If you cast your mind back to the latest bcb meeting I brought along a best bitter. I overheard some conversation from down the table that there was a kind of unfermented wort character to the beer, even though fermentation had clearly taken place. I agree with that, and I don't want to get it again.

I was getting good advice from the people around me (tim and I think beerbulger?) about maybe trying a more characterful yeast next time, rather than Nottingham, which was used for that brew. Other than that can anybody think of a reason why it might have tasted like that? It's not a fault I've really heard about before other than when fermentation doesn't happen, which in this case it definitely had (hydrometer readings prove it). I'm thinking it might not have been just a choice of yeast issue because even lagers, where the yeast is very clean, taste, well, fermented.

Only things I can think of are poor temperature control and possibly not rinsing very well post sanitising the fermenter.

please help me better the best bitter that I brewed in bristol so I can bring a better bristol bitter that I brewed next time.

Nottingham is a good yeast for English style beers. While yeasts do impart a lot of flavour to a beer, generally, negative contributions are not directly from the choice of yeast, but from the way the fermentation is conducted.

Yeast does need some time to 'clean up' after itself and it does depend on the yeast. Mostly allowing 7-10 days will work. Many breweries cask sooner, but the beer is still working in the cask. Stressing the yeast will cause problems.

Read the manufactures sheet for the yeast you are using and try and stick to what is recommended.

I agree with roger, that the type of yeast used is not your issue.
I would recommend that you rehydrate your yeast in sterile water at around 35C. wait 15 minutes and pitch.ensure temps are within a few degrees of each other (rehydrated yeast and wort).
aerate your wort by shaking the fermenter vigorously prior to pitching
ferment at a constant temperature, until primary fermentation slows (judged by airlock activity), then ramp up by 1degree C every day for 2 or 3 days. leave in fermenter for a total of 2 weeks.

you are trying to create ideal conditions for your yeast
a healthy quantity (rehydration)
ideal temperature for attenuation and reducing off flavours
oxygen - for creating sterols which facilitate growth

cheers
steve

I'd guess temperature control, but trying to eliminate airborne: shaking/stirring/splashing to introduce more air into the wort when it is at its most vulnerable is a bad idea. I'd stick with a dried yeast such as Nottingham as luckily, according to Danstar, aeration is unnecessary as the yeast has been produced with adequate reserves. Nottingham is also kosher and GMO free (if anyone cares about that sort of thing).

PDF: Nottingham data sheet

Once the yeast gets going the theory is it should have more chance of overwhelming anything that drifts in later (when you're lifting the lid to have a peek!). Still, a plus of something like 1469 West Yorkshire is it forms a reassuring sticky protective mat on top of the beer that then drops away sometime after ten days.

It was me and Tim taking yeast (and b*****ks). Actually I didn't pick up anything unfermented - crystal finishes with a sweetness/ caramel. I thought it was a good bitter.

I think the conversation was along the lines of "It's good now. The next level probably needs the nuances that a particular yeast could bring." However note that there are as many opinions about yeast as there are brewers ... we were probably talking b*****ks!

Usually do lol!
The point about notty was I think it is a bit boring and strips flavour/bitterness and that there are more interesting dried yeasts available

Cheers all.