Kinda. I know this answer is as painful to me as it is to you. Harvesting not quite ripe winter squash is common if freezing conditions are forecasted. The bottom line is squash, like watermelons, requires the natural ripening process (in sunlight), so the plant’s starchy carbohydrates turn into sugar and the creamy, nutty flesh. Sunlight is crucial to ripening butternut squash. I’m told that unripe butternut squash will have immature seeds, which will pull nutrients and sugars for several weeks to grow to maturity, which ultimately degrades the flesh and the flavor you want for your dishes, like this recipe for squash soup.