The climate here in Napa Valley is generally so agreeable that it’s easy to become complacent. We’ve come to expect warm, sunny days, cool, breezy nights and dry conditions during almost the entire growing season.
So, here’s 2011 giving us a reality check. Some growers are calling this their most challenging vintage ever. Why? Ill-timed rain.
In my last post we’d just come through three days of rain and busily stripped away leaves, improving the air flow, and got out the leaf blower to help dry things out. At that time, no more rain was predicted for at least another week - things looked pretty good.
Surprise! Another good rain last Monday, and this was a warm one. What does it mean?
If you look carefully at the photo, you’ll notice the hairline cracks in the skins and the soft, gray mold that has taken hold in the sweet juice. The warm rain created the perfect conditions to develop botrytis cinerea, which would be great if we were making dessert wine, but is not good at all for our Cabernet!
Bear with me while I digress for a moment because botrytis is actually a pretty interesting topic. Believe it or not, under the right conditions it’s known as the “noble rot”. If you’ve ever enjoyed a glass of Sauternes, Beerenauslese or Tokaji Aszu it’s the result of botrytis.
For white varieties, in particular Semillon, Sauvignon Blanc and Riesling, magical things can happen thanks to noble rot. It perforates the grape skins, causing dehydration, which ramps up the sugar and concentrates the flavor. Depending upon the situation, the grapes might come in as sweet as 40% sugar! For dry table wine we harvest at between about 21 and 26%.
So, the wine will be very sweet and, what’s more, the botrytis gives it an exquisite, honeyed character. Once you’ve had a sip of botrytized wine, you’ll never forget it!
However – noble rot isn't so noble for white varieties if the timing is wrong. Then, it's just ordinary gray rot or bunch rot. And when it attacks dark varieties, it makes the flavor go off and tends to turn the wine an unappealing gray color.
Botrytis can spread rather quickly, so our first priority is to remove clusters like the one you see here. The last couple of days have been quite warm and the air is very dry. If this continues over the next week or so, we should be home free. The 10-day forecast is dry, sunny weather - keep your fingers crossed!
Just look at these lovely, unadorned clusters!
The rain finally went away. We had about 2.5 inches over the last four days. But, it’s bright and sunny today, and the long-range forecast shows lots of warm weather, which is a very good thing.
As I mentioned before, it’s fortunate that we grow varieties that are resilient when faced with rain: Relatively tough-skinned Cabernet Sauvignon, Cabernet Franc and Petit Verdot. And, the fruit was very healthy going into the rain.
But, we don’t want to take anything for granted so job one, today, was to get out there and remove the leaves around the fruit zone to maximize the air flow around the clusters. You can see all the leaves on the ground around the vines. This helps the bunches to dry out more quickly. The downside is the birds have a really great view of their potential supper. We've already seen a few robins indulging...
We also used a very special, high-tech method to dry things out: A leaf blower! It works pretty well! The trick is to try to get the moisture inside the cluster dried out to avoid bunch rot.
Obviously, this would be an overwhelming job if we were big-time growers but for our small patch of Diamond Mountain it’s manageable and probably is a good calorie burner, too.
They're reading 23% sugar and we'll probably see a little bounce once they dry out. The acid, pH and tannins are coming along nicely. If the forecast is right we're set up for excellent flavor maturity at relatively low brix - the very thing we hope for.
Reports from around the valley indicate that most growers got their white varieties and most of the Pinot Noir in before the rain, so it may be that the dreaded rainfall won’t actually have a lot of impact. Let’s hope so!
No, you’re right – these aren’t grapes. There’s been a mad push to harvest in the valley because of predicted rainfall this week, starting today. Boxes and boxes of grapes going up and down the highway all weekend!
The only thing we can harvest at the moment are these very good looking tomatoes! Unlike grapes, if we don’t pick them they’ll fill up with water, the skins will split and rot will set in. So, it’s fresh tomatoes and basil for dinner tonight.
Believe me, if we were Chardonnay or Pinot Noir growers we’d be out there picking, too. Thin skinned varieties don’t handle rain very well. Rather than splitting they simply get bunch rot. The best thing those growers can do if the grapes aren’t ready for harvest is strip off all the leaves in the fruit zone to improve air circulation and pray for wind to dry things out. Or, they can pick right after the rain before the rot has a chance to develop, providing it’s not too muddy to get in.
The most affluent growers may hire helicopters to hover and dry things out but they’re the exception much more than the rule.
Fortunately, red Bordeaux varieties tend to be rot resistant. For instance, Cabernet Sauvignon has a good, thick skin and a loose cluster formation. And after such a mild summer the sugar’s not too high and there’s no raisining or skin damage from sunburn to make the grapes vulnerable.
The best antidote for rain is good weather and that’s supposed to return on Thursday so we’ve got our fingers crossed for our neighbors and, of course, for ourselves.
Just look at these tiny clusters! 2011 isn’t going to go down as a prolific vintage on Diamond Mountain! The good news is that small clusters and berries ripen more readily on a cool year like this one. We’ve had a good week of warm weather which is helping to move things along.
You’ve probably noticed that the term “balance” is something that comes up over and over when you’re talking about wine. Food, too, for that matter.
When wine is well balanced, you’re naturally attracted to it without necessarily knowing why – it just tastes good! So, in follow up to the last post on berry sampling let’s talk about the major components and why they’re important.
Sugar: The sugar provides the alcohol. We can figure that a little over half of the sugar we measure at harvest will wind up as alcohol in the finished wine. “Degrees brix” translates to percentage of sugar and we measure it with a prism-like instrument called a refractometer. It measures the soluable solids in the juice. About 90% of the soluable solids is sugar and the scale is calibrated accordingly.
Once we have our grape sample juiced and ready, we put a drop of the juice on the lense of the refractometer and presto - we’ve got the brix instantly. Most wine grapes are harvested between 20 and 26 degrees brix. If we harvest this Cabernet at 24% sugar we can expect to end up around 13% alcohol.
When you buy grapes at the grocery store they’re usually between 15 and 20%, so we’re working with extremely sweet, delicious fruit!
Alcohol gives wine a lot of its body, so we want a high enough sugar to make a full-bodied style satisfying and, for a delicate style, a low enough sugar to keep it light and crisp. On a cool year like this one the sugar is slow to come but, as I said, things are looking good and this Cabernet is 22% sugar – right on track.
Acid: Acid doesn’t sound attractive, does it? But, it’s so important. A good, solid acidity keeps the color bright, the flavors lively, makes the wine food friendly and helps it to age. Of course, too much is distracting because the wine is too tart. Too little and it’s flat. The main grape acids are tartaric andmalic and most wines fall between .5 and 1% acid (TA for titratable acidity), depending upon the growing region and the style.
pH: This is kind of like measuring the strength of the acidity and has a lot to do with the health and stability of the wine. In a warm climate we watch the pH carefully because if it gets too high it creates a friendly environment for bacteria and the wine browns easily. We shouldn’t have to worry about that this year.
On the pH scale 0 is acid, 7.0 is neutral and 14.0 is alkali. Most wines fall between 3.0 and 4.0. So, wine is higher in acid than almost any food you eat unless you enjoy fresh lemons, straight. Which means it’s automatically food friendly!
There’s rain in the forecast, so we hope the weather man is wrong. A little rain is fine – it gets the dust down. More than a sprinkle isn’t good news, but Cabernet has a thick, tough skin and a loose cluster formation (as you can see!) so it usually holds up pretty well. We'll see!
But it has a way to go. We’ve been berry-sampling this morning and just got back with our zip-loc bags full of grapes for tasting and analysis. We walk the vine rows and gather grapes from each section, or block, of the vineyard so we can gauge how quickly the grapes are ripening and when to finally harvest.
The main things that influence maturation are heat, light and soil moisture and we need to account for variations in the block. So, we take grapes from both sides of the vine. We eyeball the percentage of shaded clusters and gather accordingly. We like to take grapes from the top, bottom and middle of the cluster and also grapes from either side of the cluster. It’s smart to take berries from different parts of the vine, some from near the vine head and others further away... The sample should be as representative as possible because, ideally, we harvest the section once.
Then, it's back to the winery to taste, get a good look and see how we're stacking up in terms of sugar, acid and pH.
There are some visual cues that we’ve got awhile to go. As you see, the skin color is nice and deep, almost black - that's great - mature Cabernet grapes should look like tiny blueberries. You notice the green seeds? If we were to harvest now, very harsh, bitter tannins would be extracted from them into the wine. We’d like to see something more like Grapenuts cereal - brown and crunchy. And, as we walked the vineyard the stems of the clusters still look quite green. Those should brown up, too.
I wish you could see the flavors. You'll have to trust me that they're coming along nicely, leaving the early season vege character behind and developing the dark, berry-like flavors we love.
The brix, or percentage of sugar, is at 19.3%. With the nice, warm weather predicted for this week we're probably looking at mid October to harvest, much like last year.
Next post: Sugar, acid, pH: Why they're important
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