The biggest challenge for cidermakers has always been the juice—it's heavy and takes up huge amounts of space. Because apples ripen only once a year, cidermakers end up having to deal with a year’s supply as it becomes available between September and the end of the year.
But in the 20th century, clever people figured a workaround: Concentrate the juice, store it, and then rehydrate and ferment as needed throughout the year. And that’s what large producers do.
It's instructive to understand the difference.