Imagine going to university to study brewing, and for your dissertation you get to brew 5,000 litres of beer at one of Scotland's best breweries and then sell it to pubs and off-licenses around the country.

It might not be for everyone, but that's exactly what four postgraduate students from Edinburgh have just done.

Reade Huddleston, Sarah Brown, Richard Hamer and Sam Fleet have just completed the elite Natural Selection Brewing programme - a partnership between Heriot-Watt's Distilling and Brewing masters course and Edinburgh brewery Stewarts. Next week the four students launch their new beer, Bitter Descent, in the capital.

It's a beer that was developed over six months and in between technical lectures on hop isomerization and yeast attenuation. As project co-ordinator Sarah explains: "We worked through a number of different styles and prototypes before settling on a beer that matched our common vision - balance and drinkability."

Bitter Descent (5.1%) is an American extra special bitter, and, like the IPA, is another style of beer that began life in Britain but has evolved Stateside. American breweries took the traditional British bitter then chucked in a tonne of their local hops, and in Bitter Decent's case, the classic American C hops, Columbus, Centennial and Cascade, as well as Wilomet and Mosaic, were added.

Bitter Descent is an amber-coloured beer with a sweet and delicate pine and orange aroma. These flavours continue with tasting, which offers a much more rounded and complex experience that is superbly balanced with no one element dominating.

This beer changes as you move through it. First, fruity flavours, though these - like the aroma - are delicate, understated. Think muted passion fruit and mandarin. Then almost instantaneously, you're carried along by a sweet rich tea malt base that is soft, rounded, gentle. Toffee comes in towards the end, as does a slight sourness, as it eases into a medium dry and bitter finish that retains a juiciness that harks back to those first moments of the taste.

Bitter Descent is a cracker of a beer. It's subtle and clever, and should be sensibly enjoyed. Its success bodes well for the future of the NSB partnership, now in its fifth year.

Steve Stewart, founder of the Edinburgh brewery and a key driver of the NSB tie-up, says: "The Natural Selection programme gives brewing students practical experience in a commercial brewery, giving them invaluable experience and career opportunities.

"It's about innovation, education and brewing some great beer."

Bitter Descent launches Thursday, July 2nd at the New Amphion, Teviot Row House, Edinburgh.

www.naturalselectionbrewing.com

Five other great beers to enjoy, as picked by this year's Natural Selection Brewing team

Baby-faced Assassin by Roosters (6.1%)

Picked by Reade Huddleston, brewer, 24:

A big juicy hit of an IPA from this Yorkshire brewery. Flavours of summer stonefruits - peach and apricot - as well as tropical mango and grapefruit. Gives a crisp clean and bitter finish. Dangerously drinkable.

Jaipur India Pale Ale by Thornbridge (5.9%)

Picked by Sarah Brown, project coordinator, 25:

A hugely popular IPA and deservedly so. Big pungent citrus and resin aroma, with lush flavours of tangy grapefruit, orange, pine tree and sweet caramel malts make for a beautifully balanced beer with an enjoyably bitter finish.

Bloody 'Ell IPA by Beavertown (7.2%)

Picked by Richard Hamer, Sales, 23

Bloody 'Ell is a romp through the senses. With an aroma of mandarin, toffee and resin, this beer is bursting with flavour. Well balanced despite its strength, this is a hop-forward citrus-heavy IPA that's for savouring. Delicious.

Table Beer session IPA by The Kernel (3.3%)

Sam Fleet, marketing, 32:

An easy-drinking sesion IPA that's big on flavour and low on alcohol. The flavour changes with each batch, but you can expect these idiosyncratic brewers to serve up a vibrant fresh aroma and big zesty hop flavours with a light caramel malt base for a refreshing, easy-drinking beer.

Kokanee by Columbia Brewery (5%)

Professor Alex Speers, the NSB students' tutor and head of the International Centre of Brewing and Distilling.

A light pilsner style lager that dates from the mid 1950. As Professor Speers says: "I've never had a beer I didn't like, and there's a beer for all occasions, but this was my first beer, the beer I fell in love with."