How to burn a wood wick candle? Only burn candle for a maximum of 3 hours at once. Trim aspen woodwick to around 5mm before lighting and between each burn. Burns for up to 40 hours. The first burn is the most important because you have to give your veggie wax candle enough burning time to develop a melted wax pool that goes all the way to the edge of the glass jar on the first use.