Hop harvest: All in a day's work

Peering over the top of the mash tun, head brewer Roger Ryman exchanges worried looks with fellow brewer James Vincent. "That's an awful lot of hops," he says, gazing at the mounds of what look like misshapen Brussels sprouts covering the bottom of the huge wooden tub.

There is a long, silent pause - and I'm wondering whether I've just had a hand in creating St Austell's one and only brewing disaster - before the pair grin broadly and shrug their shoulders. "Oh well, it's an experiment," says Roger. I am, it appears, in the presence of two overgrown schoolboys who have landed "the best job in the world" - James' knee-length shorts only strengthen this image. You can throw in a bit of mad professor if you like for good measure. The pair - and in fact everyone I meet at the brewery - are totally and madly in love with beer: it really is the grown-up version of Charlie and the Chocolate Factory. And when Roger tells me that 90 per cent of the time it isn't this much fun, I just don't believe him.

But the concern about the quantity of hops used is real: we have just poured nine bags of the stuff into the mash tun. The tricky thing is, they are fresh hops - as opposed to the dry hops that are usually used - so you have to add roughly five times as much, which in the flesh starts to look a little scary. We're adding 100 kilos of fresh hops to make 50 brewers' barrels of beer in St Austell's first ever 'hop run'. If it works, it might not be the last.

St Austell has recently revived a tradition of introducing one-off seasonal cask ales - examples include Liquid Sunshine, Cockle Roaster, Wreckers, Tun 50 and Zingi Beer. The really popular beers might become year-rounders or get revisited. Tribute, for example, created by Roger in 1999, started out as a seasonal beer called Daylight Robbery. The name was poking fun at those businesses that hiked their prices in anticipation of an influx of tourists into Cornwall, wanting to witness the total eclipse of the sun. But as Roger says: "This wasn't a name to build the future of the brewery on, so we re-branded." It is now St Austell's most popular and iconic brew - rows on rows of brewing vessels in the warren of the 157-year-old brewery are devoted to Tribute, of which Roger is immensely proud.

But how did we get to the brewery? To summarise, the hop run went: 5.30am taxi, get train from London, meet Roger at Taunton, from where he drives us to a hop merchant. On the way he gives me the lowdown on British beer/hop history. This went something like: brewing comes to the UK with the Saxons; beers are spiced and have dual use as herbal remedies; hops introduced in the 14th century; during Henry VIII's reign hops were banned; in the 19th century hops became universal in brewing; in the early 19th century the malt tax was introduced; 1880 saw the Free Mash Tun Act; 1993 saw beer taxed by alcohol volume.

So by the time we reach the Charles Faram hop merchant ware-house near Malvern I'm a little better informed. Managing director Paul Corbett explains that there are only four hop merchants in the UK and that acreage devoted to hops has dwindled in this country as brewers turn to varieties grown overseas that have higher alpha acid levels (so they can use less). He does say this is now beginning to change as breweries internationally, particularly those in the US, look to experiment with British hops. US brewers have been experimenting and creating their own versions of India pale ales, for example, which were traditionally more 'hoppy' as this helped to preserve the beer while it was shipped long distances. "I've been out there and tried some US IPAs and decided to brew a 'proper job' IPA," says Roger.

"We didn't have a name for it and so I put that down on the beer sheet and it stuck. It's also a very Cornish expression." Roger's tutorial on hop biology goes something like: the flavour and character of hops are determined by the variety and also the climate and soil conditions. The hops' growth is triggered by increasing day length, so they can only be grown in two narrow bands of land around the globe. These include areas like Herefordshire, Worcestershire and Kent in the UK; parts of Belgium; the Czech Republic; the Ukraine; Washington State in the US; Tasmania, and New Zealand's South Island. "So it's no wonder that these are the places that have the strongest tradition of brewing beer," says Roger.

We then drive to the Capper family's hop farm near Suckley village on the border of Herefordshire and Worcesters-hire. Ali Capper walks us through the neat rows of the apple orchards - some of which are supplying Magners cider company. Paul is keen to take a look at a new hop variety that the Cappers are growing called endeavour, a US-style hop. However, we are here to pick the phoenix variety (although most of this has been done earlier) which will be used to create the Trelawney's Harvest Ale.

There's a lot of picking of hops, ripping them in half and sniffing them going on, and the consensus is that phoenix smells lemony and minty - which should come through in the beer. Then it's a quick lunch and we're back in the van, driving down to the brewery in Cornwall in a race against time to add the highly perishable hops to the brew.

Roger telephones James beforehand so he can get the brew started. Fortunately Roger doesn't fall asleep at the wheel (hops are supposed to have soporific qualities) and all goes well. But why go to all the trouble of driving 300 miles to brew a beer in a day? "It's a celebration of the annual harvest," says Roger.

He argues that it helps to show consumers the purity and goodness of beer - that only four ingredients go into it - malted barley (in this case Cornish maris otter barley), hops, water and yeast.

He adds: "People are interested in cask ale - in wholesomeness, products that are pure, having provenance, products that are craft-made, rather than produced in a large factory. They are interested in flavour."

Once the brew has been safely pumped into the brewing vessel (and everyone has commented on how frothy it is and how this is "probably to do with the hops"). I think of flavour as I bring the mud-coloured glass of liquid to my lips.

It's not quite beer as we know it yet, but give it a week or so and it should be really good.