Our analysis:
- 30 gallon barrel: 13 ppm; dropped 14 ppm from 27 ppm 8 weeks ago, or about 1.8 ppm per week.
- 15 gallon barrel: 23 ppm; dropped 11 ppm from 34 ppm 8 weeks ago, or about 1.4 ppm per week
- 13 gallon barrel: 23 ppm; dropped 11 ppm from 34 ppm 8 weeks ago, or about 1.4 ppm per week
I was expecting the smaller barrels to drop faster because of a higher surface area to volume ratio. I have always thought that it is the micro-oxygenation from the barrels is the cause for the free SO2 to drop. Something more to research!
In any case, we need to sulphite before bottling. We will:
- Rack the smaller barrels into a large white 30 gallon food grade bin, adding the sulphite early in the racking process which will mix it well. This way we avoid stirring the barrels and picking up any sediment. Sulphite the bottling wine to 40 ppm, or a 17 ppm addition.
- Bottle using a gravity feed out the of the 30 gallon bin.
- Rack the 30 gallon barrel into the smaller barrels, and add the sulphite to the smaller barrels at the same time. There will be 2 extra gallons, which we will bottle and use for topping the ’11 syrah, for which we have very little topping wine.
- Fill the 30 gallon barrel with water, citric acid, sulphite solution until we are ready to store it. We probably want to empty it long term, otherwise we will “use up” the oak on the storage solution.