Pitching Yeast

If that sounds suspiciously close to the old fashioned term “pitching woo”, it is entirely intentional. Adding yeast to crushed grapes is a labor of love — and there is just as much controversy over methodology as there is on the topic of love. Which yeast you add and how you do it is hotly debated with hundreds of variations. On the extreme end of the spectrum, if you are our Über Natural friend Cousin John, you don’t add yeast at all. (We’ll get to Cousin John later, along with his traditional winemaking methods which are currently threatening to recede back into pre-history.) First, let me tell you how we do it.

As you’ll remember from this post, we picked three of our four varietals in a panic harvest last Thursday just ahead of an early season rainstorm. Within an hour of leaving the field, all the grapes were run through the crusher/destemmer and the resulting slurry was pumped into our new steel fermentation tanks where it was treated with sulfite to kill any wild, stray yeasts. Then it sat for a few days just to make sure the job was done.

This is where we and Cousin John part ways. John believes in natural yeasts. But my mother always warned me about picking up strangers in bars or giving lifts to hitchhikers on the highway. So, as I chronicle here, Cousin John is risking getting tough, leather jacket wearing gang yeasts that are hanging out by a liquor store dealing Meth. We still value the worth of a college education. So we kick out the layabouts and introduce yeasts that have their doctorates from UC Davis — one of the premier universities in the world in oenology, viticulture and all things winemaking. (Seriously, even French winemakers are clamouring to get in.)

Okay, I kid Cousin John. But with love. We go through this clash of philosophy every year. The true test of who’s right will probably be keeping power and we haven’t gone head to head for enough years to where we can tell. Remind me in a few years and I’ll tell you whose Cabernet has stood the test of time and whose is an undrinkable vinegary mess. (Hint: ours will be the former.)

Then comes the time to pitch yeast. The key is to do everything you can to make these little guys happy. After all, you’re sending them out on a suicide mission. Literally. Once introduced to the grapes, yeast will gorge on the sugars in the grapes all while excreting alcohol. (I tried to explain this to DJ, one of the guys who works here. His reaction: “You mean alcohol is YEAST PISS!?” Yes, DJ, and I think I’ll make you my assistant for punchdown. It involves tasting.) Anyway, as the yeast are happily converting sugar to alcohol, they are changing their environment to the point where they are poisoning themselves with alcohol. Then it’s time for secondary fermentation. But that’s another story. For now let’s stick with what’s happening in primary fermentation, since it goes on for about a week to ten days.

Here is freshly crushed, destemmed Cabernet, sulfited to remove nasty delinquent yeasts and waiting for the college boys to arrive.

Here is the dry yeast waiting to be prepped for its mission.

Here is the yeast soaking in a warm bath of exactly 102 degrees. It wants to be warm, clean and comfy before being introduced to the grapes. Like good well brought up boys.

Here's the Cab a few days after the yeast was added. You can see that the action of the yeasts is expelling carbon dioxide and pushing the cap of skins up to the top of the tank.

This action is why the next week is pretty labor intensive for me. Two or three times a day, I have to check that the yeasts aren’t blowing the tops off the tanks with their exuberance. Then I have to “punch down” that cap to keep it hydrated. Red wine gets its color from juice contact with skin, so the skin cap needs to be pushed back down into the juice on a regular schedule, even as the yeasts, and their wine breath, are pushing them all to the top.

So that’s the lesson for today.

Oh, and this is Cousin John proudly advertising his Natural Yeast stance.

Ironically, that shirt is from Tablas Creek, which is in turn owned by one of the most illustrious winemaking outfits in the Rhone, Chateau de Beaucastel. (Our grapes are cuttings from Tablas Creek by way of Beaucastel.) So John further argues that we should be following their lead by using all natural yeasts. Maybe some day. I’ve heard that after years of shipping out the delinquent yeasts and introducing the upscale yeasts, you eventually build up a population of the good yeasts around your crushpad. It’s a yeast version of gentrification.

So we might use natural yeasts sometime in the future. When the neighborhood comes up.