I have a branch of wolf river on a multi graft tree so I’m glad you mentioned this. I’m growing wolf river, wickson, and others on a tree in between 3 excellent seedlings which are intended to generate new apple seedlings. The idea is wolf river will make the new seedling apples much larger. Thanks for the tip on using the fruit. It’s been called a frost apple by many people meaning it’s best after a frost. Some of Wolf rivers attributes are briefly mentioned here http://adamapples.blogspot.com/2011/10/wolf-river-apple.html?m=1. On this site you will see many growers mention that it is a frost apple https://www.orangepippin.com/apples/wolf-river. You might like this old thread on best tasting apples Best tasting apples. A light frost is not the same as a freeze because freezes actually damage apples as stated in this article http://www.ehow.com/info_10040071_should-wait-until-freeze-before-picking-apples.html. Even frosts are not the key but rather the cooler weather around the time of the year when a light frost occurs.