Atomic was formed in Rugby in 2005, and generally produces pale hoppy beers. They have their own tied house in Rugby: The Victoria, which is a very friendly establishment, but take note that it does not open all day. They do brew a 9% beer Disaster which I have yet to try but is on my wish list.
Bradgy'r Bryn Cyf is a splendidly named brewery from Denbigh in Wales with a dual language website. This is another brewery formed in 2005. I must confess I have only had one of their beers, the simply named Bitter, but it was so good that the brewery deserves a mention. I need to find more of their beers!
Dark Star would be on many people's top ten list, and it was close for me. This brewery was formed in 1994 at The Evening Star, a fantastic real ale pub in Brighton, but has since relocated across the border into Ansty, West Sussex. They brew a huge range of beers, all of which are pretty decent. Their Hophead is renowned for huge hoppy flavours for only being 3.8%, and is a multi-award winner.
Durham is mostly famous for its strong bottled beers, although their cask beers are non too shabby. It was formed in 1994 in Bowburn, just outside Durham. Their 10% Temptation is a menacing Imperial Stout and the 8% Benedictus is a strong barley wine. A lot of their cask beers are very pale, and to prove this fact have the word "white" in their name. You can't go far wrong with any of these beers.
Grainstore does not appear to have a functioning website at the moment but that doesn't mean they don't know how to brew. It has been in operation since 1995 in Oakham, Rutland, and brews their own range of beers as well as those for the fictional Steamin Billy Brewery. Rutland Panther was Champion Mild of Britain in 2005, and won the overall Silver for CBOB. In my opinion all of their beers are good whether they be dark or light but their Ten Fifty does seem to have a cult following. They have their own pub at the brewery location, called The Old Plough.
Great Oakley was formed in 2005 in the village of that name in my home county of Northamptonshire. I am lucky enough to see their beers all the time, and they are all worthy of drinking if there are no scoops to be had. The pub I visit the most The Malt Shovel is their brewery tap even though it's a good 20 miles away, and features all of thir short run beers as well as the regular range. The 4.6% old ale Delapre Dark, originally a festival special has now become a permanent beer and has already started winning awards.
Harveys is the biggest and oldest concern on any of the lists, being formed in Lewes in 1790. However age is not an obstacle to brewing bloody good beer. Harveys beers have a distinctive taste. I always find peppery flavours in their bitters, especially Armada Ale which is without question one of my favourite English bitters. Sussex Best Bitter is also a wonderful beer which won overall silver in last year's CBOB competition. However it is their bottled Imperial Stout which has made them famous throughout the world. I must confess to not being the biggest fan of this beer, but plenty of people are.
Kilderkin is a brewery I have blogged about a couple of times previously. It is another brewery I have only had one beer from: Double, but that was a lovely beer, and I love the fact that they are trying Europen styles so much that they deserve a place on this list.
RCH is a brewery which just brews consistently well. They were formed in 1982 in Burnham-on-Sea, Somerset, but have since moved to West Hewish. They brew a number of beers and bottle some of their most well known. Beers to watch out for are Santa Fe, a 7.3% barley wine, and their porter, Old Slug, both quality beers.
Traquair is the final brewery on the list, and is included because of its wonderful strong bottled beers. Formed in 1965 in Innerleithen, Scotland, the vast majority of their produce goes onto bottles. House Ale, and Jacobite Ale are pretty commonly available and are both masterpieces. If you see them do not miss out.
That's it then. The twenty most exciting, most consistent British breweries around at the moment in my opinion. Let me know what you think.