Pop popcorn in a popcorn popper, according to manufacturer's directions, into a very large bowl. Melt white candy melts in a microwave safe bowl, on 50% power, in 30 second intervals, stirring after each interval until melted and smooth. Pour melted white candy melts over popcorn and toss with a rubber spatula until evenly coated. Sprinkle lemon zest over popcorn and toss until evenly distributed.
Preheat oven to 275 degrees. Allow coated popcorn to dry at room temperature, about 10-15 minutes, then drizzle lemon juice over popcorn and toss well to evenly coat. Spread popcorn onto a rimmed cookie sheet and bake in preheated oven for 15 - 20 minutes until lightly golden. Allow popcorn to cool completely, store in an airtight container or large ziploc bag (note: this is best enjoyed the day it's made or one day following).