William called revolting southern red a sort of tea (8)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

Will called revolting southern red a sort of tea Buill (homophone of Will, also an abbreviated form of William) + DER S (S=southern + RED; “revolting” indicates vertical reversal); builders tea tends to be black and strong, often sugared, popular in construction work