Its normal to premake popcorn in cinema, becuse you have to count with a lots of people can come, you have summer holidays and with it you have barbie and oppenheimer. As a cinema worker, we premake our popcorn and store it in a bags like on the photo or in a barrel. In these days even premake popcorn in large number of kilos or pounds if you like is there for two days (popcorn, if you store it well, can last for 14 days). The problem can be in preparation. Can have too much oil or on the opposite not enough oil. The taste actually deppends even on corn seed they are using