2 to 3 days. Oyster cakes can last for 2 to 3 days. The oyster cake can be vacuum packed and stored for 2 to 3 days after it is made. Sea oyster cake is a fried snack with rice flour (pulp) and soybean flour (pulp) as raw materials. The taste is crisp and delicious, it looks like a circle, its color is golden, and its shell is crisp and fresh, so it can be eaten as a snack alone.