A Crash Course in Winemaking, Part 1 of 2

Perhaps you’re new to the world of wine. Or maybe you’re an old pro bellying up to the tasting table on the reg. Either way, unless you spent a year at UC Davis, you may not know all the intricacies in the art of making wine. After all, it’s hard to find the courage to ask your friendly local somm, “so how do you make this stuff, anyway?” while pretending to recognize the notes of strawberry jam and cigar box in your glass of Cabernet.

On the surface, winemaking looks simple enough – toss some grape juice into a tank, then a barrel, then a bottle, and bam – you’ve got wine! Which is not…untrue (was legit how it was actually done for a very long time), but it turns out making good wine is a little more refined than that these days (some of you definitely learned this the hard way that one time you bought a wine-making kit online and crushed some table grapes from Safeway, sat on it for a year, and had nothing to show for it other than a truly awful bottle of the resulting vinegar, bummer).

Winemaking can most simply be summed up in the following steps: prune, grow, harvest, crush, ferment, punch down, press, barrel down, sample, sample, top, sample, sample, rack, bottle, repeat. Easy, right?

Before You Start

We could write an entire book on all the stuff you need to do before you even put roots in the ground. Lucky for you, this post is a blog and not a book, so we’re just gonna skim that part. Here’s the quick and dirty – you’ve got to find raw land, assess the soil and amend if necessary, assess the climate/microclimates and drainage, choose appropriate varietals and rootstock, orient the rows, decide spacing and trellis type, then finally plant. And the hardest part? You wait. It’ll be about 3 years before you have any fruit worth hanging onto. Don’t quit your day job to start a vineyard in Napa unless your stock of patience is plentiful.


Vines after harvest in fall with hills in the background in Chiles Valley, Napa County
Vines after harvest ready for pruning at Maxville Lakes Winery

Though what most of us see are swanky tasting rooms, vineyards are after all, farms. Winemakers spend 10 months every year growing grapes and 2 months making wine. All year long, vineyard staff give constant care and attention to making sure each vine gets the right water and sunlight and is protected from a whole host of pests and diseases. One of the most important yet under-appreciated aspects of winemaking is pruning (or the trimming back of dead vines and leaves after harvest season to increase growth and fruitfulness the next year). Over-prune and you get no grapes. Under-prune and, again, no grapes. Pruning is so important to a vine’s lifecycle that the Napa Valley Grapegrowers and the Napa Valley Farmworkers Foundation have an annual pruning contest where hundreds of vineyard professionals showcase their skills.


Vineyards on the dry hills in the Stags Leap District in Napa Valley
Vineyards at Cliff Lede in the Stags Leap District

At this point, winemakers have spent months coaxing those beautiful, picture-perfect clusters through bud break, fruit set, and veraison (the magical time where the grapes change color and ripen). They’ve managed the canopy, and by some miracle/mad skills, have managed to keep birds (and those pesky tourists) from eating all the precious grapes off the vines. Unlike most fruit, grapes don’t continue to ripen once picked (I’m looking at you, bananas and avocados), thus the decision of when to pick must be made at precisely the right moment. Winemakers will constantly sample grapes from around their vineyards, checking their pH and Brix (sugar measurement) until there’s a perfect balance between sugar, acid, and tannin. Your higher acid/low sugar content wines (usually sparkling and whites) are picked earlier. Sparkling wine producer, Mumm kicked off harvest this year on August 13th, and have been known to start as early as July (!!!), nearly three months before Napa red producers begin harvesting.


There are two harvest methods – hand harvest and mechanical harvest. While hand harvesting is backbreaking, labor-intensive work, it’s the preferred method for most winemakers (and the only option for many wineries whose vineyards grow along steep hillsides where mechanical harvesters can’t run). Harvest workers are experts in identifying clusters that are ripe and ready for harvest, as well as those that are damaged or underripe. Harvested clusters are then transported in shallow baskets or bins to avoid breaking the fragile skins (which can prematurely start fermentation – another reason harvest is often conducted overnight while temperatures are cooler).

White cubic grape harvest crates with equipment at Biale in Oak Knoll
Harvest equipment at Robert Biale Vineyards

Mechanical harvesting is exactly what it sounds like – machines are used to harvest the grapes from the vines. While faster and cheaper, machines also have a tendency to pull in what is affectionately called ‘material other than grapes’ or MOG – leaves, canes, sticks, trellis pieces, food wrappers and trash, and yes, the occasional…creature. Machines are also not as gentle as human harvesters, and are unable to distinguish unripe or rotten clusters. It should go without saying that the sorting table is *very* important for mechanically harvested grapes.


Old School
Crush machine with purple wine grape juice at Biale in Napa Valley
New School

At this point, the grapes are sorted, de-stemmed, and crushed – the process with which the juice is released from the berries. You may be familiar with the foot-stomp method of crushing (though the wine you buy these days definitely hasn’t had any feet in it, thank goodness). All grape juice is actually clear regardless of grape color. Skin contact with the juice imparts the color you see in the final product. For this reason, many winemakers will choose to skip the crush step going right to the press with whole clusters (which completely avoids any contact of juice with skins/stems by separating them immediately).

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