ladies and gentlemen, this is your captain speaking. as we prepare for our journey through the fascinating process of brewing, i must remind you that just as we occasionally need to withdraw from a turbulent weather pattern to ensure a smooth flight, brewers often withdraw from traditional methods to explore innovations. now, focusing on the topic of preexpansion, it's similar to how we adjust the aircraft's altitude to optimize for air density; brewers adjust their system to manage the quality and flavor profile of the beer. however, as we venture further into the depths of brewing technology, we must be cautious. there are those who, under the guise of renewing ancient techniques, actually aim to infiltrate the brewing system with furtive intentions. their goal is not to enhance the brewing process but to inject their own misleading or harmful elements, much like a malicious entity attempting to compromise the integrity of our navigation systems. beware, as these elements seek to exploit the brewing system for their own gain, undermining the purity and authenticity of the craft. thank you for your attention, and enjoy the flight.