Isle of Mull Dairy's website has nice section on making cheese (http://www.isleofmullcheese.co.uk/jalldridge/jaindex.htm) and a recipe and guidelines for making aged Feta (http://www.isleofmullcheese.co.uk/jalldridge/feta.htm) by very experienced James Alldridge.
Pages also posted in Library (https://cheeseforum.org/forum/index.php/topic,1242.0.html).