I've been making sushi for 38 years and I'm still learning. You have to consider the size and color of the ingredients how much salt and vinegar to use and how the seasons affect the fattiness of the fish.
My family makes these vinegars - out of everything from grapes to peaches and cherries. We go through the whole process with the giant vat and drainer label them and give them as Christmas presents.
Men are like wine - some turn to vinegar but the best improve with age.