Saturday, November 10, 2007

And now the end is near....

The end of harvest is upon us, so there is less to do out on the crush-pad, and there is now time to check in on things that have escaped our attention for the past few months. Here I am on the top of the 2006 barrels, preparing to sample from all of them so we can run some tests on them in the lab.

Bottling the 2006 wines will be upon us in January so we need to check in on them all and see where they all are in terms of pH, volatile acidity, titratable acidity and SO2. All of these numbers are important in terms of "barrel health", so to speak, and also impact blending decisions. For example, you may have a target pH of somewhere between 3.5 and 3.7 for your finished wine in bottle. If you have a couple of lots with pH's around 3.8 you want to find a home for them with lots that have pH's that are much lower.

Checking SO2 levels is a key test with bottling around the corner. SO2 is an important preservative that ensures the wine remains stable during its time in the bottle - i.e. no "in bottle" re-fermentation by any bad yeasts or bacterial spoilage. Most winemakers want S02 levels to be in the early thirties parts per million before bottling so running a free SO2 test in the lab will let us know how much more we need to add. Adding too much SO2 at once can also "shock" the wine (the wine hides its flavor and aromas) for a while so it is much more preferable to slowly raise SO2 levels reaching your target just before it goes into bottle.

Next week, I am going to be spending a lot of time in the lab helping out our oenologist so I will post more about the tests we run at Kosta Browne then!

1 comment:

Mark V Marino said...

Interesting you focus on
SO2 as it is important to stablity. However, I have heard wine makers rave about PH also. 30 parts per million is all you need for the SO2 but the Acidity can be a big discussion going back to brix at harvest as we know PH goes up with sugars and old school argues 3.5 is the high limit this goes along with the 23-25 brix school of wine making. More modern wine makers do not worry until 3.7 and fruit as high as 28-30 brix. The underlying concern is stabilty over time. Old schools argues longevity is compromised by PH over 3.5 and the wine will not age as well. this is the art in the mechanics of wine making! I wrote an article on it a few months back, "green versus black" (seeds)