Improved red wine process efficiency and product quality through enhanced phenolic extraction by Controlled Phenolic Release (CPR) and Berry Pricking

Summary

Objectives

To determine if microwave processing and berry pricking are commercially viable alternatives to maceration by long skin contact time in red winemaking.

Background

Red wine colour and tannin are important quality parameters but rely on adequate extraction of pigments and other phenolic compounds from grape skin and seeds. Skin contact time, however, seriously constrains winery throughput.

Controlled Phenolic Release (CPR) is a novel process coupling microwave maceration with managed hold time. Laboratory-scale research on Pinot Noir and Shiraz fruit has shown CPR achieves rapid, effective, predictable extraction of red grape phenolics and thus more efficient winemaking. CPR was trialled on botrytis affected fruit and significantly reduced laccase activity. Berry Pricking is a rapid extraction process, used in traditional sloe gin production to enhance extraction of colour and flavour compounds from sloe berries. A prototype pricking device was effective for Pinot noir in semi-commercial trials during 2013.

CPR and Berry Pricking are expected to reduce skin contact time by approximately 60%, and rapid extraction and early press-off liberates tank space, meaning lower overall production costs and greater winery throughput.

Research approach

The project has a strong focus on industry engagement via working with winemaker collaborators to assess and optimise CPR (15kW-200kg/hour) and Berry Pricking for winemaking. The project will develop best practice methods, determine the compositional and sensory impacts of the new methods, build capacity in industry to undertake these new techniques and develop a business case to support uptake. More than 30 wines will be produced using lab scale equipment, more than 16 using pilot scale and at least 6 on a semi-commercial scale.

Industry benefit

The knowledge, protocols and devices generated by this project will allow winemakers to increase winery process efficiency and enhance red wine quality through more efficient methods to extract colour and tannin from grapes and to deal with Botrytis-affected fruit.