We sat in the Wind Dog Cafe (01957 744321, winddogcafe.co.uk) at Gutcher on the island of Yell, waiting for the ferry to take us to Unst. Outside, the channel between the islands was grey, choppy and beaten by rain. Inside the Wind Dog Cafe it was bright and warm. The cafe might not subscribe to the niceties of modern metropolitan design chic. It is too practical for that. But then, most modern metropolitan cafes don't double as library, arts and community centre, and internet hub as well. Oh, and it's a great place from which to spot otters. The soups are rollicking, warming, homemade concoctions. There's a crofter's lunch of ham, cheese, oatcakes and pickle; bannocks are filled with cold Shetland lamb; the baked potatoes are island grown; and cakes, biscuits and pies are baked on the premises. Just the kind of food needed to keep the weather at bay.
"We have a phrase in Shetland. We say we're atween weathers," said Alastair Hamilton, my guide, mentor and passionate advocate of Shetland's foods, as we peered out the windows. It had snowed two days earlier, rarer than you might think in Shetland. The day before had been bright and sunny. Now rain was flying in on the wind.
Any visitor to Shetland - Shetland, mind, never the Shetlands; Shetlanders will purse their lips together in mild remonstrance should you say "the Shetlands" - had better go prepared for rapid changes in meteorological conditions. There are 100 or so islands that make up the archipelago. They lie, green and low, hummocks in the turbulent sea 130 miles to the north of Scotland. Like pieces of a jigsaw slightly strewn out on the sea, they look as if, with a little ingenuity, they could all be fitted back together. In a sense, they do all fit together. There is a strong sense of community and interrelation between the 15 that are regularly inhabited.
Not only is Scotland quite a long way away, geographically speaking, it's almost treated as a foreign country by Shetlanders themselves. You don't often see the Saltire on display. Tartans are nowhere to be seen. Indeed, it only became part of Scotland in 1469.
Alastair and I were on our way to the Skibhoul Stores & Bakery (01957 711304) on Unst, overlooking Baltasound, where Penny Thompson sells just about everything you might need by way of food supplies, but also makes Oceanic Oatcakes, so called because she has replaced the salt with seawater. In every other sense, they are classic oatcakes: mild, wholesome and addictive. I bought several packets to keep me company.
Inevitably, the sea dominates Shetland's history. During the late-19th and early-20th centuries, crafts, ships and fortunes were built on cod, ling and, above all, herring, caught on longlines from sixareens - six-oared fishing boats. You can see two splendid sixareens in the Shetland Museum (shetland-museum.org.uk) in Lerwick. Conveniently, the museum has a stylish canteen, where you can order traditional dishes such as a homely sassermaet (sausagemeat) burger, based on a 19th-century recipe, local salt beef, Shetland lamb bannocks and potted rabbit, as well as more modern combinations.
There's still a healthy fishing industry around Shetland, landing cod, herring, skate, saithe and halibut, but the innumerable inlets, crystalline waters and ferocious tidal races have made it a key centre in the mussel and salmon farming industries. It's impossible to miss the strings of large black buoys, like humps of the Loch Ness monster's back, neatly lined up in blocks, or the circular salmon pens.
Mussels and salmon cropped up on a good many menus. I had memorable mussels in a white wine and cream sauce at Monty's Bistro (01595 696555), a bright, lively upstairs restaurant in Lerwick (with a notably easily priced wine list, incidentally). The flesh of the crustacea was plump, sweet and quivery against the gently rich sauce. Thick slices of delicate, firm, close-textured smoked salmon contributed to a fine seafood platter at the Olive Tree (01595 697222), an immensely cheery deli-cum cafe in Lerwick, run by the redoubtable Bo Simmons. And just around the corner from the Olive Tree is the Hand-Made Fish Company (01950 422214, handmadefish.com) where Dave Parham, a refugee from Devon, produces superb smoked haddock and, to my mind, even better smoked organic salmon, experimenting with the effects of various woods, including larch (interesting and rather good) and juniper (too fugitive for my crude taste buds), while relying on old oak whisky barrels (smoky, sweet and brilliant) for his general stock.
Dave's smoked haddock surfaced on the breakfast menu at the comfortable and cosy Busta Hotel (01806 522506, bustahouse.com, doubles from £105 B&B), a 16th-century laird's house overlooking Brae Voe, where I stayed. Aside from big-hearted breakfasts, the kitchen makes full use of local lamb, free-range pork from Unst, Muckle Roe mussels, halibut from Bressay, and Yell Sound scallops. Even the milk, cream and butter are produced locally.
Indeed, generally, the raw materials in Shetland are as good as anywhere in the UK, which means they are very good indeed. I couldn't say that public cooking yet is in quite the same class. However, the Shetland Islands Council is beginning to address the need, and this month saw the first Shetland Food Festival, opened by Jean-Christophe Novelli, who immediately sent the local rumour-mill into overdrive by declaring that he wanted to open a cookery school on one of the islands.
There is a good deal to be said for meandering up through the islands, as I did. For the outdoor enthusiast there are great walks, such as along the black basalt cliffs at Eshaness. There's fishing to be had in the sea and lochs. There's a good deal for the keen birder. And there's plenty of evidence of Shetland's vigorous past going back 3,000 years, particularly the monumental brochs, giant stone towers like hives.
As my flight lifted into the air from Sumburgh airport, I looked out of the window. The land and sea below me were bathed in warm sunshine. Was that just a lull atween storms? Or had the new weather arrived?
• NorthLink Ferries (0845 600 0449, northlinkferries.co.uk) sails Aberdeen-Lerwick, from £21.40pp each way. Flybe (0871 700 2000, flybe.com) flies to Sumburgh, Shetland, from 13 UK airports. Visit Shetland (0870 199 9440, visitshetland.com). Shetlandfoodfestival.co.uk.