It seems that you might have a faulty assumption about the data.

Try using Data::Dumper to double-check that your data is as you think it is:

use strict;
use warnings;
use Data::Dumper;

my @bitter = `ssh serverlist 'ls -ltr'`
print Dumper(\@bitter);

...
[download]

I also notice that you aren't using any strictures... why not?