How We Farm: Tumbled Oysters

Tumbling farming is such a new technique that oyster farmers haven't even settled on what jargon to use... some farms call their tumble bags "tumble bags," others call their tumble bags "tipping bags." (And if that didn't strike you as a totally biased turn of phrase, then we've already got you hook, line, and sinker!) There seems to be consensus that British Columbia farmers were the first to tumble oysters. In BC and other points north, they don't farm on tideflats, but instead grow their oysters suspended in racks, subtidally. Subtidal oysters are always underwater and basically have 24/7 food, so they grow fast. Here's a photo of our friend Weatherly Bates from Glacier Point Shellfish, who farms subtidally up in Kachemak Bay, Alaska (read more about her farm here):

But when an oyster feeds constantly and grows quickly, its shell can become brittle. If you've ever shucked an oyster only to have it fall apart in your hands, you understand how disappointing a brittle shell can be. Building on centuries of oyster farming techniques perfected in France (the French "rack and bag" system), BC farmers figured that by agitating their oysters they could strengthen the shells. So every once in a while, subtidal farmers have to haul everything up and run their oysters through a tumbling machine:  

As an added benefit, tumbling oysters drastically improves their shape, giving them nice deep cups. The BC tumbled oysters were so nice that it didn't take long before farmers from other locales began experimenting with the technique. Farmers in Australia are credited with first using tidal energy rather than diesel to do the tumbling. In South Puget Sound, Chelsea Sea Farms first rigged up a tide tumble system. (Their tumbled oyster is called a Chelsea Gem, and it's delicious). So tumbling helps with two problems: it strengthens the shells of oysters that are growing quickly, and it prunes oysters into a more desirable shape. We sometimes refer to tumbled oysters as oyster topiary. Think box hedges and Edward Scissorhands. Just how bad can an oyster's shape get? If a wild oyster sets between a rock and a hard place, it can grow up all twisted:

Or, if an oyster is growing too quickly or in crowded conditions, it can get long and skinny. We have quite a few of these so-called "bananas" on our beach, remnants from the days when tremendous natural sets loaded Hood Canal beaches with wild oysters. If you're foolhardy enough to attempt to slurp down an oyster this size, be prepared for it to slap back:

During tumbling, an oyster's delicate new growth gets broken off, causing it to put energy into forming a deep cup instead of growing longer. Oyster shell new growth comes in all sorts of colors: blue, pink, purple, dark grey, or white, as you can see in the photo below:

To tumble oysters on an intertidal farm, you put some posts out on the beach, string a line between the posts, attach bags full of oysters to the line, attach buoys, and then let the tide do the rest of the work. When the tide comes in, the buoys float and the bags flip up. When the tide goes out, everything falls down 180 degrees. This is the way our tumble farm is set up, and it's definitely a work in progress. We're still tweaking with the construction: experimenting with new ropes, clips, buoys, and bag orientations. There are all sorts of variables: too much floatation, and you worry that the whole darn thing will rise up and float off. Not enough floatation, and you might not get the tumbling action necessary to prune the oysters. Too deep, and there won't be enough of a tidal change to tumble the oysters... too shallow, and the oysters will spend too much time out of water and will grow slowly. Too many oysters in a bag, and they won't tumble well. Too few oysters in a bag, and you're wasting your time. And if you get a mussel set in your tumble bags, forget about it. The mussel byssal threads tie the oysters up into knots, preventing anything from rolling around. Our tumble farm in 2010, when it was brand spanking new:

(We really love this photo because you can see that the bags in the background are already starting to float with the incoming tide.)

Our tumble farm earlier this winter, after a few seasons of being beaten to a pulp by the south wind:

Tumbled oysters aren't just cosmetically different from other oysters. The shape of the food we eat affects the experience of eating it: Think about how shredding carrots versus cubing them can change the flavor of a salad, or about how drinking a Sauvignon Blanc out of a paper cup can change how you feel about the wine. Compared to beach grown oysters, tumbled oysters normally have a more compact body and retain their liquor longer after being shucked. They're also easier to shuck. And because they have a different diet (more food, different kinds of food) than beach grown oysters, they have different flavors and seasonality. So when we started producing tumbled oysters, we had to come up with a new name for them: in appearance, texture, and shape they were a very different product from our beach grown Hama Hamas. We settled on "Blue Pools," a name inspired by one of our family's favorite swimming holes. For us, tumble farming has been an eye-opening exploration of our beach's merroir, allowing us to farm in previously inaccessible eddies and currents. Here's a parting glamor shot of one of our Blue Pool Oysters: