Former research scientist turned ''aquaculturist'' Clive Keenan is the only commercial producer of umi budo in Australia and he is not keen to have competition. Asked how he grows the edible seaweed, Keenan laughs. ''That's a secret,'' he says. ''We tried a lot of different methods until we came across the perfect conditions.''
Keenan produces the seaweed, also known as ''sea grapes'' or ''green caviar'', on his aquaculture farm, Coral Coast Mariculture, west of Bundaberg in Queensland. The product been attracting attention since it was released on the market in April and presented to a who's who of chefs and the public at the Noosa Food and Wine Festival this month.
The seaweed, Caulerpa lentillifera, which forms in tiny salty spheres, was originally farmed in Okinawa, Japan. There, it is known as ''the longevity seaweed'' because of its high mineral and low calorific content. In Japan, and in the Philippines, where it is also grown, the seaweed is served with vinegar, as part of a salad, or offered as a bar snack.
Despite preferring warmer temperatures, umi budo has found its way onto menus at Huxtable, Akachochin and Virginia Plain.
''At the moment, I'm using it on kingfish sashimi with Campari salt,'' Andy Harmer, head chef at Virginia Plain, says.
''A lot of my customers haven't seen it before, so they're surprised by the burst of flavour, but the feedback has all been positive.''
James Campbell, head chef at MoVida Sydney, says he was introduced to seaweed recently by chef Frank Camorra and is using up to two kilograms a week.
''It doesn't sound like much, but you need only a small amount,'' he says. ''I'm using it on an oyster with finger lime, which not only gives that visual interest, because of the contrast of the grapefruit-pink fingerlime and the vibrant green of the umi budo, but also a burst of seawater against the citrus which is amazing.
''I'm thinking about ways to use it with caviar on a dish, too. Unlike fish roe, which is soft sphere, it's quite firm, then just pops in your mouth and I think that textural contrast would be quite special.''
Michael Canals, director of food wholesaler CQ Foods, says there has also been ''enormous interest'' from fruit and veg suppliers.
Seaweed needs clean water and a mild tropical climate to grow. Keenan says his farm's position, on a pristine saltwater creek flowing out to Hervey Bay, is ideal.
''Under perfect conditions, we are capable of producing 275 tonnes a year.'' he says. ''We've already had inquiries about exporting it.''