wp_query and functions.php

Hello! Im trying to understand why the following doesnt work as I’d like. When placed in a normal page template, it works perfectly fine, but when turning it into the function, it doesnt seem to return anything at all

function featuredevent() {

global $query_string;
parse_str( $query_string, $args );
$args['post_type'] = array( 'cocktails' );

query_posts( $args );
while ( have_posts() ) : the_post();

			$cocktailbrand = get_post_meta($post->ID,'cocktailbrand',TRUE);

endwhile; 

	return $cocktailbrand;

}

Any insight would be much appreciated. Thank you!!