That's a lie.
Seriously, there should be no lye
in beer. In the process of cleaning brewpots, a cleaning agent (Sodium Hydroxide) can be used but it is thoroughly removed before any beer ingredients touches it.
An excerpt in Wikipedia explains any incidental connection:
"Commonly known as lye, sodium hydroxide (NaOH) and sometimes potassium hydroxide (KOH) is the caustic main ingredient of most heavy-duty cleaners like oven and drain cleaner. In its pure form, sodium hydroxide is very hazardous to skin and should only be used when wearing rubber gloves and goggle-type eye protection. Vinegar is useful for neutralizing sodium hydroxide that gets on your skin, but if sodium hydroxide gets in your eyes it could cause severe burns or blindness. Oven cleaner is an adequate substitute for any case that calls for sodium hydroxide. Brewers often scorch the bottoms of their brewpots, resulting in a black, burned wort area that is difficult to remove for fear of scouring a hole in the pot. The easiest solution is to apply a common brand of spray-on oven cleaner and allow it to dissolve the stain. After the burned-on area has been removed, it is important to thoroughly rinse the area of any residue from the oven cleaner. Because oven cleaners are caustic, rinsing with vinegar, a mild acid, will neutralize any remaining cleaner. Then a little detergent and water will suffice to remove any traces of the vinegar. Rinsing with vinegar is not usually necessary. It depends on the size of the stain and the amount of cleaner you use.
Sodium hydroxide is very corrosive to aluminum and brass. Copper is generally resistant to sodium hydroxide and stainless steel is only negatively affected by boiling hot solutions of sodium hydroxide (not recommended). Strong unbuffered solutions of NaOH should not be used to clean aluminum brewpots because the high pH causes the dissolution of the protective oxides, and a subsequent batch of beer might have a metallic taste."