Originally Posted by Goyagon
So I was hoping someone here had more knowledge about this.
While I still don't qualify a little reading shows that aspartame decomposes into aspartic acid and phenylalanine(the 2 amino acids from which it is made) and methanol and that the process is accelerated by heat and high pH. Thus, conceptually, you could add the spice you intend to use to water, add some pickling lime, boil it, cool it and neutralize with phosphoric or lactic acid. This should leave the spice and the amino acids which yeast certainly can deal with. Aspartic acid is in Group A (taken up initially, synthesized later) and phenylalanine in Group B (taken up initially). Wort contains all sorts of amino acids and the small amounts involved here shouldn't be a problem. A taste test would reveal whether my concept is valid or not. If the mix is no longer sweet you have broken down the aspartame. The boil would drive off the methanol or most of it and the amount produced would be small anyway. As to the effect of heat on the spice itself - you'll find that out and that's something you would want to know as I assume you'd be adding this stuff to the kettle.