I had the same thing with a soy jar I kept near a fan. Two short burns and a chimney formed. What worked was a patience burn. I trimmed the wick shifted the candle to a quiet corner, and let it go until the top was liquid wall to wall. A little foil around the top sped it up, and I fed some of the side wax into the pool with a spoon once it softened. Since then I give the first burn the time it needs and never light unless I can keep it going at least an hour or two. Quick lights are the enemy with soy.
