I'm sure that you are aware that esb is particular beer brewed by Fuller's. And the good thing is, that the Fuller's house yeast, which makes their beers a bit unique is available from multiple suppliers. However, many people, including myself, made the discovery that only one yeast supplier's yeast really seems to deliver that marmalade taste that the Fuller's beer is known for and that one is Imperial yeast a09 pub.I keep thinking I'll add a touch of Mandarina Bavaria to my next ESB-like recipe. Haven't tried it yet. Last brew I ran the 1968 yeast (Wyeast ESB) at 71 deg. F, hoping for fruity esters, but it didn't deliver. Looking at 1318 (London III) next. If that doesn't do it I'll probably start playing with a little bit of who-knows-what in a whirlpool addition. Mandarina Bavaria has my interest. Was hoping for something "berry" like but maybe tangerine would go well.