As an experienced sommelier and brewer, I can confidently say that Star San does not need to dry completely. In fact, you should not let it dry. The key to using Star San effectively is to wet the surface thoroughly and then let it air dry.
One of the great things about Star San is that it does not require rinsing. Once you have applied it to the surface, whether it's a fermenting vessel, a keg, or any other brewing equipment, you simply let it sit and air dry. The contact time required for effective sanitization is usually about one minute.
The reason you should not let Star San dry completely is that it loses its sanitizing power once it dries. By keeping the surface wet with Star San for the appropriate contact time, you ensure that the sanitizer is working to kill any bacteria or other microorganisms present.
Now, you may be wondering about the foam that Star San produces. It is normal for Star San to create foam when it is mixed with water. Some brewers find the foam to be a bit messy, but there's no need to fear it. In fact, the foam can be beneficial in some cases, as it helps to reach all the nooks and crannies of your equipment, providing thorough sanitization.
However, if you prefer to minimize or eliminate the foam, there is a simple solution. You can use a spray bottle to apply the Star San solution instead of immersing your equipment in a bucket of the solution. This allows for more controlled application and reduces the amount of foam produced.
In my personal brewing experience, I have found the spray bottle method to be quite effective. It allows me to quickly and easily sanitize all the necessary equipment without excessive foam. Plus, it saves me from having to rinse everything afterwards.
But let's say you decide to do a full deluge and end up with some foam. Don't worry, it's not a big deal. The foam itself is not harmful or dangerous. You can simply let it dissipate naturally or wipe it away with a clean cloth. Just remember to keep the surface wet with Star San for the appropriate contact time, and you'll have a properly sanitized brewing environment.
Star San does not need to dry completely, and you should not let it dry. Wetting the surface with Star San for the appropriate contact time ensures effective sanitization. The foam produced by Star San is normal and can be controlled by using a spray bottle. If you end up with some foam, there's no need to fear, simply let it dissipate or wipe it away. Trust in Star San's sanitizing power and enjoy brewing without the worry of rinsing or drying.