If you're sustaining from alcohol, the alcohol in the fish evaporates and doesn't remain in the fish. It also doesn't taste much like beer unless you use a very dark and strong beer. However, if you don't have beer, you can use carbonated water, cider, ginger-ale, champagne or other carbonated drinks. Keep in mind, some drinks will make the batter more sweet. This recipe was written for beer and may need to be adjusted if you don't have any. IMPORTANT NOTE: beer contains yeast, which aids in the batter remaining thin and not greasy. Substitute beer at your own risk!