Is fall frost beneficial for Brussels sprouts?

Frost exposure in Fall changes Brussels sprouts from somewhat bitter to buttery. The first harvest of sprouts I had before frost was tough and had a sharp taste. Now instead of springing them up to 28℉ nights, Brussels sprouts which have been exposed to frost are developing caramelized sugars that cheap, store-bought varieties lack in terms of flavour. There is timing and both science and art that will tell us we can expose them to the frost.

Using burlap is a way to prevent frost burn from incredibly cold snaps. I drape the burlap over stakes to avoid placing it directly on the plants. Keeping burlap away from the crop creates an air space between the plant and the burlap itself. I used this method during last December's polar vortex event. The plants covered with burlap produced 20 lbs of sprouts; the uncovered plants froze solid.

As the temperature begins to rise, it is best to harvest your vegetables in full sequence to maximize your frost cycles. I typically harvest the bottom sprouts first, giving the top sprouts a chance to sweeten further. This staggered harvest method has tripled my yield. Keep unwashed sprouts in a perforated bag (it does not need to be a classic produce bag) for six weeks at 32° Fahrenheit, the flavors will keep intensifying.

The maximum amount of sugar conversion happens roughly 72 hours after exposure to frost. The best way to test this is to use a refractometer. Under perfect conditions, Brix can go from 6% to the 12% range, and my biggest batch has been 14%, or the sweetness of a candy store. This biochemistry is why gardeners fight for that first frost and eagerly go in the garden before breakfast when it's cold outside.

Read the full article: How to Grow Brussels Sprouts: Pro Tips for Big Harvests