Poul Anderson 
Makeshift Rocket [EPUB ebook] 

Knud Axel Syrup, chief engineer of the spaceship Mercury Girl, sat and drank his favourite beer and thought about the coming war he was so anxious to avoid. For Grendel — the planetoid on which he was stranded — had been occupied by a band of fiery Irish revolutionaries. And once the rival Anglians discovered this, there response would be speedy and violent.Then, as Herr Syrup shook up a bottle of brew and let the foam shoot out of its top, he realised suddenly what could be done to get him off Grendel.And so came about a marvellous spaceship — built of beer kegs, bound by gunk, upholstered with pretzel boxes, and powered by the mighty reaction forces of malted brew!