Why Are Root Vegetables Sweeter in Cold Weather?

Local grower Alex Weiser stopped by the 2013 Science & Food course discuss all things potatoes and parsnips. We heard all about Weiser's experimental plant varieties (Laker Baker, anyone?) and even learned why parsnips always taste just a little bit better in the winter. Check out the highlights: http://youtu.be/aAPEKKAGpPg