होते is a conjugation of होना (hona), but in the conditional tense (not in the "present indicative.") More on the conjugation of the verb होना www.verbix.com/webverbix/go.php?D1=47&T1=honaa&H1=147
The verbix link offers info on the conjunction of होना http://www.verbix.com/webverbix/go.php?D1=47&T1=honaa&H1=147
I think sometimes you CAN use it; other times you HAVE to use it.
A sentence CAN have it or not, but with it, it definitely stresses that something is "always that way". However I think this sentence is using it incorrectly since apples are NOT always red; they can be green, or yellow, or even bruised and brown - and the same can be argued about your dhood [milk]. :)