What is Chalk?
Chalk, a form of limestone, is a sedimentary porous rock, soft in texture and white in colour. It’s composed of the mineral calcite and was formed deep under the sea originally as tiny water-dwelling organisms, and creatures such as plankton, became compacted. In England, you’ll see chalk hills emerging from southern coastal areas in particular, just as they do right here in Sussex.
Why is Chalk Good for Sparkling Wine?
Drainage
Vines need a stable, healthy environment in which to grow, and chalk does so much hard work in providing this by preventing the soil from becoming waterlogged. Chalk has a high permeability, allowing water to progress easily through soil; this stops water building up and breeding the vine disease associated with waterlogged soil. It means the vine’s roots have access to the nutrients they need.
Consistent PH Levels
As chalk is a form of limestone, the PH levels in the soil are usually consistent, which is something the vines rely on to produce grapes with high acidity. It’s this perfect balance of acidity and sugars in the grapes that create delicious sparkling wines.
Climatic Regulation
Like many plants, a vine’s roots don’t appreciate changes in temperature, which is where chalky soil’s porosity proves to be, once again, very useful indeed. It helps to insulate the roots against harsh winter conditions, and also prevents them from overheating during hot summer days.
Sunlight Reflection
A south facing slope with light, chalky soil is music to a winemaker’s ears, and part of that is due to the capacity for sunlight to be reflected off the soil and back onto the vines. This reflected sunlight aids the photosynthesis process, ripening the grapes ready for harvest.
How can Vineyards Properly Manage Chalk Grassland?
Chalk grassland provides a home for a host of plants and wildlife, but there’s a danger of chalk grassland being consumed by other habitats, which is why protecting it is so important.
One way to do this is to promote the biodiversity within these areas, and facilitate wildflower corridors of between the vines to encourage key pollinators. With careful management, species that thrive on chalk grassland, such as the Adonis Blue Butterfly butterflies, can strengthen in numbers.
Here at Rathfinny, we work with Buglife, an invertebrate conservation trust, who have helped us identify the smaller creatures that are instrumental to the survival of this habitat around the vineyard, and on our chalk grassland banks in particular.
Taste what Sussex Chalk Downland can Achieve
As a grower-producer crafting wines on a single-site estate, each of our Sussex Sparkling vintages have been produced from grapes grown in this chalky Sussex soil.
To appreciate the landscape in which we grow and produce our wines, you can tour our vineyard, either with one of our expert guides, or via a self-led exploration. By doing this, you’ll be able to learn not only about the way we make our English Sparkling, but also the way we’re managing and protecting our precious chalk downland.
