Pricking holes in your boerewors is a matter of preference. Some people prefer not to prick a good boerewors as the juices equal flavour. Others want the extra fat to drip into the fire, making the boerie fit for any diet. If you feel the constant need to prick those big fat bubbles on the wors, also consider looking at alternative butchers or types of boerewors that contains less fat to start with. Whilst some bubbles are normal, expected, and good; excessive fat bubbles in boerewors is not positive sign in terms of quality.