eMail Us . Facebook . Twitter

Nov 17, 2017

Search our Site


Advanced Search

From Our Archives...


Wine X World Headquarters

© Copyright 1997 - 2015
X Publishing, Inc.

home  |   archives   |  about us  |  events  |  media kit  |  

Crush Explained
by Brendan Eliason
Magazine Issue: U.S. Vol. 3.6

Ah, what we do for love.

Winemaking's more of a passion than a job. The ultimate proof of this comes during crush. Your life and livelihood come right down to a three-month stretch, roughly September to November, when your grapes ripen, are picked and made into wine. If you do everything right -- and are lucky -- you end up with stellar-quality vino. If you screw up, or the wine gods are angry, you're screwed until next year. This is what fuels the intense, nervous energy that finds people spending 10 to 12 hours a day, six to seven days a week (and more), up to their armpits in grapejuice and forgetting to sleep.

It all starts innocently enough. In spring the grapevines emerge from dormancy and start growing green shoots. These shoots develop clusters of grapes that begin as green BBs, then change colors (a process called veraison), and finally reach the point of needing to be picked. This point is the start of crush.

The first real question of crush is when to harvest. What makes a grape cluster ready to pick? There are two basic philosophies of when to harvest; these two overlap to a great degree. (Warning: Both philosophies delve deeply into wine-geekdom. If techo-wine babble makes you queasy, as it does many people, skip ahead a couple of paragraphs.)

The first philosophy is the scientific point of view that looks at numbers. The three most important numbers are: Degrees Brix, pH and TA. Degrees Brix is the direct measurement of percent sugar by volume. Most winemakers look for a reading of about 24 degrees Brix (or 24 percent sugar). Easy. The next two numbers are loosely intertwined. TA stands for titratable acidity. It's the direct measurement of grams of acid in 100 ml of solution (i.e. juice). An average reading would be around .7 g/100 ml. Juice containing 1.0 would contain rip-the-enamel-off-your-teeth acid, and .5 or less would be so bland and boring that you'd rather crochet slippers for your dog while watching people fish. Then there's pH, also a measurement of acid, but not nearly as precise as TA. Generally you want a pH between 3.3 and 3.7. Usually when TA goes up, pH goes down. Variance changes greatly year-to-year, vineyard-to-vineyard, variety-to-variety.

The opposite of the numbers game is a much more traditional and simple approach -- tasting the grapes. This isn't rocket science. But there's a surprising degree of subtlety involved. Anyone who's worked with grapes for any period of time has a general picture of "the perfect cluster," though this image varies by individual. Hey, let's not forget, winemaking's still more of an art than a science, and not everyone agrees on art. For example, my perfect cluster of zinfandel looks so dark purple it's almost black. The skin of the grapes is just starting to get wrinkly, and there are a few shriveled raisins in the bunch. If I could get every cluster to look like this, I'd make the world's greatest red wine. Unfortunately, this rarely happens because agriculture relies on nature -- inconsistent nature.

In addition to sight, taste is invaluable. Once the grapes get into the general ballpark of ripeness, most winemakers or vineyard managers will start snacking on the fruit to see how the flavors develop. The change in taste can be amazing. Overnight, grapes can go from tasting like normal, boring table grapes to complex, flavorful taste-bombs. When all these elements come together it's time to pick.

There are two basic ways to pick. The first and most prevalent is to hire a crew of vineyard workers to hand-pick the grapes from the vine, fill up gondolas and deliver them to the winery. A new alternative to hand-picking is mechanical harvesting. This is accomplished by using an enormous machine that actually drives over the top of the grapevine rows in order to pick the grapes. As the harvester navigates the rows, the vines are funneled between two legs, where a set of wands shake, detaching the grapes from the vine. There's not a lot of finesse involved, but it's a highly efficient process. The two main drawbacks of mechanical harvesters are 1) they're expensive and not worth the money for most smaller vineyards, and 2) many winemakers are concerned that these machines bruise the grapes, which affects wine quality. Mechanical harvesters are very popular in countries such as Australia, which are abundant with sheep but short on manual labor for agriculture.

Since we're following zinfandel this year, let's examine the steps from vineyard to barrel.

The real fun begins once the grapes have been picked and delivered to the winery. At this point the zinfandel the grapes are first run through a crusher/destemmer machine. This is a fascinating piece of equipment that looks like a long cylinder on legs. Inside is a perforated tube that spins very fast. The perforations are large enough for the grapes to fit through but not the stems. So when you put whole clusters of grapes in the top of the machine, in a matter of seconds you get a pile of stems out of one side and chunky grape juice (now called must) out the other. (A small amount of stems is usually okay and most often unavoidable.) Should you be making red wine (yes, zinfandel is red!), you'd want the juice and the skins together, as you must keep the grapeskins in contact with the juice during fermentation. It's the skins that provide red wine with all of its color and most of its flavor. (The juice of almost all red wine grapes is white or slightly pink. Any guesses on how they make white zinfandel?)








Next, the must (juice and skins) is pumped from the crusher/destemmer into big white bins. Once in the bins, we add our yeast for fermentation. Some wineries let natural yeasts (which collect on the grapeskins during the growing season) do the fermenting instead of adding packaged yeast. But the general effect is basically the same. The yeast eats the sugar in the juice, creating heat, alcohol, carbon dioxide (C02) and sulfites. In our zin (as in all red wines) the heat and alcohol act together to break down the skins, adding color and flavor to the wine. The CO2 on the other hand presents an impediment to the extraction of the skins. As the grapes ferment and CO2 is released, the CO2 bubbles catch in the grape skins, floating them to the surface of the bin and forming a thick layer of skins called the cap. This becomes a problem because the skins are no longer in contact with the juice, so they can't be broken down.

The obvious solution to this problem is to periodically mix the juice and skins. There are two traditional ways of doing this. Some wineries (especially larger ones) simply pump the juice from the bottom of the tank and then back in, on top of the cap. This is called pumping over. It's simple and efficient. But some winemakers feel it doesn't mix the juice and skins thoroughly. The alternative to pumping over is to punch down. As you can tell, no creative geniuses were involved in naming these processes. Punching down involves using a long stick with a flat end (garden hoe, 2x4, custom made tool, etc.) to manually punch through the cap until the skins are fully mixed with the juice. While this effectively mixes the skins and juice, it is, as you can imagine, very time consuming and a pain in the ass.

Fermentation for our zin takes anywhere from one to three weeks (primarily depending on temperature). Once the juice "goes dry" (i.e., the yeast has converted all the sugar into alcohol), it's time to remove the wine and press the skins to extract all the remaining juice. So we drain the juice into a stainless steel tank and forklift the bin to the press.

There are many different types of wine presses, but all basically consist of two elements 1) pressure and 2) small holes. A very common type of press is a bladder press. This is composed of a hollow stainless steel cylinder with thousands of tiny slits. Inside the tube is an oversized inner tube and a screen over the slits. After filling the press, we spin it a couple times to evenly distribute the skins inside. Then we inflate the inner tube, which presses the grapes against the screen, yielding red wine through the slits but keeping in the skins. The wine is still cloudy (with yeast particles and some solids), but this will dissipate as the wine ages. From here our zin is pumped into barrels for aging.

Once all of your grapes have been harvested, fermented, pressed and barreled, and your equipment is cleaned up (more than half of winemaking is just cleaning stuff up), then you know that crush has officially come to an end. Now it's time to try and catch up on the hundreds of hours of missed sleep and to remember your kids' names. (Wait, I don't have any kids.) Anyway, all of this makes crush an exciting and intense experience.

On the down side, crush: 1) stains your hands and cloths black for three months, possibly forever; 2) requires working 30 or 40 consecutive days and 76 hours a week, causing you to look at your paycheck and wonder where the rest of the numbers went; 3) leaves you at the mercy of nature -- no two days are even remotely similar or vaguely predictable; 4) makes family and friends mere memories.

On the flip side, though, crush is often considered the best and most exciting time of year. After all: 1) you're actually getting paid to make wine! How cool is that? 2) your office consists of many acres of pristine vineyards -- a view tough to beat, 3) though nothing's predictable, you're certainly never bored, 4) sleep is for wimps and 5) you look good in purple! Not bad all in all.

Next issue we'll pick up our zin from the barrel, where it's been aging and settling.

E-Mail a Friend

Add Your Comment





Remember my personal information

Notify me of follow-up comments?

Please enter the word you see in the image below:

Back to top

home  |   archives   |  about us  |  events  |  media kit  |  

Sister Sites