Some Like it Hot - Macedonia's wine growing climate
Posted on Mon 13th Jul 2015 at 14:50
Macedonia is a country with a distinctly warm climate. Officially described as transitional from Mediterranean to continental, it typically has around 270 days of sunshine every year.
Summer temperatures can easily reach over 40°C during the day, along with warm nights too, which brings a number of viticultural challenges. Rainfall is also low, especially in the main wine areas (just 400mm is typical for Tikveš where more than 80% of the vineyards are located) and mostly falls in winter outside the growing season.
This has both pros and cons – a dry summer means little pressure from fungal diseases, so very little need for spraying. Macedonian producers claim to need just 1-4 vine treatments per year compared to 12 to 15 in a damper maritime climate like Bordeaux. Irrigation is pretty much essential here for anyone wanting to produce quality wine – drought-stressed vines tend to shut down, and stop photosynthesis, causing green unripe flavours in spite of the sunshine. There is an artificial lake in the region built in 1965, with concrete irrigation channels to take water to where it is needed. Flood irrigation is most common, but where producers have the money, investments are going into drip irrigation. This can save up to 65% of the water requirement, getting water to exactly where it is needed and avoiding wasteful evaporation.
For producers like Stobi, where winemaker Dane Jovanov has studied drought stress, drip irrigation is the way forward and it allows him to experiment with techniques like partial rootzone drying too (here vines are watered on one side of a row to avoid excessive drought stress, but left dry on the other side to bring the benefits of a little bit of a struggle to encourage smaller berries and deeper roots). Luckily as Macedonia is a candidate country for EU membership, there are support funds (such as IPARD) available that can subsidise these investments. Acid levels drop naturally as grapes ripen, but warm night time temperatures mean that malic acid drops particularly quickly as it is used up as the vines respire. This means producers usually need to adjust acidity to keep correct pH and acid balance in the wine. Macedonia is in the EU’s zone III C-b, allowing acidification but not enrichment. Focussing on local grapes helps too as varieties like Vranec and Žilavka have been selected over centuries to suit local growing conditions.
There’s always plenty of sugar here due to the warmth and if anything alcohol levels can go too high – sugar accumulates with temperature while flavour ripeness goes with sunshine hours. This isn’t helped by the local tendency for growers to pick too late and here producers like Stobi with their own vineyards have an advantage in total control over the harvest. Other concerns include sunburn on the fruit so careful canopy management is essential: leaving taller canopies and only leaf plucking from the fruit zone on east side of the vine to allow some natural sun shade. Another technique being tested in Macedonia is the use of netting – this is expensive but reduces sun exposure by 8-12% and canopy temperature by 3-5°C, and also protects the vines from the dramatic destruction of a summer hailstorm. Some vineyards lost 28% of their crop last year due to hail. Producers in Macedonia are already all too aware of the challenges of growing good grapes in a warm climate, but continuing research should enable them to cope and adapt as global warming takes hold. Written by Caroline Gilby; Master of Wine, for Signature Wines Ltd.