Frances Jack

New product development for distilled spirits frequently involves experimental trials at the laboratory scale that attempt to replicate industrial-scale production processes. This process is time-consuming and limits the number of samples that can be analysed. The aim of the present study was to conduct laboratory-scale Scotch malt whisky production experiments to determine if samples taken from earlier in the production process, that is, directly after fermentation (wash stage) or after a single distillation (low wines stage), showed similar analytical differentiation compared to samples of fresh distillates (new make spirits). Napping, a rapid sensory method, was used to assess the impact on flavour characteristics while solid-phase microextraction (SPME) gas chromatography–mass spectrometry (GC–MS) was used to analyse volatile flavour congeners. Hierarchical Multiple Factor Analysis was used to compare the product maps from samples taken at each whisky production stage and revealed a pattern of differences across the samples that could be tracked through the process. Although the flavour descriptors and volatile congeners composition changed at each stage, there were only marginal changes in the differentiation between samples, resulting in the same sample groups being found in all analyses. RV coefficients >0.90 for all analytical comparisons and >0.74 overall showed that all product maps were highly similar to each other and showed the same overall differentiation between samples. These results indicate that the analysis of fermented malt whisky wash may provide sufficient information to proceed to larger-scale industry trials, saving time and allowing a greater number of parameters to be explored.

Electrocoagulation, an electrochemical technique used to remove heavy metals from wastewaters, was explored in relation to its potential to remove copper from distillery waste streams. An initial laboratory‐scale study demonstrated that copper in spent lees could be reduced by up to 95% using electrocoagulation. Copper could not be removed from caustic washwater, as passivation of the electrodes meant that no floc was formed. However, the washwaters could be treated if mixed with spent lees, with an 80% reduction in copper being obtained. The electrocoagulation system was scaled up and its performance evaluated in a trial at a large Scotch malt whisky distillery. Copper reductions of 88% were achieved at low power consumption (34 W h/m³), while at 112 W h/m³ residual copper levels were reduced by 96%. This trial was carried out at a flow rate of 1000 L/h, demonstrating that the technology could readily handle the volumes and flow rates required in practice. Both the capital and running costs of an electrocoagulation system are low, while the technique presents other advantages over the existing copper removal technologies currently in use in the distilled spirits sector. Copyright © 2014 The Institute of Brewing & Distilling

Sensory panels are used widely in the Scotch Whisky industry in a range of applications. Sensory data can play a key role in monitoring product quality or advancing flavour understanding. Therefore, the quality of this data must be high. Standard procedures for sensory evaluation outline requirements for experimental design, selection and training of panellists, and sensory room design. However, there are certain aspects of sample preparation and handling, specific to the assessment of whisky, which are not covered by these standards. This paper describes a programme of research aimed at examining these factors and their potential impact on sample condition. The results of this study have been collated, to produce guidelines for the preparation and handling of sensory samples in the Scotch Whisky industry. Following these guidelines should aid in the optimisation of sensory data quality.