Flying Dog is always a great starting point. This Maryland brewery is bringing out a series of four Imperial IPAs, each with the same grist bill but heavily hopped with a different single hop variety. Where better to explore the profile of HBC-431, an experimental hop which hasn't even been named yet? At 10%, this imperial IPA is full-bodied with biscuity malts and a touch of alcohol sweetness, but the HBC-431 hop itself is the star of the show. Alongside fresh pine wood and a veritable fruit salad of mango, pineapple, melon and kiwi, this unusual new hop is earthy and spicy with a bitter lemon acidity.

Hop breeding is a long, involved process based on combining carefully chosen varieties to produce certain characteristics, but HBC-431's creation was reputedly somewhat of a fluke. The mother hop - of uncertain pedigree itself - was pollinated by random airborne pollen from an anonymous male hop. A happy accident, and one which has worked out well for Flying Dog's single hop series. Definitely one for fans of big IPAs who want to try something a little different.

Next up is another mega hoppy beer, but this is a million miles away from the sweet, tropical flavours of the last bottle. Dry, refreshing and mouth-puckeringly sour, Sur Citra was brewed by gypsy brewers To Øl at De Proef Brouwerij in Belgium. Sour pale ales are rapidly growing in popularity and Sur Citra is a great example of the style, with spritzy carbonation and notes of grapefruit, zesty lemon and unripe satsuma making it ideal drinking for a sunny afternoon.

Now here's one that may divide opinion: Rogue Sriracha Hot Stout Beer. Yes, you did hear me right! Known for brewing weird and wonderful beers such as Voodoo Doughnut Bacon Maple Ale and a beer brewed with beard yeast, Rogue has brewed up a one-off 5.7% stout using Huy Fong's Sriracha hot sauce. Fans of Sriracha will no doubt be dribbling at the thought of trying this spicy beer, which the brewery reckons is a great match for hot dogs, hamburgers and pizza.

Founded in 2013 by two American brewers, Edge Brewing in Barcelona was crowned Top New Brewer In The World 2014 by RateBeer.  At 6.6%, Hoptimista is dry-hopped twice to give it that quintessential citrus and pine character; robust and beautifully bitter, this bold American IPA was one of RateBeer's Top New Beers 2014. Having collaborated with other fantastic breweries such as Lervig and Northern Monk, it's clear that the beer scene has welcomed Edge with open arms, but what will they brew next? We can't wait to find out!

Last but by no means least, we just had to mention Founders Kentucky Breakfast Stout, or KBS as it's affectionately known. Each year the annual release fills people with excitement, and it's easy to see why.

Weighing in at a hefty 11.2%, this imperial stout is brewed with chocolate and coffee then aged in bourbon barrels for a year before being released to the public. Massive bourbon and vanilla notes waft from the glass, followed by thick dark chocolate, roasted coffee beans and a lingering hop bitterness throughout. Scoring 100 on both RateBeer and Beer Advocate, it's no surprise that KBS sold out almost immediately when we got a few cases in! We're looking forward to next year's batch already, but in the meantime it looks like we'll just have to get by on some of the other fantastic limited edition beers we've got in... It's a hard life, eh?