Sometimes you need to keep a lobster alive for a recipe but you may need to purchase it ahead of time. Thus, you have to keep it alive overnight without a salt water tank and while you may be tempted to just put it in the bathtub or sink, that will actually likely kill it. It is simple to keep a lobster alive overnight. You just have to allow it to go into a sort of coma and then it will stay alive.
Things You'll Need
Purchase a live lobster from your local supermarket or other market grocer. Take it home immediately. Remove the wrapping or take it out of the box.
Clean out a drawer in your refrigerator, preferably the lowest drawer there is. Typically, it's the vegetable drawer.
Wet several paper towels. Wrap the towels around the lobster, claws closed. Make sure you completely cover all parts of the lobster.
Place the lobster in the empty drawer. Close the drawer and keep it shut. Leave it in there overnight, undisturbed.
Remove it from the drawer when you are ready for cooking. Unwrap the towels and throw them away, then cut off the rubber bands around the claws. You are ready to make your favorite lobster dish with fresh lobster.
Wait until the last minute to buy the lobsters so they'll be more likely to stay alive.
Don't store the lobsters in water, it will kill them.