I would recommend you finding a thread on here that's dedicated to capturing the esters and other flavors of English ales. Hopefully someone else can chime in on the name of it because I can't recall.
Just found it
https://www.homebrewtalk.com/showthread.php?t=221817
It's 62 pages long I think, I've gotten through enough to be able to apply some of it to an English dark mild using London ESB yeast. I followed a fermentation regimen called Fullers Temp Profile or something of that nature.
I believe I started the temp at 62 until fermentation was 2/3rds complete raised it to 68 for a d-rest and before fermentation was complete cooled temp back down. I think that's it. It's all in that thread anyway.
The idea is that the London ESB yeast will clean itself up if left at higher temps after the growth phase of the yeast, so by pitching cool and holding throughout the growth phase you are producing a cleaner ester profile, then ramping up to 68 will clean up some byproducts and then cooling the fermentation you will capture some of those fruity esters before the yeasts clean up.
Some Brewers have gone as far as getting the yeast off the yeast cake and then transferring to a keg to further prohibit the beer cleaning up. In the keg gelatin is employed to clear the beer while force carbing.
I brewed 4 English dark milds for a competition. First one was way too clean and was the only one that I employed a normal 2 week primary and 66/68 degree fermentation temp and just tasted like a light Porter. I then searched this forum for an answer and my next three batches were all fermented with the fullers schedule.
All three went from grain to glass in 6 days!!
I scored 37.5 at the competition, I think that's pretty good for a beer that takes 6 days to brew, didn't place but each judge noted the success of the ester profile. I made some mistakes with roasted malts that put it more into the area of Porter, maybe.
Good luck!
