Looks like a pretty good beer.
From the 1908 book, American handy-book of the brewing, malting and auxiliary trades By Robert Wahl, Max Henius.
CALIFORNIA STEAM BEER.
This beer is largely consumed throughout the state of California. It is called steam beer on account of its high effervescing properties and the amount of pressure (”steam”) it has in the packages.
The pressure ranges from 40 to 70 pounds in each trade package, according to the amount of Krausen added, ternperatures, and time it takes before being consumed and the distance it travels from saloon rack to faucet, etc. Usually SO to 60 pounds’ pressure is siifficient for general use.
More on California Common from that book here: