Each year, we bring our scale out and get it ready for weighing-in grapes. First, it has to be calibrated and certified by the State of Iowa and that happened on Wednesday. We also brought our hopper-elevator out from the warehouse and got it set up. We are doing our last shop clean-up and are cleaning out our macrobins.
The grapes have all gone through veraison and are now growing larger and sweeter. That means that the birds are going to discover them. We use kites that look like hawks to scare off the birds and are getting them up this week. We are also continuing to mow the grass strips between the rows.
Today and tomorrow, we are collecting grape samples to send to the Midwest Grape and Wine Institute for YAN testing. YAN is yeast assimilable nitrogen that the yeast can use in its metabolism. We want to see YAN numbers in a range so there is enough nitrogen but not too much. We can add a little, but we have to be careful because with too little or too much, the yeast will struggle in converting the sugar to alcohol. When they struggle, they produce off-flavors and aromas that we don’t like.
We are carefully updating our harvest estimate. We need grapes for our own production, and we also sell grapes to other wineries for their production. At this point, we are expecting to harvest about 105 tons. We will purchase about 5 tons to supplement what we grow and will sell about 30 tons that are excess to our needs.
We will get our trucks and tractors clean, shined up, and ready for harvest. We want our waste-water lagoons as low as possible so we’ll use the water for landscape irrigation. We will send samples for testing in accordance with Iowa DNR rules.
Finally, we are watching for fungus on the vines and will spray fungicide as needed.