The next time you taste a Japanese whisky – like Nikka Malt whisky – you will note the distinct fruity, estery flavors. As part of my studies at Heriot Watt University, I have come across some journal papers that point out the Japanese deliberately add Lactobacillus bacteria towards the end of the fermentation. These microbes feast on whatever may be left of the fermentable sugars in the fermenter plus they feast on the dead carcasses of yeast cells that have expired. What these microbes generate is lactic acid. According to the literature, this acid can alter the structure of fatty acids in the fermented wash to generate lactones plus they can combine with alcohol molecules to create esters. Net result – better mouthfeel and better flavor. I recently saw an add in a magazine for a Lallemand product called Sour Pitch which is Lactobacillus Plantarum microbes. This product is aimed at craft brewers seeking to make sour beers. I contacted Lallemand and they graciously provided me with some Sour Pitch. I have now completed 3 mashes using one of my Bourbon recipes. In one mash I added zero microbes. In the 2nd, I added a measured quantity after 84 hrs of fermentation and left the bacteria to grow in the fermenter for 24 more hours. In the 3rd, I let the same measured dose of bacteria grow for 48 more hours. I have now done A’Lembic pot distillation strip runs and spirit runs. I will be sending samples to Lallemend for GC analysis.We hope to be able to identify the presence of esters on the GC plots and we hope that the 48 hrs sample will have a greater ester profile. Stay tuned for the outcome….