How the climate and soil affect Chianti Classico
Galestro
The impact of climate and soil on the Sangiovese grape, and therefore on Chianti Classico, is definitely a big deal. As you wander through Chianti, you'll discover all sorts of different soil types. And naturally, the shapes of the slopes and hills change from one valley to the next. For instance, wooded valleys or open basins have a huge effect on temperature and wind. Up and down, through twists and turns, again and again... and again.
You can't help but think of Chianti's gentle hills. These very hills are crucial for the climate and microclimate – as are the temperatures throughout the year. The varying structure and makeup of the soil is linked to the altitude and, ultimately, to the quality of the wines. In Chianti, this clearly defined region between Florence and Siena, you'll find a continental climate. On average, winters are cold (4 to 5 degrees Celsius), and summers are hot and dry (but usually not above 35 degrees Celsius), with moderate temperature swings during the day.
These fluctuations often come down to the different altitudes. The vineyards range from 200 to 600 meters above sea level, and in the Monti del Chianti (in the eastern part of the area), they even go up to over 800 meters. These different altitudes are naturally connected to varying soil conditions.
Different Soil Conditions
The (Almost) All-Important Soil
In the municipality of San Casciano Val di Pesa, you'll mostly find Galestro soils, while Greve in Chianti tends to have more clay-limestone (marl) soil, and along the ridge of the Monti del Chianti, you'll come across Macigno sandstone. Albarese soil is more common in the central and southern parts of the territory, and around Castelnuovo Berardenga, tuff rock is dominant. You'll actually find a lot of gravel and stones, especially Galestro, in all areas.
The Most Common Soil Types in Chianti
Galestro is the name for a type of shale rock that breaks down into smaller pieces due to weathering and especially frost.
Clay is a sediment or soil type made of super fine particles. Soils called 'clay' are mostly made up of clay minerals.
Limestone is a hard rock made of the mineral calcite (calcium carbonate). Plant roots can only make their way through its cracks.
Marl is a mix of limestone and clay.
Sandstone refers to a sedimentary rock made of sand particles, usually quartz.
Alberese is simply limestone – see above.
Tuff is a very calcareous soil that helps with better water drainage than most other types of limestone.
Gravel refers to a soil type, or rather, weathered rock where rock fragments make up the main part.
Rocks in Chianti
So, the mix of climate, soil, and altitude is the secret sauce for making top-notch wines in Chianti. Every winemaker around here will tell you all about how unique their soil and local microclimate are. More and more producers are really respecting this growing importance of the land and climate by farming sustainably and organically. They truly believe this helps their wines get even more unique character and personality. And in the end, that's great news for everyone who loves to enjoy a glass or two of Chianti Classico!