From Brad Smith, PhD
"I feel it is important to address a number of myths about aluminum. First, aluminum pots are not linked to Alzheimer’s disease. A number of medical studies since the 1970′s have found zero link between Alzheimer’s and the use of aluminum. Keep in mind that every day you drink soda from aluminum cans (though most are lined) and eat food prepared in aluminum cookware – it is safe.
A second myth is that aluminum will react with acidic content of the wort and either add off flavors or eat away at your pot. This is also untrue – water has a pH of7.0, your wort has a pH of around 5.2, while spaghetti sauce can run as low as 4.6 and the most acidic diet sodas you drink run as low as 2.5. For comparison, battery acid has a pH of 1.0. Your wort is simply not acidic enough to react with your aluminum pot."