Embodiments of the present invention provide corks and cork systems that find particular use in connection with wireless spouts used for monitoring the amount of liquid poured from liquid containers. It is desirable to be able to use a wireless spout with various differently-sized bottle. Accordingly, the cork features provided can ease removal and replacement of the wireless spouts onto and off of variously sized bottles, and allow the same spout to be re-used with a differently sized bottle.