The soap bubble technique is when you use a solution of soap and water (kids’ bubble solution works great) and spray it onto potential gas leak locations, like joints and valves. Any leaking air will cause the solution to bubble up, making it easy to see where gas is escaping. If you try to use this method on its own, you might find yourself spraying soap all over the place without much luck, so it’s a smart idea to use this technique along with a gas leak detector. Once the detector has helped you narrow down your search area, a quick bubble test will let you pinpoint exactly where the problem is coming from. The only time soap bubbles don’t work well is if the leak is in a hard-to-reach location. In that case, a gas leak detector with a long, flexible probe is your best bet.