Judging by the colour, looks like an ESB.
The 'secret recipe' bit made me laugh; the best brewers share their recipes. And there are only 3 types of beer anyway, when it comes down to it. A decent brewer could suss out the recipe pretty quick.
If they are REAL smart, they are using a proprietary yeast, which will not be easy to obtain or mimic. At least not until it gets put under a microscope ... or someone grabs the yeast from the trub. :)
Unfortunately, these types (English bitters) of beer are totally not in vogue in the US, and I doubt I will ever get to try it!!