In my pursuit of making an authentic British style ESB, I chose this yeast.  It’s known for some diacetyl production, which gives the butterscotch, nutty, or even bready quality to some classic british ales (although some of the malt depth is difficult to achieve).  Also, the strain is tolerant to 10% ABV, which is more than enough to handle a strong ESB.  Of course, with the attenuation levels given by Wyeast, you may end up with a touch of sweetness in the brew.  At any rate, here are the specifics for what I experience while using this yeast.

Yeast Type: Wyeast 1968 London ESB Yeast.

As the usual specifications for Wyeast and White Labs recommend, I allowed the 3-6 hours (I went 5) for the smack pack to expand and start yeast activation.

Yeast Uses: Because of its alcohol tolerance, this yeast has a multiplicity of uses.  Wyeast list anything from a Mild to an Old Ale to an IPA and even a Barley-Wine.  I feel this strain is especially conducive to making Barley Wines, ESBs, and IPAs, all of which are very nice with a residual amount of sweetness in their character.  Provided a rest is done at 64 degrees for short period, you should be able to reduce diacetyl levels, something I encouraged in my ESB.  Just remember that 67-71% attenuation will leave you with a residual sugar content, and you may consider finishing with a more thorough strain, like London Ale Yeast or even Irish, for a drier character.

Yeast Attenuation: As I said, 67-71% is the attenuation level given for this beer.  I fell right around the high range range with my O.G. being 1.070 (high end of an ESB) and my final being 1.012.  As you can see, I had some noticeable sweetness left in the beer, which was okay because of the higher alcohol for the style. I also pitched the second generation into another wort that I had made, and it easily achieved (and passed) the tolerance of 10% ABV.  This is a solid yeast, but I would recommend a starter with O.G. above 1.080.

Yeast Lag: I saw pressure building in the airlock within four hours of pitching the yeast.  By the fifth hour, the beer was slowly bubbling.  Between six to eight hours, I was seeing pretty active fermentation.  As always, depending on wort nutrition and yeast health, you may see slightly different results.  Listen to the manufacturer and wait 18 hours or so before re-pitching.  However, I expect that you will see results far before this.

Overall Performance: I want to note first of all that this was an ESB, which desires a particularly clean looking body.  This strain has a very high level of flocculation, so suspended particles really get dragged out.  I’ve found that lagering the beer for as little as a few days will aid with this dropping out.  Just remember that it may also collect diacetyl, too.  The yeast did what it was supposed to.  I did get quite a bit of apple tones, which are associated with particular acid productions.  Overall, it turned out to be a fruity ale with a balanced malt character.  I think this will be right up your alley if you choose to do some of the particular beers that I’ve mentioned above.