Monday, October 25, 2010

The Not-So-Wrathful Grapes

October 2, 2010

With all the equipment bought and house mostly set up for wine making, it was finally time to pick up the grapes.  Thanks to the Sacramento Home Winemakers, I was able to get grapes (actually must, which is grapes that have been run through a crusher/stemmer to, well, crush and de-stem them) for ridiculously cheap--$0.55 per pound for Amador County grown zinfandel from Oakstone Winery.  I decided to start out with 250 lbs, since Chris said he did 125 lbs last year and it was kind of a waste of his time.  I was a bit apprehensive about getting so much the first time, but Chris convinced me to think big(ger).  Ultimately, I'm really glad I did.

To say I was nervous picking up the grapes would be an understatement.  Unfortunately for Chris, who graciously offered to drive his SUV out to Oakstone as there's no possible way 250 lbs of must would fit inside my Saturn (great gas mileage, but very little trunk space), I deal with stress by talking.  A lot.  About absolutely nothing at all.  And really really quickly.   It ended up working out well, though, as Chris apparently also deals with stress by talking.  We managed to fill the hour drive there and back with chatter about the various stages of wine making, with some politics and oohing and aahing over his little girl (who, to be fair, is one of the cutest toddlers I've ever seen) thrown in there for good measure.  We ended up having a very nice drive to the winery.  Unfortunately, as we were getting so little must, we were given a pickup time of 1:00 in the afternoon.  And the temperature that day happened to be about 90 degrees.  As any professional winemakers who happen to have stumbled onto this blog on a drunken evening to have a laugh knows, it's best to get grapes first thing in the morning, fresh from the vine and in much cooler temperatures.  The reason for this is that naturally occurring yeasts and even more naturally occurring bacteria live on grape skins and, given higher temperatures, yeast and bacteria will do what yeast and bacteria are born to do, which is convert the sugars in the grapes to nasty tasting by-products.  The grapes had been picked that morning, so they had been sitting around for hours in the hot sun.  Less than ideal, but hey, they were really cheap, and I didn't have to do the legwork to find them!

After a long and harrowing trip back down from the foothills, in which we only splashed a little bit of juice in the back of the car (t'was a flesh wound), I finally had the must in my house.  Brian and I started it out in our bathroom, in order to cool it down from the 90 degrees it was when it got there.  I then measured the Brix and pH, 2 numbers you'll be seeing a lot in the next couple of posts.  As a bit of background, Brix is a measure of the amount of dissolved solids in a liquid.  Since the vast majority of the solids dissolved in grape juice are sugars, the Brix number gives you the amount of sugar contained in the grape juice.  You measure this using a device known as a hydrometer, shown below: 
The hydrometer is dropped into a cylinder containing the liquid of interest, and the bulb on bottom weighs the hydrometer down until the density of the sugar causes it to float.  The level of the liquid at the top is measured on the scale on the neck, giving you the Brix, as shown below:
The other measurement is the pH, which is the amount of acid (specifically hydrogen ions) in a given substance.  The lower the pH, the more acid.  The scale runs from 1 (basically any lab-grade concentrated acid) to 14 (lye), and is a logarithmic scale, kind of like the Richter scale for earthquakes.  There are several ways to measure pH, but I chose to use this pH meter:

Basically, you just insert the electrode into your liquid of interest and wait for the reading to appear.  It cost about $250, but was so worth it, as I'll be measuring the pH all the freaking time.

Anyway, once I had the must in the bathroom, I measured the Brix and the pH.  Before I give you the numbers, I should tell you that, ideally, before adding the yeast (or "pitching," since apparently wine nerds like to at least pretend they can play sports) you want the Brix at 20-24 and the pH at or below 3.50.  This is basically the optimal range that the yeast works at, and the low pH has the added bonus of killing off all those other microorganims that are living on the grapes fresh from the field.

Now that the science is out of the way, I'll tell you that my Brix was 27.6 and pH was 4.35.  If your jaw isn't on the floor, then you knew as much about wine making as I did at the time.  The pH especially is insanely high, and really really bad (again, microorganisms, they love the sugars!).  Chris about had an aneurysm when he measured his.  To be fair, my pH meter was about 0.22 off, so the pH was only 4.13, but still seriously high.  The high Brix also meant that I needed to add a ton of distilled water to bring it down to a level that the yeast could handle.  This actually worked out for the best, as it allowed me to dilute the acid first instead of just adding it directly to the must.  I looked on the internet, and the gurus there said that I should add 1 gallon of water to lower the must by 1 degree of Brix.  By this logic, I determined that I should add about 3 gallons of water to optimize the Brix levels.  I started out by adding 2.5 gallons of water into which 9.5 tsps of tartaric acid (the acid of choice to lower pH in wine) had been dissolved to the must.  I did this at about 4:30 that afternoon, after allowing the must to cool for a bit.   I waited about 6 hours and measured the Brix at 24 (about right), but the pH at 3.74 (still a bit too high).  Therefore, I decided to add another 9 tsps of tartaric acid in half a gallon of water.  I then let it sit overnight to measure it in the morning.

And that, dear readers, is where we will stop this entry.  In the next exciting entry:  what is the Brix after adding all that water?  What's the pH?  Will I ever be able to pitch yeast, or will everyone be getting bottles of rancid grape juice in the spring?  Find out next time!!

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