I live in Central Florida so I have been harvesting small pieces as needed to use throughout the winter. But yesterday I saw new shoots starting which surprised me since the rhizome with roots I ordered online last year didn't start to sprout until June. My plants died down in the fall but have remained mulched in their 25 gallon grow bags through our winter with just a few frosts.
I prefer the fresh root flavor to the dried powder so I want to keep it as “fresh” as possible. I’ve been sort of micro-grating it fresh and freezing it in ziplock quart bags squished flat so I can break off pieces as I need them. Since I also use it in smoothies I store small chunks (like the small pieces left when I micro-grate it) in the freezer since my smoothie blender pulverizes them along with my frozen fruit. I freeze whole ginger roots and grate as needed but I have much too much turmeric root from last year to do that with just a refrigerator/freezer. So I think that the grating is the best way to store. But my hand gets tired and my fingers yellow so I can't do too much at a time.
I might try dehydrating some thin slices to see if I like using the dried form as much as the frozen.
I am also about to try using my smoothie blender on the fresh and frozen small pieces to see if I can pulverize it enough to get the same product that I get from micro-grating.