"It was only half full," he confided afterwards. "And I sipped only a little." Nevertheless, in this election campaign, in which appearances seem to count a great deal more than content, he had done his duty, and was amply rewarded for his effort.
"Gerhard, Gerhard," thundered the chorus, clapping to the rhythm thumped out by Social Democrat cheerleaders at the front. "Kohl must go."
It was an impressive display of enthusiasm so deep in the heart of enemy territory. Augsburg was the mid-point on Mr Schroder's two-day tour of the conservative south. The town is prosperous, with relatively low unemployment and many Catholic churches. It is steeped in the arch-conservatism of Helmut Kohl's Bavarian sister-party, the Christian Social Union. If the aspiring chancellor can charm Augsburgers, he should not have much trouble with the rest of the country.
To reach them, Mr Schroder changed virtually none of the script he has been delivering up and down the country. The method and its effect is becoming apparent. The 45-minute off-the-cuff presentation is preceded by the same music and accompanied by the same videos.
The message stays the same, apart from minor improvisations. As the crisis in Russia heightened, references began to appear about Boris Yeltsin's chumminess - "meetings in the sauna" - with Mr Kohl.
Otherwise, the same buttons are pressed every time: unemployment, the government's pension cuts, the state of the health service and sick pay, and a pledge to improve youth training.
The applause comes raining in. The Social Democrats' spin doctors have decided to keep foreign relations, Europe and crime out of the presentation, because they are deemed to be of little interest to undecided voters.
With real issues getting little airing from either side, the elections of 27 September will be about presentation and personality. In presentation, the sleek SPD organisation, the Hollywoodesque rallies and the strategic coherence, are light years ahead of Chancellor Kohl's lumbering election machine. The battle of personalities is being decided now.
The Social Democrats are holding a steady lead of 4 to 5 points over the Christian Democrats, and their campaign is only now moving into top gear. The pollsters and many of his own supporters are beginning to give up on Mr Kohl.
With Bavaria out of the way, Mr Schroder's special train rolled into Baden-Wurttemberg, to bring the same message to the people of the Danube town of Ulm: "Spread the word - I want to win and I will win."