The Heat is On: Direct Impacts of a Warming Climate

Rising global temperatures are the most significant factor disrupting Merlot’s traditional growing patterns. The effects are multifaceted:

• Accelerated Ripening: Warmer conditions cause grapes to ripen more quickly. This often leads to a harvest that occurs weeks earlier than historical averages, as seen consistently in Bordeaux and Napa Valley. While this might seem beneficial, it disrupts the crucial balance. Sugars can skyrocket, leading to potentially higher alcohol levels, while the development of tannins and flavor compounds lags behind.
• Loss of Acidity: Heat accelerates the metabolic breakdown of malic and tartaric acids in the grape. The resulting wines can lack the fresh, vibrant acidity that provides structure and balance, tasting “flabby” or overly soft.
• Altered Flavor Profiles: The delicate, red-fruit and herbal notes characteristic of Merlot can be “cooked out” under intense heat and sun exposure. In their place, wines may exhibit over-ripe, jammy, or stewed fruit flavors, losing the variety’s signature elegance and nuance.

Beyond Temperature: Secondary Climatic Stressors

Climate change is not solely about heat. It also brings increased volatility, presenting new challenges for Merlot viticulture:

• Drought and Water Stress: Merlot has a relatively thin skin, making it more susceptible to water stress than thicker-skinned varieties like Cabernet Sauvignon. Prolonged drought can shut down the vine’s metabolic processes, halting ripening and leading to grapes with green, unripe flavors. In extreme cases, it can cause berry shrivel and significant yield loss.
• Extreme Weather Events: The increased frequency and intensity of hail, spring frosts, and wildfires pose a direct physical threat to vineyards. Smoke taint from wildfires, in particular, has become a catastrophic issue in regions like California, imparting undesirable smoky, ashy characters to the wine that are difficult to remediate.
• Altered Pest and Disease Pressure: Warmer, and in some places more humid, conditions can facilitate the spread of fungal diseases like mildew and allow new insect pests to thrive in regions previously too cold for them.

Adapting for the Future: The Viticultural Response

Faced with these challenges, winemakers and viticulturists are not standing idly by. A multi-pronged adaptation strategy is underway to safeguard the future of Merlot:

• Vineyard Management: Techniques such as planting cover crops to retain soil moisture, adjusting canopy management to provide more shade for the grape clusters (a practice known as “leafing”), and employing precision irrigation are becoming essential.
• Site Selection: There is a growing trend of planting Merlot in cooler, higher-altitude sites or on slopes with different aspects to find refuge from the peak heat of the day.
• Clonal Selection: Research is focused on developing and planting Merlot clones that are better suited to warmer conditions, with later ripening profiles or thicker skins for drought resilience.
• Blending and Style Shifts: Some producers are subtly altering their winemaking, picking earlier to preserve acidity, or increasing the proportion of Cabernet Franc in their blends to add freshness and structure.

Conclusion: An Uncertain Vintage for a Classic Grape

The story of Merlot in a changing climate is a powerful microcosm of the challenges facing global agriculture. The grape’s struggle to maintain its identity underscores the profound interconnectedness of our ecosystems. While human ingenuity and viticultural science are providing tools for adaptation, the trajectory of climate change will ultimately dictate the future character of one of the world’s most beloved wines. The question is no longer if climate change is affecting Merlot, but how the wine world will evolve to ensure its survival and continued expression in the decades to come.

OUR WINE REVIEW POLICY All wines that we taste and review are purchased at the full retail price.

Wine Reviewed Bartenura Moscato 2007 5.0 % alcohol about $ 10

Let’s start by quoting the marketing materials. Description : Classic Moscato with aromas of peach, table grape and apricot. Medium sweet with a slight effervescence and a low alcohol. There is a pleasant minerality that gives the wine structure. Soft and pleasing. Enjoy with spicy seafood dishes or serve with fruit custard desserts. Tasting Note : Pale straw yellow color; spicy apple, citrus and light pear aromas; sweet apple and pear flavors with balancing acidity, with peach and litchee notes on the finish.

And now for my review. At the first sips the wine was sweet, and I tasted some honey. Its first pairing was with a commercial barbecued chicken and a side of potatoes roasted in chicken fat and a light, tomatoey sauce. The wine’s acidity picked up with the chicken wings and breast, and the potatoes. The stronger tasting chicken leg choked out the wine. When paired with a mixed tomato salad containing basil the Moscato lost acidity but picked up some fruit. It became too sweet.

The next meal involved ground beef in ground semolina jackets and a sour sauce containing Swiss chard. This is a delicious Middle Eastern specialty known as Kube. The wine had honey and refreshing acidity, but this wasn’t a good way to do sweet and sour. The Moscato’s honey taste picked up with fresh strawberries.

My final meal was composed of a Portobello mushroom omelet accompanied by a spicy salsa containing tomato, onion, green pepper, cilantro and other ingredients. The wine struck me as bold and its honey taste was strong. Interestingly enough the salsa intensified the wine’s sweetness.

I finished this bottle with Matjes herring followed by two local cheeses. The results were basically the same, apples, honey, and light acidity. The herring brought out increased apple taste, and the Swiss cheese intensified the honey. An asiago cheese split the middle.

Final verdict. I will not buy this wine because while above price represents the American market, I had to pay considerably more. But at the American price I would definitely buy it, especially for those times that I want a sweet low-alcohol wine that tastes pretty good.