...
my $cookie_jar = HTTP::Cookies->new();
$mech->cookie_jar($cookie_jar);

my $file = 'valid_cookies.dat';

if (-f $file ) {
	    
    $cookie_jar->clear;
    $cookie_jar->load( $file );
}

...

# Add new valid cookie
my $key="INFO";
my $val="36D93C2F9E23D30EBD4B1F1A6D6E6871A5FA7184058AD675";
my $domain="foo.com";
my $maxage = 100000;

$cookie_jar->set_cookie($key, $val, $domain, $maxage);
$cookie_jar->save( $file );

$cookie_jar->clear;
$cookie_jar->load( $file );