Probably disgusting liquid barely resembling beer. I dumped a bunch of old ingredients together once and brew with bread yeast, just because I had some stuff getting ready to go bad. It did not turn out even close to drinkable. But if you catch that sourdough yeast with wort it might turn out differently, instead of using commercially available sourdough yeast. It is, after all, a lactobacillus culture. But I'm no scientist.