[Physics] How to make the bubbles in the soda drink last longer

everyday-lifefluid dynamicspressure

I would like to make the bubbles in my soda drink last longer.

For example, one good thing to do is to keep the bottle shut when you don't drink. But what else I can do? Should I try to minimize the surface between the drink and the air from the bottle? How about the surface of contact with the bottle? The bottle should be made of glass, or plastic? Does the temperature matter? Should I keep the bottle in a vertical position, to ensure more pressure at least for a part of it? Other, less realistic methods, are to keep it under pressure all the time, use a carbonating device, or drink it on the ocean floor. Or never open the bottle :), but assume that I want to open and drink from time to time.

Best Answer

There are various factors influencing how fast CO2 comes out of solution, but the two dominant ones are temperature and pressure.

Keeping the bottle closed allows the partial pressure of CO2 to build up above the liquid. Eventually a balance is reached so that there is no net releasing or dissolving of CO2 from/to the liquid. This is why soda lasts a long time between manufacture and when you first open the bottle. This is also why there is pressure in the bottle when you first open it. Keeping the bottle closed between sips will allow some pressure to build up, which will slow the rate of CO2 release from the liquid.

In general, gasses dissolve better in liquid at lower temperature. CO2 in water is no exception. Keeping the bottle cold will lower the partial pressure of the CO2, reducing the amount that bubbles out.

The roughness of the surface and the like are secondary effects at best. Probably the third strongest effect beyond pressure and temperature is mechanical disturbance. This allows a quicker interchange between the dissolved CO2 and the gas above the liquid. Since a recently-open bottle will probably not be in equilibrium, mechanical disturbance, like shaking, will cause CO2 to be released more quickly.