Pre-fermentation approaches to producing lower alcohol wines from Cabernet Sauvignon and Shiraz: Implications for wine quality based on chemical and sensory analysis

•Pre-fermentative juice substitution was performed for Cabernet Sauvignon and Shiraz.•Volatile and non-volatile compounds were analysed and sensory attributes were rated.•Shiraz colour and phenolic profiles were negatively impacted by juice substitution.•Sensory profiles of the wines differed depending on the substitution treatment.•An earlier harvest date could still be preferable for managing wine alcohol levels.