Sweetbreads may be the perfect introduction to organ meats. But what are they anyway?  And why the name?

The Thymus Gland

Sweetbreads are the culinary name given to the thymus gland.  Sometimes attempts are made to pass off the pancreas, ovaries or testes as sweetbreads, but the name belongs to the thymus.

But what is the thymus gland?

In humans, the thymus transforms white blood cells into T-cells.  Once T-cells are produced, they migrate to the lymph nodes, where they will play a role throughout our lives.  These T-cells protect us from viruses and infections, and from their start in the thymus, they protect against auto-immune deficiency.

Interestingly, the thymus gland is only active through puberty.  By then, most of the T-cells have matured and moved into the lymph nodes and the gland will begin to shrink. By our later years, all that remains in it’s place is a small fat nodule.

Sweetbreads

All vertebrates have similar thymus glands. Similar to humans, the thymus gland is only present in young animals – most commonly lamb and veal.  And there is only one set – so sweetbreads aren’t quite as easy to come by as other organs.

They are often referred to in the plural, as the thymus has two connected lobes.  The larger, thicker lobe is commonly referred to as the heart sweetbread and the smaller, uneven lobe as the throat sweetbread.

The whole sweetbread of a calf weighs about a pound. The lamb sweetbread weighs considerably less.  The most recent ones I had were less than a third pound each. However, they are rich and portion sizes can be reduced, or they can be incorporated into larger dishes.

But why are they called sweetbreads?

Marcella Hazan explains, “Bread used to be another way to say morsel, and sweet morsel is an accurate description of this most delectable portion of an animal’s anatomy.”

Wikipedia adds more detail. “Sweet” is perhaps used since the thymus is sweet and rich-tasting, as opposed to savory-tasting muscle flesh. “Bread” may come from brede, “roasted meat” or from the Old English brǣd (“flesh” or “meat”).

I confess that the first time I ate them, I felt tricked and disgusted to learn that my raviolis actually had organ meats in them. The name sounded so alluring.  Doesn’t it?  I would date that back to about 1998. Who would have guessed then what I’d be doing now…

Preparing Sweetbreads

Sweetbread preparations are similar to brains.  First, rinse and soak them. For soaking, one teaspoon of salt per cup of water and an optional squeeze of lemon make a nice bath.  Soaking recommendations vary from 1.5-2 hours to 4-6 hours, as long as the water is changed a few times. (I admit I have left mine overnight before.) This softens the external membrane, making it easier to remove and whitens the gland by extracting blood and impurities.

After rinsing or soaking, the external membrane or large connective pieces can be trimmed or peeled off. Though I find this easier after the gland has been poached. Regardless, stop before (or when) you get to the point where lobes are being separated into small pieces!

If grilling or braising, the sweetbreads can be used as is. For most other recipes, poaching is recommended.

Poach in liquid covering the organ by about two inches – broth, a court bouillon, or simply water with a teaspoon of salt and lemon. Recommendations vary from 2 to 15 minutes. Fergus Henderson suggests to “[t]hink of the finger that pushes the Pillsbury Doughboy’s tummy.  Your finger should push the same way.” They should not be fully cooked through.

After poaching, you can place them in a bath of ice water to cool. Alternately, leave them on a towel on the countertop .

As a final option, place your sweetbreads between two plates and place something very heavy over the top. Leave for 2-3 hours or overnight in the fridge. This will flatten them out (making them easier to cut into narrow slices, if desired) and possibly extract water.

Proceed with your recipe.  Enjoy!