Several snow days deep this winter, there’s got to be something to sip besides coffee and wine while on the mend from shoveling. Consider what some home cooks and chefs make to stay warm and at least feel healthy: bone broth.

Now, the kind of bone broth that’s been taking over on-trend kitchens in the past year or so differs from stock in a few ways. First, it’s made with an acid like vinegar, which hard-core drinkers say draws out more nutrients. Second, it’s cooked way longer than stock is, up to a day or two. Finally, it’s meant to be consumed by itself, as you would a consommé.

Broth has been in many cuisines for centuries. If you didn’t grow up drinking the homemade kind, maybe you’ve gotten a taste for it from Allston’s Seoul Soulongtang (slogan, “Beef soup for the soul”) or Somerville’s Backbar, where those in the know sit down for pork- or chicken-broth ramen at select hours. It’s only a matter of time before Boston’s entrepreneurs mimic New York City’s Brodo, where through a tiny window, you get eight ounces of a chicken-turkey-beef hybrid broth from local, grass-fed animals for $4.50.

But you can make quarts of broth at home for much, much less, even if you’re buying the bones of pasture-raised animals at Somerville butcher M.F. Dulock.

"Every meat we offer, we sell the bones," said co-owner Michael Dulock.

Beef knuckle bones go for $4/lb and marrow bones for $6/lb. Five-pound bags of chicken bones are available for $15 on Wednesdays, if you ask ahead.

"We have to encourage our guests to use the whole animal," Dulock said. "At home we’ve figured out how to use everything."

Dulock's recipe for bone broth of any sort is simple: put the bones in a pot, cover them with water, simmer for eight hours, strain, and add a pinch of salt.

"This is one of those things where if you have the day off, you put it on and walk away."

Another Boston-area purveyor for broth bones is The Butcher Shop, a meat seller and wine bar in the South End.

"We generate bones hourly as we butcher here, but they generally go right in the oven because we make stock every night," said Chef de Cuisine Matt Mahoney.

But if you put in an order for bones a day in advance, they’ll save them raw—not roasted.

"You’re not going to get the most body if you roast the bones," he said. "If you’re looking for a deep color and a caramelized sugar and protein flavor, you’ll roast the vegetables."

See Mahoney’s recipe for broth, as well as a map of other places to buy bones, below.

For a viscous beef broth like Vietnamese pho, Mahoney suggested using part of the rib cage and a shank joint, or a section of the spine, for the gelatin and collagen inside.

"You also want something that has a little bit of meat stuck to it," he said. "Bone has flavor, but if there isn’t meat clinging to the bone, you’re not going to maximize beefy flavor."

While marrow bones make thick broth, Mahoney warned against using too many because they’ll turn it greasy. And if you’re into broth more for its flavor than its touted health benefits, he suggested simmering chicken bones for no longer than six hours and lamb or beef no longer than 10.

"Going any further than that is going to produce a muddled flavor," he said.

About those touted health benefits: Simin Nikbin Meydani, the director of Tufts University’s Human Nutrition Research Center on Aging and a regular beef-broth maker, hasn’t seen scientific backing for bone broth being remarkably nutritious or superior to other soup. (She's not the only skeptic, as NPR's The Salt blog  recently pointed out.)

"Yes, the bone has calcium; yes, there’s collagen, but once you consume it, collagen is broken down into amino acids," Meydani said. "There is the bone marrow—calorie dense, but I wouldn’t say it’s a rich source of protein."

The Butcher Shop Chef de Cuisine Matt Mahoney’s recipe for bone broth

3 pounds of unroasted bones

2 Tbs cider vinegar

3 carrots  

2 yellow onions

3 celery stalks

1 head of garlic or 1 leek, optional

10 peppercorns

1 bay leaf

A few parsley stems

Salt

1. Fill an 8-12 quart pot with the bones and cold water.

2. Bring to a simmer and then drain the water. This will remove much of the unwanted blood and impurities. 

3. Fill pot again with cold water to cover bones by two inches, along with vinegar, and bring back to a simmer. Allow to bubble gently for 6-12 hours (6 for poultry and closer to 12 for veal or beef). Skim any foam or fat as needed with a ladle. 

4. While stock is simmering, roast carrots, onions and celery stalks. You may include garlic or leeks, but be aware that the flavor will reflect this decision. 

5. For the last hour of cooking, include the roasted vegetables, 10 peppercorns, 1 bay leaf, and a few parsley stems. Adding these at the end of the stock-making process achieves maximum aromatic qualities. 

6. Strain, season with salt, and allow to cool at room temperature for one hour before skimming the fat from the surface, and then refrigerate until cold. From here you can freeze in Tupperware or Ziploc bags and pull out to thaw as needed.

Want to make your own broth? Here’s a map of Greater Boston butchers and grocers where you can buy meat or poultry bones.

Have a go-to butcher that’s not on the map, or want to share your bone-broth recipe? Add it in the comments section below.