I was kinda curious how the secret service might go about keeping the president’s food supply secure (or how the food of any important head of state is protected). Is it a safe bet that agents must be present in the kitchen for the preparation of any meal the pres might eat? What about before the raw food gets to the whitehouse, how might the SS go about ensuring that no one has poisoned the president’s eggs, flour etc?
The Secret Service does the White House grocery shopping. The chefs, naturally, have extensive background checks and whatnot. I don’t know if there are any extra food security protocols at the White House specifically, though. The Secret Service has admitted to using mice and other mammals as food testers when the President was visiting a foreign country.
My wife has personally sold and shipped cheese to White House parties on several occasions. The White House kitchen calls, asks a few questions and requests that everything is shipped as it was packaged when it came in from Europe. Other than that, I don’t think they do much more at least for those.
When shopping for groceries the Secret Service goes to different suppliers infrequently. This is so that no person could predict anything concerning the shopping of the President’s food supplies. One can see the precautions taken when one reads of Roland Mesnier, the jolly old French Executive Pastry Chef, once having to make 1,500 cookies without any assistance: