Oysters: the latest addition to Shetland’s superb seafood menu

Over the years, Winston tried eating oysters in many places. In Europe and the UK, the oysters that are usually farmed are the Pacific type. However, he was also interested in growing the European native oyster, also native to Shetland.

“The holy grail was to get the native oyster to release spat in its natural surroundings; so, when I got back, I looked into it a bit more and applied for a works licence. Once I received that, about 16 years ago, there were issues with getting spat of good quality, so we paused our plans as we didn’t want to introduce potential diseases. And working life had its effect as well, but I thought now or never, so I started a trial in 2020 with around 15,000 oysters, while working from home during the pandemic.

“We have over half a million in the water now, a mixture of native and Pacific oysters. We have a small amount ready, but we sold some at Christmas and the other half we’ll look to go in early February, for Valentine’s Day.”

Once the water temperature increases in the spring, more of the oysters will reach maturity. “Hopefully, by the time the summer season and the Tall Ships arrive, they’ll be ready."

The oysters grow naturally in the sea, and Winston has arranged the growing area so that it’s in the intertidal zone. “That’s one of the issues in Shetland and why it’s more difficult to grow oysters here – we don’t have the rise and fall of tide that they have south. You could go in with a tractor south, but I was working with a small skiff; I proved that worked, although it’s more effort, so we built a pontoon. We just push that out and we gain access that way.”

The spats are “about fingernail size, 0.1 to 0.2 of a gram, and they go into small-mesh bags, placed on trestles. They start growing. You need to keep turning the bags. Everything’s fighting for the same food. You need to keep down on weed growth; in certain areas, below the burn, we get a lot of weed growth, and then about 50 yards away, you’ll get no weed growth, only barnacle growth. It’s the difference in salinity.”

In contrast to mussel farming, in which the mussels simply grow, unattended, on suspended ropes, the process of growing oysters is labour-intensive. There’s a lot of manual handling of the bags and the oysters, to control that weed growth and maintain the flow of water to the oysters. “We don’t have the tidal rise and fall, but we’ve got a really good water flow here, and plenty of food in the voe, so we get good growth in the summer.”

In fact, Winston says, it’s pretty much a matter of looking after the oysters individually. If they’re left unattended, “they’ll fight for the water, so they will start growing odd shapes – we call them rabbit-lugs. You’re looking for that tear-drop shape.”

The mesh bags in which the oysters grow rest on trestles. “We took the French design of trestles, and the first winter we had, although Weisdale Voe is relatively sheltered, they all toppled. We lost the whole lot.” So, the trestles had to be modified, and held down with anchor chain.

“It’s all a bit of trial and error. We’ve made a lot of mistakes but we’ve learned an awful lot and we learn all the time. We started off hand grading. If you get an oyster twice the size of another oyster, it’ll take all the food. The other one won’t grow, so we always try to maintain consistent sizes in each bag.”

As numbers increased, hand grading became unworkable, and some mechanical assistance was needed. However, the cost of a grading machine was “through the roof; we couldn’t afford that, so we developed a machine just by looking at YouTube videos. We managed to build a tumbler machine along with L&M Engineering and that helped us get going; it’s been a godsend. We’ve added a conveyor belt that helps with the manual handling as well; it’s just evolved.”

The first sales of oysters, just before Christmas, was on a small scale, but it was, Winston recalls, “very intense. We wanted to get them to the customers as fresh as possible, so we were packing at night and delivering in the morning and through the day.”

The feedback from customers was excellent. “It was 50% people who knew oysters and who wanted to try them from Shetland, and the other half was folk that’s maybe never tried them before and were wanting to see what they were like. We offered knives as well, because you can’t open an oyster, really, without one.”

Shetland is obviously quite a small marketplace, so exporting oysters is very much part of the plan. However, the first priority will be quality. “We’re never going to be very big, by the nature of the site, and we want to focus on the quality of the product.”

A great deal of thought and experimentation has gone into achieving that aim. Once the oysters are removed from their mesh bags in the sea, they are purified (depurated) to ensure that they are in the best possible condition and free from any contaminants. “The plant that we have, we depurate for 42 hours and then they can remain in that condition. It’s their own seawater – we bring seawater up from the voe and it goes through a UV filter. It doesn’t affect the taste or anything, but it’s a good insurance policy. They can stay in there up to a few days afterwards. If we didn’t have the depuration plant, we wouldn’t be able to sell them directly from the croft. With the plant, a customer in a Lerwick restaurant can eat an oyster a couple of hours after it has come out of the water.”

In fact, oysters that have been properly treated have a good shelf-life. “I’ve done trials here. They become dormant below 6 degrees, so they just close up and hibernate, basically. I’ve tried them up to two weeks and saw no difference. I’ve not gone beyond that. We put a packing date on each batch, and they can easily last a week after that.”

The oyster market is, to some extent, a special-occasion one, but the interest from restaurants is growing. Winston points out that where oyster-growing is traditional, so is eating them. He hopes that that will become the case in Shetland, and he would hope to keep the costs down so that buying oysters can be affordable.

For export, he plans to work with well-established distributors on the UK mainland, and with a local firm. Ordering through a website will probably be possible and there’s been “a lot of interest”. But “we want to maintain the focus on quality, not try to do too much, and just slowly build up the reputation. The oysters take quite a while to grow, so we’ve a bit of time to set our stall out.” Since Pacific oysters take 3 - 4 years to mature in Shetland’s relatively cold waters, and the native oysters up to 6 years, “it’ll be another couple of years before the natives are ready.”

Winston is confident that the quality is very good indeed. “I’m biased, but I’ve tasted them in a lot of places, and I think they’re up there. There’s a chap from New Zealand, a big oyster aficionado, who says it’s the best he’s ever tasted. I don’t know him at all, and I didn’t pay him for the quote! It’s really good to hear others saying it.” It’s been a long time since this writer sampled his last oysters, in Dieppe, but I can confirm that the quality of these Weisdale Voe oysters is outstanding, with superb flavour and texture.

This is down not only to Winston’s painstaking husbandry but also to the choice of site, which is crucial. Winston explains that several factors are involved, including the substrate, the clarity of the water and how fast it flows. Temperature and salinity are ‘critical’, he says. During depuration, the temperature mustn’t drop below 8 degrees, or the oyster won’t filter; and oysters won’t feed if the water becomes too brackish, so he has to monitor salinity as well. “Thankfully, we test the salinity and it’s sufficient.” In fact, some fresh water can be beneficial; “it adds to the taste, it’s a slightly creamier taste. It’s a bit like wine, with terroir. In France, they call it the merroir, the sea environment.”

In France, Winston adds, they offer oysters that have been grown in both brackish river water and in the sea, and it’s possible to go on a tasting tour to sample all that’s available. “The oysters very much take up the taste of their location. And we have a unique location.”

Ensuring that the oysters enjoy an excellent reputation, linked to Shetland, is vital for Winston. “I have to maintain the quality, given the provenance of Shetland produce and how people put a lot of effort into that. Having the depuration plant gives an element of independence; if we were just shipping away to a big distributor then the Shetland name would be lost. I think folk are paying more attention to where their food’s coming from.”

That commitment to quality and provenance will surely stand Winston in good stead. The project has involved substantial investment of money, research and experimentation. The reward has been a long time coming, but he now has a product that he and Shetland can be proud of. It’s great to see – and taste – the truly excellent results.