Beer bottle aphrometer

I still bottle condition some of my homebrewed beers—especially bottles for sharing and for competition. One issue I sometimes have, especially with very strong and/or sour ales, is that the yeast in the bottle struggles to carbonate the beer, even after the addition of fresh yeast. An aphrometer is a device for monitoring the pressure inside a bottle as it develops. I can use such a device to tell if the beer is carbonating as it should. It is normally a mechanical pressure gauge that is connected to the bottle interior using a suitable seal such as a cork, modified crown cap, or some fancy mechanical clamp. They are generally expensive and normally designed for champagne bottles, which is why I designed my own. This design is basically a 3D-printed Grolsch-style stopper with a threaded hole through the middle. The 1/8” NPT threads allow me to attach a pressure gauge. A bent wire from a coat hanger is used to secure the stopper in place using other wire parts from the original swing-t