Grape Marc Spreading

What is Grape Marc and what do we do with it?

Grape Marc, or pomace, is the solid waste left after pressing the grapes. It is essentially organic material that has no further benefit for winemakers. During vintage, the grape marc is stored on a purpose-built concrete pad with high retaining walls and floor drainage.

The organic properties of grape marc have many uses/ It takes about 1.17 kilograms of grapes to produce a single 750 ml bottle of wine. Multiply this out over 1000’s of bottles and then ask where does the resultant mass of grape marc go?

Grape marc has long been used for stock feed and in vintages past we moved some of our grape marc to a local deer farm where it was used as a filler feed, supplemented with other nutrient -rich feeds.

Grape marc can be distilled to produce grape brandy or grappa, a traditional Italian spirit that is traditionally serves after dinner as a digestive.

Grape marc can also be used to produce artificial leather, used in beauty treatments, eg. grape seed scrubs, used as a substrate for traditional and hydroponic gardens, used to create energy – a single tonne of grape marc produces up to 400 litres of bioethanol and it can be used to fertilise the garden once it has composted down.

We compost grape marc adding saw dust and tree mulchings in a ratio of 1:1 with the grape marc and continually turn over the mix before spreading on to the vineyard. Composted grape marc encourages microbial activity protects the roots and improves water penetration and holding capacity. It is high in potassium and requires close monitoring.

This year we spread grape marc onto areas of one of our vineyards which is quite stony, and the vines struggle particularly in a hot, windy season. It’s a one-man job, loading the marc into the spreader and then delivering along two rows simultaneously.   

Image: uploads/2021_03/Marc_1.jpg
Image: uploads/2021_03/Marc_2.jpg

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