April 08, 2012

Paper chromatography

Even though this year's paper chromatography has an unfortunate streak on it, I still love the pattern. I won't bore you with too much science, but essentially we use the chromatography process to see if there's still malic acid in the new 2011 wines. Malic acid is sharp tasting and in red wines we generally want it all converted to softer lactic acidity through the process of malolactic fermentation.

To test for malic acid, I dab a bit of wine from each barrel of pinot noir at the bottom of the chromatography paper. Using a developing solution, we see yellow marks appear to show the presence of various acids in the wine. On the right, midway up the paper, you can see a dark yellow spot. That's a sample of pure malic acidity, and it shows where malic acid appears on the paper. Moving to the left, you can see how there are no similar yellow spots in the same zone, meaning there's no malic acid in these samples. The exception is near the white streak, a touch of yellow from barrel 9 that presumably has some malic acid left.

I did this test a couple weeks back before a spring break trip, so I expect barrel 9 is done by now. I'll take a sample of that barrel to the lab to see for sure, then add a bit of sulfur to all the barrels and allow them to continue aging before bottling later this year.

I'm excited about how 2011 these wines are developing. They show nice acidic freshness, something I want to see more of in my wines. I'm particularly excited that this year I finally appear to have allowed the malolactic to happen successfully on its own. I've added a bit of malolactic bacteria to my wines in past years, after having a little trouble getting it to happen on its own. For whatever reason - art? perhaps. science? no. luck? definitely - this year it worked. These wines are truly nothing added, nothing taken away, pure. Just how I want them.


Michelle said...

This is beautiful! I was just looking for nice examples of 'everyday' applications for chromatography (I'm a science teacher). Do you mind if I use your image (with credit)?
thanks :)

Vincent Fritzsche said...

Yes, feel free to use the image. That sounds cool.