Oysters with Lemon Caviar and Seaweed Puffs

pescatarian, gluten free // makes 12 oysters

Moonstone oysters, spherified lemon juice, seaweed rice puffs, and wasabi microgreens. This is the third dish in my 2021 Series of Five Sustainable Dishes, a project supported by the Stanford Office of the Vice President for the Arts. The series is a personal exploration of the various meanings of “sustainable food”. My goal with this series is to consider some angles from which food and food products can be considered good for the environment.

Here, moonstone oysters, a medium-to-strong brine oyster with a sweet finish, are the main event. Meyer lemon juice is spherified into lemon caviar. The caviar is then dotted across the open oysters for a literal “pop” of acidity. Rice is blended with seaweed, dehydrated in sheets, fried into puffy crackers, and tossed lightly with sea salt. Mustardy micro wasabi pair well with the oysters.

Oysters, mussels, scallops, etc. are bivalves, a group of shelled, filter-feeding marine animals. The environmental impact of the farming, or aquaculture, of these animals is characterized as benign to actively restorative. While meat and fish have a greater environmental footprint than plant-based foods, the footprint of bivalve aquaculture is even lower than many arable crops in terms of greenhouse gas emissions, land and freshwater use. Bivalves can be considered one of the most sustainable foods you can eat, for a number of reasons:

1. They require no feeding and minimal to no antibiotics/agrochemicals.

2. They sequester carbon in their shells. This permanently removes carbon from the oceans and atmosphere (at least, on the time scale we’re concerned about), an aspect that will become more important as the warming of the oceans diminishes the ocean’s carbon absorbing capacity.

3. They protect fragile ecosystems by eating algae and organic particulates in the water, reducing risk for eutrophication (excess nutrients in water resulting in harmful conditions of anoxia), and have even been used in the United Kingdom to clear docks of harmful eutrophia and overgrowths of detrimental algae without any other environmentally disruptive interventions. Bivalves can also excrete marine pollutants back into the land system as sediment, which locks those pollutants away for a long time.

4. Bivalves are the basis for biodiverse marine ecosystems. The reefs they help form create habitat for wildlife, such as nursery grounds for fish.

Meaning: the more bivalves you eat, the better for the environment (a simplification, but a decent one nonetheless).

Eating more seafood is one way the world food system can supply high-quality protein to a growing population with evolving nutritional demands. Seafood has remarkable potential to fulfill the dietary needs of vulnerable populations, and is a viable alternative to intensively-farmed meats like beef. Done right, aquaculture can be incredibly sustainable, and may play a vital role in feeding more people and feeding people better food while also incurring fewer emissions, less land use alteration, less fresh water usage, less antibiotic usage, and better feed conversion.

I suggest looking toward resources like the Marine Stewardship Council, Monterey Bay Aquarium Seafood Watch Program, etc. to learn more about sustainable seafood.

Product spotlight:

• Nassau Street Seafood: Moonstone Oysters

• Modernist Pantry: Spherification Kit. Includes calcium chloride, sodium alginate, and sodium citrate.

• Gourmet Sweet Botanicals: mustard flowers, micro wasabi, petite sea fennel, ice buds

what you need:

for the oysters:

• 12 live raw oysters. buy them closed (unshucked).

Tip: sometimes i go for just 6 oysters but still make the full amount of seaweed rice puffs and lemon caviar. the puffs are great for snacking, and lemon caviar can be used to add excitement to many other dishes!

for the seaweed rice puffs:

• 2 cups overcooked white rice (boiled until very soft and mushy). you can repurpose leftover white rice for this, just add into back into a pot with some water and continue cooking until it breaks down further.

• 12 pieces of snacking seaweed, each about the size of your palm

• 2 tbsp water

• sea salt, to taste

for the lemon caviar:

• 500 g meyer lemon juice

• 8 g sodium citrate, adjust as needed

• 5 g sodium alginate

• 1 L water

• 5 g calcium chloride

optional, to decorate:

• edible flowers: mustard flowers

• microgreens: micro wasabi, petite sea fennel, ice buds

how to make it:

to make the seaweed rice puffs:

1. preheat oven to 170 F. line two baking trays with silpat.

2. in a high speed blender, blend all ingredients until a smooth mixture is achieved.

3. using an offset spatula, spread the mixture across the silpat as thinly and evenly as possible.

4. dehydrate in the oven for at least 3 hours. check back once in a while to ensure the mixture is drying out. after the sheets solidify, use scissors to cut them into 4 pieces and continue dehydrating. this will encourage the sheets to dry out fully and evenly. after they are dried out, break or shatter the sheets into random shapes. these shards will expand at least 3x their size once they are fried.

5. get ready to deep fry. preheat enough oil on the stovetop to 400 F. prepare a cooling rack for the puffs once they come out of the oil.

6. drop a handful of seaweed rice shards into the hot oil. they should immediately puff up. once they have puffed (should only take a few seconds), use a spider to remove them from the oil and drain them on the cooling rack. while the puffs are still hot, sprinkle lightly with sea salt to taste.

to make the lemon caviar:

follow Modernist Pantry Spherification Kit package instructions.

1. create the sphere base. in a glass container, combine lemon juice and sodium citrate. place into the fridge to chill for 30 minutes. after 30 minutes, take the lemon juice out from the fridge. using either a whisk or an immersion blender, begin mixing the liquid to create a vortex. sprinkle the sodium alginate on top of the liquid, continuing to mix until it is fully dispersed. try to minimize the amount of air you incorporate into the liquid while mixing. place the alginated juice back in the fridge to hydrate for at least 2 hours and preferably overnight to allow any bubbles in the mixture to dissipate.

2. create the setting bath. pour water into a glass container and whisk in calcium chloride until it is fully dissolved.

3. create the caviar: dip the tip of the syringe in the sphere base and fill it by drawing back the plunger. hold the syringe 3-4 inches above the setting bath and press the plunger to dispense the liquid into the bath one drop at a time. let the droplets soak in the setting bath for 1-3 minutes in order to form a skin. the longer they remain in the bath the thicker the skin will be. remove the newly formed beads from the setting bath with a small strainer. rinse the caviar with water in a clean bowl at least twice to remove any residual calcium chloride (which has a bitter taste) and to slow the setting process.

TIP: this step cannot be done too far in advance, as the lemon caviar will continue to gel inward, turning the liquid center solid. if you are interested in keeping the center liquid indefinitely, try reverse instead of direct spherification.

to serve:

shuck oysters. place on a serving platter. dot each oysters with a few lemon caviar, and serve the rest on the side. arrange seaweed puffs and, if desired, microgreens and edible flowers on the platter. enjoy.