Vidalias & Walla Wallas are sweet varieties of yellow globe onions.

Onions are an important part of cooking.  Vidalia and Walla Walla are varieties of what kind of onion?

Feta is a sheep's-milk cheese made in Greece since the 8th Century BCE.

Most regions of the world have some form of local cheese.  What nation is considered the home of feta cheese?

Reggiano (the "King of cheeses") is a parmesan that must be made via highly specific ways in specific locations to qualify as Reggiano.

San Marzanos are the gold standard of cooking tomatoes, canned and shipped to kitchens worldwide.

Wilbur Scoville, an American pharmacist, developed this scale which rates how dilute a pepper can be while still having detectable piquancy.

Spices can be seeds, bark, roots, rhizomes, but they can't be leaves.

Cilantro is the greenery and coriander is the dried seed from the same plant.

Rhubarb leaves contain oxalic acid and anthone glycosides that should not be consumed by humans.

Only rhubarb grown in the tropics is edible

Yes, the notorious poison belladonna (deadly nightshade) is related to the potato as well as several other popular vegetables.

They are also related to each other, members of the Zingiberaceae family.

Cranberries grow in very wet conditions (bogs in the US and fens in the UK). 

Fermentation is absolutely essential to wine and risen breads (no, soda breads don't qualify), yeast being the essential ingredient to both.

Yes, the "corned" term refers to the rock salt used in early preparation, though modern versions often use finer forms such as kosher.

Kosher salt is actually "koshering" salt... salt which helps draw blood from meat which would make it "trefah" (forbidden).

Iodine is needed for proper thyroid function, preventing goitres, etc.  Two billion people worldwide may suffer from iodine deficiency. 

Sugar originated in India with granulated sugar being first recorded over 2000 years ago.

Apples come in over 7500 (yes, seven THOUSAND five hundred) varieties.

Yes, while spices and flavorings can vary from recipe to recipe, pastrami is defined as being smoked while corned beef is not.

Charcuterie literally means "cooked flesh".  Yeah, it may be truth in advertising, but "charcuterie" sure sounds more appealing.

While pasta can be made from any of the above, duram wheat is the historical basis of Italian pastas, both fresh and dried.

Good food is one of the great joys in life, but how much do you know about the ingredients going into that food?