Rain on the windowpanes and back-to-school mornings. Nights drawing in and a chill in the air that makes us crave open fires and rib-sticking feeds. Even when buoyed by an Indian summer, September is the month that sees summer's spell broken. But those September clouds do have a silver lining - or rather a mother-of-pearl, creamy pink, mushroom-grey lining, as any pedantic ostreaphile might tell you.
As the first month with an 'r' in it since April turned to May, September heralds the traditional opening of oyster season across the Northern Hemisphere. And right around our little island, annual oyster festivals are gearing up to welcome fans of these gastronomic pearls - and throw a famously good party while they're at it. One kicks off today in Cork's Metropole Hotel, another next weekend at the 64th annual celebration of the Galway International Oyster & Seafood Festival.
Even better news is that appetites for Irish oysters can now be indulged year-round and countrywide. Hip oyster bars have joined the traditional pubs and market stalls as purveyors of these briny beauties, while a new seafood trail is uncovering the local stories behind this world-class luxury food.
Like many folk wisdoms, the simple 'r in the month' rule gets a little muddier on closer inspection. Historically, your chance of getting a 'bad' oyster was significantly lessened during colder months when water temperatures keep algal blooms under check. Thanks to today's close monitoring of naturally occurring toxins, however, combined with highly efficient purifying systems and fast, refrigerated distribution, the greatest risk involved in consuming commercially harvested oysters is probably a question of self-control.
Once you acquire a taste for these most natural of sea foods, characterised by one French poet as "like kissing the sea on the lips", the challenge might be in knowing how much of this richly delicious and highly nutritious food is too much of a good thing - not to mention the pints of stout or crisp white wines that wash them down so well.
Another reason for the r-month rule is that, much like ourselves, oysters respond to winter temperatures by carrying a little extra weight, making for meatier eating from September onwards. During the warmer months oysters focus their energy on spawning, causing the flesh to become thinner and milkier.
Of the 10,000 tonnes of oysters harvested annually in Ireland, however, 95pc are the Pacific rock oyster (crassostrea gigas) introduced to our shores in the late 1970s in face of severe depletion of our native flat oyster (ostrea edulis). Rock oyster don't reproduce in our cold coastal waters, but begin life in hatchery as teensy spats the size of a match head. Most are bred to sidestep that awkward summer spawning period, meaning that plump Irish rock oysters are available year-round.
Some 500 tonnes of native oysters are still harvested here in Ireland every year, and it is these that are celebrated in Galway next weekend. "The native has a stronger umami flavour and then that signature dry metallic finish," says Diarmuid Kelly of the Kelly Oysters of Kilcolgan, who export these unique rarities worldwide. "The rock oyster has a lighter taste; you still get that distinctive sea water flavour but not the same depth of finish."
Learning from history, our fishing authorities manage wild stocks of native oysters to ensure their sustainability. Now that the summer spawning season is over, native oysters are back on the menu as a local luxury, served up at the Galway festival marquee and street stalls as well as local restaurants like Loam (where chef Enda McEvoy describes them as "unique, sweet, gamey, floral and briny") and even chippers like McDonaghs, where you can add them into your order of fish'n'chips.
The Kelly family have supplied the Galway festival with native oysters since year two, in 1955. They remain at the heart of the action, which will see oyster aficionados descend on Nimmos Pier to show off their 'shucking' skills at next Saturday's World Oyster Opening Championships. The festival now includes everything from Saturday's Masquerade Mardi Gras banquet parade to Sunday's free family-friendly cooking demos, Féile Bia Na Mara.
If you had the constitution, you could spend the next three weekends at a different oyster festival - and the weekdays at two month-long oyster festivals, one in Dublin's Shelbourne Hotel and the other running simultaneously at Ardmore's Cliffhouse Hotel, Dublin's Cliff Townhouse and The Cliff at Lyons with live music, festival menus and much more besides.
The Clarenbridge Oyster Festival (October 4-7) is a community-run off-shoot of the Galway festival, and features a family day on Sunday 7 with an artisan food village and children's food workshops.
Meanwhile this weekend's Murphy's Cork Oyster & Seafood Festival welcomes Paddy 'the Shucker' McMurray, world record holder for despatching a whopping 39 oysters a minute. Paddy hosts free cookery demos this afternoon, before joining MC Derry Clarke of l'Ecrivain for tomorrow's All-Ireland Oyster Shucking Competition. Joe Harty of Harty Oysters in Dungarvan Bay will provide the locally cultivated oysters - and a bit of drama with his Murphy's-based recreation of the impromptu 'Shuck, Suck and Sup' party that he hosted on the Great Wall of China as part of last year's Shuck Off World Cup in China.
"We paired Harty oysters with Blackwater Gin for a real taste of Waterford," he tells me, "using the empty shells as our shot glasses!" If it's a brave man who tried the first oyster, it's a braver one still who suggests an oyster and gin pairing - although as a fella who claims to down 60 oysters during an average working day, Joe seems well able for any such challenge.
Harty Oysters are typical of a new breed of Irish oyster producer who are playing clever with their premium product. Most are still exported, as they have been since the 19th century when they were shipped to London's top restaurants in such numbers that stocks became dangerously overfished. Once the rock oyster arrived in the late 1970s, that export market was embraced by the French, who consume a massive 90,000 tonnes of oysters every year, as well as distributing oysters - including Irish-grown ones - to a fast-growing Asian market.
The Harty family decided to skip the middle man and to brand and sell their Speciale Oysters directly. As with so many of our oyster producers, 95pc of their harvest is still exported.
But the good news is that these Dungarvan Bay oysters with their clean estuary-influenced cucumber notes are becoming more widely available to us Irish too: at the Douglas Farmers' Market during summer months and on oyster bar menus at the likes of Klaw, Sole and the Cliff Townhouse in Dublin, all of which offer a chance to compare different oysters from around Ireland.
"Oysters from different bays have very distinctive flavours," explains Richard Donnelly of Bord Iascaigh Mhara (BIM), where he has developed the new Taste the Atlantic seafood trail in collaboration with Fáilte Ireland's Wild Atlantic Way. "I would be fairly confident to tell you which oysters come from each place just by taste," Richard says, a claim that seems less far-fetched when you consider that oysters, like wine, take their character from the environment in which they are produced.
"With oysters, all the feed comes from the natural environment, and each bay is different depending on water type and levels of minerals and microscopic organisms. If there's a lot of feed available, the oyster becomes fatter with a richer flavour; if you've a lot of fresh water from river, it's not as salty." Likewise, estuary-grown oysters might show vegetal flavours of samphire or cucumber, or sweet peaty notes from boglands of Connemara or Donegal.
The Taste the Atlantic trail taps into our renewed interest in the story behind our indigenous foods. "When you dig down, we have a really rich heritage," Richard says, pointing to a history of oyster cultivation dating from the 16th century, and evidence of oyster consumption for over 5,000 years. "We wanted to tell that story through the story of the people and families producing our seafood today."
Of the 21 seafood producers whose new visitor experiences are highlighted on the interactive trail map, a third specialise in oysters - stretching from the Inishowen peninsula in Donegal down to from Killorglin in Kerry. A visit to them highlights the dedication that goes into growing an oyster from tiny seed to quivering beauty on your plate - a process that takes at least three years in our cold water climate and involves hard physical labour to keep the oyster shells and inner meat in perfect shape.
Like the micro-climates that they operate within, each visitor experience is unique; put together, these stories reveal a complex food heritage.
Connemara's Ballinakill Bay is home to one of Ireland's oldest oyster farms. Now run by David Keane as DK Oysters, it was established in 1893 as one of several oyster farms belonging to the landed gentry and supplying an oyster-mad market in London. Records from the 1800s reveal a rapid development of that export market: accounts of oyster fishing further north in Lough Foyle show a five-fold increase from eight boats in one 1830s account to more than 40 by the 1860s.
"People often question why, during the Famine, we didn't just go down to the shore and pick oysters to feed ourselves," Richard says, "but you have to remember that we're talking about an extremely valuable resource. Even then it was a luxurious food and these were protected areas - and anyone found picking them without a licence would be on the next boat to Australia."
The most northerly Taste the Atlantic trail experience tells the story of Crocknagee Oysters at the surprising location of the Dough Famine Village. "Derek Diver of Crocknagee Oysters is now employing 20 to 30 local people in the same place as one of those 1850s farms - but the difference today is that these farmers are not landed gentry anymore."
Today these are small-scale local operations, some handed down through generations as with the Kelly and Harty families, and the Gallagher family of Irish Premium Oysters in Donegal's crystal-clear Tragheanna Bay. Edward Gallagher looks after the largely export business ("We started exporting to Hong Kong and Taiwan in early 2000," he says, "and from there have moved to Malaysia, Japan, Dubai, Singapore, Thailand and China") leaving his semi-retired father Jimmy to welcome visitors onto their turf and share the secrets of their trade.
"He brings people down to the shore and talks through from when we receive the seed right through to the fully grown oyster, and explains about our two sites, including the final fattening site where the water is quite brackish and gives them a unique taste," Edward explains, "and he takes them up to our fancy oyster cart and shows them how to open an oyster the proper way."
Others operations are working together in emerging producer networks, as with the four family-run businesses trading as Wild Atlantic Oysters, which includes three Sligo-based oyster farms supplied by one local hatchery at Lissadell House, which itself has an oyster heritage dating back to the 1860s.
Visiting some oyster farms can be a mucky experience, especially in shallow estuaries, so one local entrepreneur has stepped in to showcase the Sligo Oyster Experience. Aisling Kelly runs WB's Coffee House in her family's former pub, where three days a week (Thursday to Saturday) her cafe turns oyster bar. Visitors can drop in for Wild Atlantic Oysters served in various guises, including her excellent four-cheese oysters, or book onto her afternoon tour to get a fuller insight into the rich history of oysters in Sligo (or Sligeach, meaning 'Shelly River') with its sandstone-based Garravogue estuary that flows seven kilometres to Oyster Island and the midden-covered coasts at Strandhill and Rosses Point.
Inspired by the positive public reaction to the Taste the Atlantic trail, other oyster farmers like Joe Harty are now looking to open up their busy working farms to curious visitors: Joe plans to have bookable tours on offer before next summer.
For Joe, as for Richard Donnelly at BIM, these tours offer an ideal opportunity to showcase the pristine and unique working environments of Irish oyster farms to international visitors.
For us Irish oyster lovers, they are an open invitation to discover some of the most fascinating food stories right on our doorsteps.
They say it was a brave man who ate the first oyster, and eating your first oyster can take a little courage - but you'll be rewarded with one of the best eating experiences that nature can offer. Here's a few tips to ready yourself:
● Eating fresh oysters raw is the best way to experience their nuanced flavour and meaty texture, but first-timers might prefer to try them cooked - perhaps Kilpatrick style with bacon and Worcestershire sauce.
● If eating oysters raw, try 'au natural' with just a squeeze of lemon added to the natural salt water within the shell, or add a drop of Tabasco for a little heat.
● When eating directly from its shell, ensure the oyster has been cut loose at the connecting abductor mussel before bringing up to your mouth and tipping it back.
● To chew or not to chew is up to you, but certainly a few gentle chews will help to release those gorgeous flavours of the sea and may feel less intimidating than swallowing an oyster whole.
● If serving oysters at home, look online for a video tutorial to help you shuck them correctly and try microwaving for a few seconds to open slightly and give you better access with a strong blunt knife.
● Oysters are an equally great match with the bitter-sweet flavours of stout; the crisp acidity of white wine (think a mineral-laced Chablis, Sancerre or Muscadet, or a marine-influenced Albariño) and the bone-dry salinity of a Manzanilla sherry - though general advice is to avoid them with spirits.