When the grape samples come to the Winery, we test them for their sugar level, for the total acidity of the juice, and for the pH or the strength of the acidity. We do this in our lab using a titrator made by Mettler-Toledo.
In addition, we picked additional samples which we take to the Midwest Grape and Wine Industry Institute for “YAN testing.” YAN is yeast assimilable Nitrogen. The results of this testing tell us how much nutrients we should feed the juice as it undergoes fermentation. This is important because if we underfeed the yeast during fermentation, we can achieve a “stuck” fermentation that doesn’t finish and has to be restarted. If it has too much Nitrogen, the yeast will be stressed and will produce off-flavors that we then have to work to remove. We can’t measure YAN in our lab so we take several samples to the Midwest Grape and Wine Industry Institute at Iowa State University where they can do the measurements for a nominal price.
All of our equipment is set up and working. We will also move wine from our warehouse to the cellar so that we don’t have to take time to stock up during harvest.
