[evandy]

I brewed a beer with a new yeast a while ago.  It was an extract batch, so I don't have much control over mashing parameters.  Unfortunately, post-fermentation, the beer seems a little thin on the mouthfeel side.  Not a lot, but definitely somewhat watery.  Any suggestions on how to correct this?  I assume there's not much to do at this point with the current batch (in a keg, carbing).

[oceanselv]

With the exception of blending the beer with another batch, there is not much you can do at this point.  However, if you make the same recipe again, look at adding some dextrose to your steeping grains.  The yeast do not ferment the dextrose and the dextrose will add body and mouth feel to the beer.  For a typical 5 gallon batch you may want to consider adding 8 oz of dextrose.  I typically use cara-pils as my source of dextrose.

[Malticulous]

Add about a quarter pound of malto dextrin. I've seen it listed as 12% fermentable. In a keg it wont mater. Boil it in a small amount of water (or the beer), add it and close the lid before it foams over.

Things like this are best added late in the boil were it won't effect hop utilization. Don't add anything like this with the steeping grains or you will loose some more gravity to grain absorption.

[tschmidlin]

Don't add dextrose, it is corn sugar and is fully fermentable.  oceanselv means add dextrin.

What was the OG and FG of the beer?  What was the recipe?

[davidgzach]

Don't add dextrose, it is corn sugar and is fully fermentable.  oceanselv means add dextrin.

What was the OG and FG of the beer?  What was the recipe?

+1. 

[evandy]

The recipe was Jamil's Best Bitter.  I don't have OG and FG readings for my last few batches, but I have brewed the same recipe successfully a few times.  The only difference this time was changing from the London Ale yeast to the London ESB, so I expect that it's the yeast to blame.  Thanks for the thoughts on Malto-Dextrin.  I may try dosing a pint once it finishes carbing; if it helps I can scale up to a full keg.

[oceanselv]

Don't add dextrose, it is corn sugar and is fully fermentable.  oceanselv means add dextrin.

What was the OG and FG of the beer?  What was the recipe?

Oops you're correct.

[thomasbarnes]

You can also steep some crystal malt and add it to your wort. That will add body to your beer, since crystal malt has a fair percentage of dextrins in it. Any decent HB book will have instructions on how much to add and how to do it.

[jlap]

I would think that London ESB would give you more body not less...

[nateo]

A small amount of oak could help provide structuring tannins. Bitters should be served a bit warmer and flatter than other beers. Are you sure you haven't overcarbed it? I usually target about 1 vol of CO2 for my bitters, and serve them cool, not cold.