California summers are extremely dry, and by July, the grasses on the hills surrounding Napa Valley dry out completely and turn a beautiful golden color. These golden hills, standing in contrast to the green vineyards, are the symbol of a Napa Valley summer—hence phrases like “golden blessing” and “The Golden State.”
But July of 2008 was different. On July 6, before the clock had even struck 10 a.m., the mercury easily passed 100°F, and by noon it finally recorded the fateful number: 105°F, about 40.6°C.
The asphalt roads crossing downtown Napa had turned into giant hot plates. They were not melting and running, but the smell of heated tar clung stickily to the air. The vicious heat haze rising from the road grotesquely distorted the peaceful vineyard scenery of Coombsville.
“This is an oven. Not a level any living creature can endure.”
Even with his straw hat pulled low, Warren was sweating nonstop as he muttered. Just as he said, the entirety of Napa Valley seemed trapped inside a gigantic convection oven. Humidity had dropped below 10%, and the dry hot wind seemed intent on evaporating every last drop of moisture from the earth.
In this heat wave, the grapevines had already entered a state of emergency. The stomata of the plants had shut tight to prevent moisture loss, which meant photosynthesis had stopped. The leaves began showing signs of leaf scorch, drying and curling brown from the tips in an effort not to surrender their moisture. If this continued for only a few more days, the acidity of the grapes would be completely destroyed, and all that would remain were fruit like flavorless sugar water.
“I agree completely.”
I wiped away the sweat running down my face and fanned myself with my hat before continuing.
“I can’t imagine what we would’ve done if we hadn’t given up the water rights and dug wells instead.”
Before my regression, heat waves had frequently come to California, so I had not thought much of it. Now I realized that this sort of heat wave had to be prepared for at all times, and I was convinced we had done the right thing by digging the wells.
Warren nodded, impressed.
“At the time, I thought it was absurd watching you hand over those water rights so easily, Master... but now that it’s come back around like this, I have nothing to say.”
To those who farm grapes in Napa Valley, water rights hold tremendous value. That is because water rights in the United States, especially in California, are extremely complex and strict.
First of all, the right to use river water is ranked according to who claimed it first. Once families who have held rights since the 1800s—Senior Rights—use up the water, wineries that came later may be unable to touch it, even if the river is flowing right in front of them.
So farms without water rights, or without many secured, have no choice but to worry about water for as long as they farm. In that situation, if a farm says it will hand over its water rights for free, it is only natural that everyone would think they had lost their minds.
“Even with water rights, water wasn’t always abundant.”
“That’s true, but... that doesn’t mean they’re something you give up easily.”
The more important issue here was that even if you had water rights, you could not use water however you pleased. The state government monitored river levels in real time, and during droughts, it could completely prohibit the withdrawal of river water. Farms that relied solely on the river would wither away then and there, which was why everyone had at least one well.
Moreover, Napa Valley has a typical Mediterranean climate, so in winter and spring, rain pours down and the rivers overflow—but that happens to be when grapevines do not need water. In summer and autumn, when water is actually needed, the Napa River exposes its bed or turns into a very thin stream.
And if a heat wave above 100°F hits on top of that? The river water would be busy evaporating, and if every farm stuck a straw into the river at the same time, the downstream section would dry up in no time.
That was not the end of it. The Napa River is an important habitat for coho salmon and rainbow trout, and the federal and state governments have stipulated that a minimum flow must be maintained so the fish can migrate. Therefore, if farmers use too much water and the level drops, the government immediately issues a ban on withdrawals—and it cannot be refused.
Although Napa Valley AVAs are expensive enough to cost hundreds of thousands of dollars per acre, landowners had to live with headaches beyond even that.
“Especially when you said you were going to drill wells in Coombsville... I really wondered if it was all right to spend money like that.”
There had already been plenty of criticism that we had paid a high price for land just to grow Merlot. Considering the land value alone, we ought to be growing Cabernet Sauvignon, but since we were growing Merlot instead, other people were bound to find it incomprehensible.
Then, when I said I would spend several hundred thousand dollars more to drill wells over 1,000 feet deep on this land, it was only natural for people to think I was throwing money away.
“Lapis Lazuli is the key benchmark that will set Astra Vale apart from other cult wines. This level of investment is only natural.”
“Yes. I agree with your thinking now, Master. Especially after going through a heat wave like this, I’m even more convinced. When I think about what would have happened if we’d trusted only in water rights and then gotten hit by this heat wave... it sends a chill down my spine.”
The same was true for Redwood, but Coombsville, located downstream of the Napa River, was even more vulnerable to heat waves. It is connected to San Pablo Bay, and when drought reduces the river flow, seawater flows backward into the river. The moment that salty water seeps into a vineyard, the grapevines die on the spot. But by drawing water from an aquifer 1,000 feet underground, we could safely protect the grapes even in a heat wave.
That was why Warren was so impressed.
“In any case, we drilled them at Redwood and the other farms too, so getting through the heat wave shouldn’t be too big a problem.”
At that moment, a manager approached and asked,
“We’ve finished connecting the sprinklers. Shall we begin?”
“Start them. Fix the water pressure at 80 psi and switch to fogging nozzles.”
“Understood.”
Soon after...
Kuuung—!
The massive drilling pump screamed back to life. Cold 13°C bedrock water that had not seen the light of the sun for tens of thousands of years surged up through the pipes from 1,000 feet below.
The manager activated the fine-spraying system installed throughout the farm. Instead of dropping thick droplets like ordinary sprinklers, the water passed through specially made nozzles, and the cold bedrock water sprayed out from them scattered into the air, instantly turning into a fine mist.
The reason we had not turned it on immediately after the heat wave arrived and had taken several days was that it had taken time to order and receive sprinklers capable of fine spraying.
“Can this really help us endure the heat wave?”
Warren asked, looking at it with fascination.
At the time, methods for dealing with heat waves in vineyards were not very effective.
At best, people installed shade cloths to cover the grape clusters so sunlight would not strike them directly, but this did not lower the ambient temperature itself. Night irrigation soaked the ground after sunset to lower soil temperature, but even that was not enough to stop the extreme transpiration during the day.
With canopy management, some grew the leaves thick to shade the grape clusters, but if there were too many leaves, the contradiction arose that the vines needed more water to feed them. In the worst cases, growers cut off the grape clusters early in order to save the vines.
This was why Napa Valley’s 2008 vintage had a low yield. Most farms had already been devastated by cold damage, and then a heat wave piled on top of it.
“Yes. Watch. It’ll change dramatically.”
Just as I said, after a little time passed, the surrounding air suddenly dropped in temperature and became refreshing.
“Ooh...”
It was the principle of evaporative cooling. The moment the 105-degree hot air met the fine 13-degree vapor, the vapor rapidly absorbed heat from its surroundings and evaporated. A mystical silver mist settled over the entire farm, and the temperature within the mist instantly fell to 80°F, about 27°C.
“This is practically magic, isn’t it?”
Warren stretched his hand into the mist, marveling. The air in the vineyard had become as cool as an air-conditioned room. The cold mist immediately lowered the surface temperature of the grapes.
The grapevines began to breathe again. Their stomata opened, and thanks to the lowered temperature, the loss of acidity due to respiration stopped. In particular, the delicate aroma precursors that were the essence of Astra Vale did not volatilize in the heat, but remained firmly locked inside the grape skins.
“It’s science rather than magic.”
If the water droplets are large, only the ground gets wet and the temperature does not drop very well. But if the particles are broken down into mist-like sizes of 10 to 50 μm, the contact area with the air is maximized, causing them to evaporate in an instant and lower the surrounding temperature by around 10 to 15°C.
California’s heat, in particular, is not like Korea’s sweltering, humid heat; it is a bone-dry heat that feels as if it is baking your skin. When the wind blows, it feels as though someone is pointing a hair dryer at your face. That is why this sort of mist evaporates even faster and its effect can be maximized.
In the early 2010s, this method was used experimentally in places such as Australia and Israel, but it was not used in earnest until the late 2010s. Combined with IoT technology, it began to spread in the form of smart farms where sensors detected the temperature and sprayed mist automatically.
All I had done was remove the automatic detection part and operate the mist manually.
“Then we can get through this summer with this as well.”
“Yes. Farming is so difficult...”
“You, the person getting through this ordeal better than anyone else in Napa, are saying it’s difficult? If someone heard you, they’d think you were mocking them and curse you out. You really are incredible, Master.”
Warren inhaled the now much fresher air and once again expressed his admiration.
---
At the foot of the Mayacamas Mountains, the symbol of Napa Valley, the office of Harlan Estate was filled with a suffocating silence unlike usual. The record-breaking heat wave of 105°F, or 40.6°C, had turned even the dense forests of the mountains a faded gray-green, as if they had been bleached.
Beyond the glass window, the road shimmered in the vicious heat haze, as if one were looking over a boiling cauldron.
“Bob, the water temperature?”
William Harlan asked in a low voice. Winemaker Bob Levy set down his PDA and opened his mouth with difficulty.
“88°F, about 31°C. As the Napa River’s water level has dropped, the sections where the flow has stopped are practically hot springs. If we spray this water through the sprinklers as is, the grape skins will boil and burst. At present, I see no way to preserve acidity until harvest.”
It was a report that made one’s chest tighten just listening to it. He had scattered enormous amounts of cash to George Bentley and the landowners because of water, monopolizing surface water rights, yet a heat wave like this had left him helpless.
Then the office door opened roughly, and his secretary entered with a deathly pale face.
“Chairman, Clark Anderson from the County Water Quality Department is here. But... he has brought agents from the State Water Resources Control Board, the SWRCB, and investigators from the National Oceanic and Atmospheric Administration, NOAA.”
Before she had even finished speaking, Clark Anderson, in a sweat-soaked shirt, stormed into the office with two men in suits. In their hands were thick administrative orders stamped with red seals.
“Mr. Harlan, you need to stop operating the river water intake pumps immediately.”
Perhaps because he was standing before William Harlan, Clark’s voice trembled, but it was firm. The enforcement officer from the SWRCB standing beside him set the documents on William’s desk as if throwing them down.
“This is an emergency order from Governor Arnold Schwarzenegger. The flow of the Napa River has fallen below the critical threshold. In order to prevent the destruction of the habitats of coho salmon and rainbow trout, all agricultural surface water withdrawal rights are hereby suspended as of this moment. If you violate this order, you will be immediately prosecuted for violating federal environmental law.”
William Harlan glanced at the documents on his desk and muttered under his breath.
“Damn it...”
210 A Song of Ice and Fire (3)
On the western hills of Napa Valley, Harlan Estate in the Mayacamas Mountains had turned into a battlefield because of the heat wave. The heat, which had surpassed 105°F, was heating the atmosphere and sealing the breathing pores of the grape leaves shut.
Under such circumstances, it was only natural that Harlan’s chief winemaker, Bob Levy, was standing in the middle of the vineyard with bloodshot eyes, as if he had not slept for days, sweating profusely. At his feet unfolded a bizarre sight rarely seen under normal circumstances. The deep green grapevines, the symbol of Harlan, had turned white like ghosts.
“Spray it more densely! You have to cover even the backs of the leaves completely!”
At Bob Levy’s instructions, dozens of workers were spraying a white liquid over the grapevines with high-pressure sprayers. It was kaolin clay, a special protectant made from kaolinite. This white clay powder formed a thin film over the leaves, reflecting powerful ultraviolet rays and lowering the surface temperature of the grapes—the most standard, yet desperate, defensive measure modern oenology could employ.
But the work demanded brutal labor. Since a rough mechanical spraying could not properly protect the stomata of the leaves, the workers had to wear masks to protect their lungs, sunglasses, and long-sleeved work clothes in the heat exceeding 40 degrees Celsius, painstakingly coating each vine one by one.
Workers collapsing from heatstroke appeared one after another, but Bob Levy could not stop. Harlan’s Cabernet Sauvignon was the pride of Napa, one that could not tolerate damage to even a single grape.
Because the labor costs were so high and the process of washing it off before harvest was so difficult, only extremely wealthy premium wineries could use this technique.
Next, Bob Levy tended to the canopy of a grapevine distorted by the scorching heat. Harlan’s technique did not stop at merely coating the surface with clay. He had already committed all manpower a week earlier to carry out strategic canopy reduction.
Ordinarily, the leaves would have to be kept lush for photosynthesis, but laughably, this year the clusters themselves had set in smaller numbers than in a normal year. The reason was frost damage.
Even though there were already fewer grape clusters, Bob boldly cut away an additional 30 percent. The more leaves there were, the more water loss through transpiration increased exponentially, and the vine itself could dry up and die.
“Reduce it to one cluster per shoot—no, even half a cluster! Cut away the clusters that have already lost moisture without hesitation!”
At Bob’s chilling shout, the workers’ shears moved faster. It was a pain like cutting away flesh. A single cluster of Harlan Estate’s Cabernet Sauvignon was worth hundreds of dollars on the market. But Bob Levy ordered forced thinning that would reduce this year’s yield to 40 percent of an ordinary year. It was a desperate choice, calculating the amount of water the roots could bear and concentrating the lifeline only on the very few premium clusters that could be saved.
“Bob, Harlan’s bottle count will be cut in half this year.”
A low, weighty voice sounded. It was William Harlan. He was dressed in a perfectly tailored suit as usual, but beads of sweat had formed on his forehead, and his eyes were filled with irritation. It made one wonder just how bad it had to be for him to refuse the air-conditioned indoors and come out under the blazing sun himself, bearing the weight of the heat wave with his entire body.
Bob Levy wiped his sweat and answered.
“Even if we produce only one hundred cases, we cannot release a wine whose Harlan structure has collapsed.”
“That’s right. What matters now is survival.”
Bob Levy knelt again and examined a single leaf. He was personally directing precision leaf positioning by hand, adjusting the angle of the leaves to create shade over the clusters. It was a severe perfectionism that machines could not achieve, something completed only at the fingertips of human hands.
But even after cutting away clusters and trimming leaves with the feeling of shaving bone from flesh, the heavens remained indifferent. The reading on the refractometer in Bob Levy’s hand had already soared to a dangerous level. It was not a normal rise in sugar content due to moisture drying out, but an abnormal phenomenon caused by concentration from heat.
“We’re putting out the immediate fire with canopy management and kaolin clay for now, but the fundamental problem hasn’t been solved. The river has been cut off, Chairman.”
Bob Levy raised an infrared thermometer and aimed it at a grape. The number that appeared on the screen was 103°F (39.5°C). It had reached the critical point at which the sugars inside the grape would burn and the acidity would collapse rapidly.
“Because of the state government’s water withdrawal ban, even running the pumps is impossible. At present, there’s no method except securing water tanker trucks from out of state.”
William Harlan stared at the dry riverbed in the distance. He had scattered an enormous amount of cash to buy water rights from George Bentley, but the government’s emergency administrative order had shut off the waterway, as if mocking the power of that capital.
“Money doesn’t matter. Whether from Texas or Oregon, bring in a hundred water tanker trucks if you have to. Rather than let the Harlan name be blemished, we must save the vines even if we have to cover the soil of this land with gold.”
“Understood. Still, it isn’t completely hopeless. California’s nights will allow the grapes to breathe.”
The greatest reason Napa Valley was a great wine region was that no matter how hot it became during the day, cold sea winds and fog would roll in at night. Even if daytime temperatures soared to 105°F (40°C), the temperature would drop sharply to around 15 to 18°C at night, allowing the vines to stop their metabolic activity and rest.
The reason this was important was that the malic acid inside the grapes was burned by the grapevine to obtain energy when temperatures were high, but when the temperature fell sufficiently at night, this combustion process stopped, preserving the acidity.
“And since the terrain is high...”
“That’s right. Harlan Estate is unquestionably Napa’s finest terroir. The terrain helps even during a heat wave.”
Since the temperature normally fell by about 0.6 to 1°C for every 100 meters of elevation, and mountain winds continued to blow, preventing heat from stagnating, it was still far more advantageous than other farms.
In any case, not long after William’s order was given, Harlan Estate transformed into a massive logistics base. Dozens of large water trucks that had crossed state lines climbed toward Harlan’s highlands one after another. Each time a truck came up, thousands of dollars in transport costs vanished, but William did not so much as blink.
But the heat of the highlands mocked the offensive of capital. The water the trucks diligently carried in during the day evaporated the moment it touched the ground, and Bob Levy eventually declared an all-out nighttime battle, their last resort.
That night, Harlan’s vineyard shone like a procession of enormous torches. Hundreds of workers roamed the fields with flashlights. Bob Levy personally put on boots and trudged through the muddy vineyard, inspecting every single drip irrigation nozzle.
“Calculate the evaporation rate! If the soil moisture sensor reading drops even by 0.1, report it immediately!”
Bob Levy knelt and grabbed a handful of soil. Even though night had fallen, the soil, still holding the heat of the day, remained hot. When he discovered the berry shrivelling that had begun to wrinkle the grapes, he bit his lip.
All these perfect, professional struggles—watering, applying white clay, installing shade cloth—were only barely keeping pace with the immense evaporation rate of nature.
---
While Napa Valley was suffering from the heat wave in this way, the pear farm in Lodi was also experiencing hell. Lower in elevation than Napa Valley and tucked deep inland, this place could not release the heat that had crossed the mountain range, forming a giant dome-shaped furnace.
Chloe, drenched in sweat, walked almost at a run between the pear saplings. Three-year-old pear trees. Like adolescents just before their coming-of-age ceremony, they were helpless before this brutal heat wave. Their leaves had been robbed of moisture and were blackening from the edges, and their young stems, which should have been taut, were shriveling as if all moisture had been drained from them like mummies.
“No, please...”
Chloe touched the leaves of a sapling with trembling hands. An ominous rustling sound came from them. Because of transpiration—the phenomenon in which plants release the water absorbed through their roots as water vapor through the stomata in their leaves—the leaves that had exceeded their critical point were giving up on survival and turning into fallen leaves. Just then, her cell phone vibrated loudly. It was Brian.
“Chloe, how’s the situation?”
At his worried voice, Chloe spoke in a voice that revealed her distress exactly as it was.
“Haa, Brian, the leaves are all burning. I checked the water coming out of the drip hoses, and it’s been heated by the sun until it’s as hot as hot spring water. If we give them this as it is, I think the roots will be boiled!”
“Chloe, calm down. Listen carefully to what I say from now on. Stop irrigation during the day immediately. The water inside the hoses exposed on the surface is hot, so right now, it’s no different from poison. Have the workers paint the lower parts of the pear tree trunks with white water-based paint immediately.”
“Paint? You’re telling me to paint in this situation?”
“Yes. When the sun is this hot, the powerful direct sunlight causes sunscald, where the trunk tissue is burned and becomes necrotic. Three-year-old saplings, in particular, have thin bark, so if they receive direct sunlight as they are, the cambium burns to death. The cambium is...”
“I know. It’s the layer of cells located just inside the bark. The key tissue that makes the tree grow thicker.”
“Ah... You really did study hard. Yes, anyway, for that reason, we have to reflect visible light and infrared rays with white paint to prevent the temperature of the sap from rising. Mix agricultural water-based paint with water at a one-to-one ratio and paint everything up to 50 centimeters from the ground.”
“Hold on!”
Chloe immediately picked up the radio. She had already grown accustomed to Brian’s system, but now, she had gone beyond simply doing as she was told; the principles were beginning to take shape three-dimensionally in her head.
“Management office! Take out all the white water-based paint in the warehouse! Grab sprayers and brushes and deploy to all sections. Paint the lower 50 centimeters of the sapling trunks thoroughly. We have to increase sunlight reflectivity!”
Chloe personally picked up a paint can and ran into the field. Bending over and painting under the blazing sun was agony, but her eyes scanned the saplings sharply.
“Brian, we’ve started painting. But what do we do about the leaf burn? If all the leaves fall, this year’s growth is over. It’ll be fatal for next year’s fruit set too, won’t it?”
“That’s right. So run the 300-meter deep well pump at full power now. Not the surface hoses—open the high-pressure mist lines we installed separately. Be careful! If the mist particles are too large, droplets will form on the leaves, and because of the lensing effect, the leaves could burn even more. To maximize evaporative cooling, you need to raise the water pressure.”
“Got it!”
Chloe ran to the pump room and adjusted the pressure gauge. When she raised it to 80 psi, the water spraying from the nozzles turned into a mist so fine it was almost invisible. In an instant, a white veil settled over the pear farm. The hot air collided with the cold mist so sharply that she almost imagined hearing a “chiiiik” sound.
“Chloe, one more thing. Increase the irrigation volume to three times the usual amount between 2 a.m. and 5 a.m. We have to lower the soil temperature around the roots below 20 degrees to secure the thermal inertia the trees need to endure the heat during the day. Let the trees rest during the day, and feed them water like crazy at night.”
“Understood. I should lower the nitrogen fertilizer concentration too, right? Their metabolism isn’t active right now, so if nitrogen goes in, ammonia toxicity could occur. Instead, I’ll raise the potassium content to strengthen the cell membranes and increase their osmotic regulation ability.”
A brief silence flowed from the other end of the phone. Then Brian’s satisfied laughter was heard.
“...Correct. Chloe, you’re a full-fledged expert now. Mix the potassium fertilizer very lightly as a foliar spray and apply it with the mist. Then the leaves’ stomatal regulation will improve.”
“Hmph, I’ve learned a thing or two too. If I’m going to be the girlfriend of Napa’s genius, this much is basic!”
Chloe hung up and stepped back into the field. Her whole body was covered in sweat and white paint, but her eyes shone brighter than ever. She touched each tree one by one, checking their condition.
“Hey, Jack! One of the nozzles in Sector 4 over there is clogged! I told you the particles can’t get too large. Replace it immediately!”
At her booming shout, even the veteran workers moved without a word of complaint. When she had first begun directing the workers on the farm, they had snorted, wondering what a pretty young lady could possibly know. But now they knew: she was more of an expert than anyone else here.
And so California’s hellish heat continued for two weeks, and astonishingly, in the aftermath of this heat wave, a miracle began to happen at Lapis Lazuli.