By Zahra Hirji

CELEBRATING the holidays usually involves an abundance of food: cheese platters galore, big Christmas dinners with a centerpiece of turkey or ham or Hanukkah parties overflowing with latkes, and of course piles of cookies, cakes, and other desserts.

“It’s part of our culture,” says Dana Gunders, president of the US-based nonprofit ReFED, which works to reduce food waste. “But I do think there are steps you can take to make sure it’s not wasteful.”

Between 30% and 40% of the US food supply is wasted, according to the Department of Agriculture (USDA). That’s driving climate change, with the Environmental Protection Agency estimating nearly 60% of methane emitted from municipal solid waste landfills comes from decomposing food.

And yet most people underestimate how much food they waste. Multiple surveys in recent years have found that roughly three-fourths of Americans say they waste less than the average person.

“Obviously, that’s not possible,” Roni Neff, a food waste researcher at Johns Hopkins Bloomberg School of Public Health. (The school is supported by Michael Bloomberg, founder and majority owner of Bloomberg LP, parent company of Bloomberg News.)

The good news is there are simple ways to reduce waste. Many of them are focused on being smarter about food safety. Implementing them can help the climate and save money.

With fridges swelling with leftovers, Bloomberg Green reached out to food safety and waste experts to get answers to common questions about how to best handle food and avoid unnecessarily trashing it.

Does the smell test work to determine if food is good to eat or not?

Sniffing food can be useful to check if quality has declined, says Savana Nunn, a food safety expert at North Carolina State University. Other senses can also provide clues: Beyond smelling bad, if food looks moldy or slimy, or tastes bad, experts do not recommend eating it.

But our noses can’t detect the presence of foodborne pathogens such as salmonella that can contaminate food. “Really any foodborne pathogen can infect you where the lowest infectious dose won’t create a scent detectable to a human,” says Ms. Nunn.

Is it ever okay to scrape the mold off something and then eat it? Or, say, if there’s mold on one clementine in a bag or one piece of bread in a loaf, can you toss it and eat the rest?

Some mold makes us sick, some don’t. But the average person can’t easily distinguish between the different types, Ms. Nunn explains.

It’s also important to recognize that mold visible on the surface likely doesn’t represent its full extent. “When a food shows heavy mold growth, ‘root’ threads have invaded it deeply,” warns a USDA mold factsheet. Among the items the agency recommends tossing if mold is visible are bread, cooked pasta, lunch meat, soft cheese, soft fruits and vegetables such as cucumbers and peaches, peanut butter and jams, and yogurts. But there are some exceptions. Hard cheeses and firm fruits and vegetables, such as cabbage and red peppers, are still OK if you cut off at least an inch around and under the moldy spot, per USDA.

How long can you leave something cooked on the counter without it going bad? Does it need to go into the fridge or freezer after cooking?

From roasted meat to simmered vegetable soups to cooked rice, Ms. Nunn recommends getting that prepared food off the stove or the dining table within four hours. But if the temperature is 90°F (32.2°C) or above, it should only be left out of the fridge or freezer for an hour at most, she says.   

Refrigerated leftovers can be OK for up to seven days, Ms. Nunn says, noting her recommendation differs from the more conservative four days recommended by the USDA.

Leaving out food too long can cause pathogens to grow and create harmful endotoxins, explains Ms. Nunn. The endotoxins can also be heat stable, meaning re-heating the food won’t kill them. One example of this is the bacterium Bacillus cereus, which can multiply quickly on pasta and rice at room temperature and produce toxins. While it won’t likely kill you if you’re healthy, the elderly and immunocompromised, “are at a greater risk for suffering complications,” says Ellen Shumaker, director of outreach for North Carolina State University’s food safety program, “and deaths have occurred.”

Is it better to put warm food in the fridge right away or wait until it reaches room temperature?

There’s no need to wait nowadays. Older appliances weren’t as efficient and “putting hot foods in could cause strain on the ability for the fridge to keep everything cold,” Ms. Shumaker says. Today, “refrigerators can handle the warm food going right in,” says Ms. Nunn.

She recommends packing hot things destined for the fridge in shallow containers to help speed up the cooling process and avoiding stacking multiple hot containers on top of one another.

How much worse is it to waste resource-intensive foods? For example, is it worse to waste a pound of steak compared to a pound of broccoli?

It’s “absolutely” worse, according to Ms. Neff. The carbon emissions associated with producing meat, particularly red meat “is far higher than other foods,” she says. Thankfully research also suggests people tend to waste less meat, perhaps because it’s more expensive compared to fruits and vegetables.

Moreover, some modeling suggests that food items with higher water content, such as fruits and vegetables, “are expected to have lower methane generation potential,” explains Minerva Ringland, ReFED’s climate and insights manager.

How long does frozen food stay safe to eat?

Assuming your freezer doesn’t warm up due to a power outage or other issue, it should keep food safe indefinitely, although the quality may decline over time, says Ms. Gunders. She uses her freezer constantly, from stashing bread to packing leftovers before going on a trip. That includes surprise items like milk.

Chefs are developing a growing number of recipes specifically to encourage cooking things without needing to defrost them first, particularly seafood. “The idea is if you buy seafood frozen and you never defrost it, then you’re much less likely to have these issues with worrying if it’s going to go bad and the supermarket’s also going to not have to worry about it going bad,” says Neff. “You can prevent a lot of waste that way.”

Do things high in fat, salt, acid, or other natural preservatives like soy sauce and peanut butter need to be refrigerated? And if not, does refrigerating extend their shelf life?

Refrigerating such products “can definitely extend shelf life,” Ms. Nunn says, by slowing down the growth of spoilage organisms over time. She says the best course of action is to look at a food label and see what the manufacturer recommends. 

Do refrigerator crisper drawers actually keep fruit and vegetables fresher for longer?

In a word, yes. You can control the airflow into crisper draws. It’s best to keep vents open for low-humidity foods, such as apples, pears, melon and most other types of fruit (except berries), Ms. Nunn explains. On the flip side, she recommends closing vents to store high-humidity foods prone to wilting or thin-skinned. Think lettuce, other leafy greens, herbs and cucumbers.

Ms. Nunn also has a tip for extending the freshness of produce left on your countertop. Some fruit, including bananas, produces a hormone called ethylene that induces ripening for anything in its vicinity. So if you don’t want your avocados to ripen too quickly, don’t put them near ripe bananas, Ms. Nunn says. — Bloomberg

THE Center for Culinary Arts Manila (CCA Manila) is helping us out with recipes that utilize holiday party leftovers, for a more efficient (and tasty) New Year.

BEEF CALDERETA TACOS WITH PICKLED VEGETABLES
Yield: six servings

INGREDIENTS:
White vinegar, 120 ml

Water, 60 ml

Sugar, white 10 g

Salt, 5 g

Carrots, julienned 60 g

Eggplant, sliced 50 g

Red onion, sliced 30 g

Tortilla wrap, toasted 6 pcs

Iceberg lettuce, shredded as needed

Leftover beef caldereta, 300 g

Cheddar cheese, 60 g

PROCEDURE:

1. Combine white vinegar, water, sugar and salt in a pot. Let it boil for 3 minutes.

2. Add carrots, eggplant, and onion. Turn off heat.

3. Marinate vegetables for 5-10 minutes. Remove vegetables and set aside.

4. On a tortilla wrap, place shredded lettuce at the bottom.

5. Add beef caldereta, reserved pickled vegetables and cheese on top.

LECHON SOPAS
Yield: four to six servings

INGREDIENTS:
2 cups shredded leftover rotisserie chicken or pork lechon

½ small cabbage, chopped

2 cups small elbow macaroni

1 cup Fiesta Ham, chopped

1 medium carrot diced

3 stalks celery chopped

1 medium yellow onion chopped

2 tablespoons butter

6 cups chicken stock

1 can (340 ml) evaporated milk

Salt and pepper to taste

As accompaniment:

6 pieces pandesal, toasted with grated leftover queso de bola

PROCEDURE:

1. Heat the cooking pot and add butter. Let it melt.

2. Sauté ham, carrot, celery, and onion for 3 minutes or until soft.

3. Put the shredded rotisserie chicken or pork lechon into the pot. Stir and cook for three minutes.

4. Pour chicken broth. Let it boil. Cover the pot and continue to cook in medium heat for at least ten minutes to develop flavors.

5. Add cabbage, and put the elbow macaroni into the pot. Cover and cook until al dente.

6. Pour evaporated milk. Stir. Continue to cook for two minutes.

7. Season with ground black pepper and salt. Serve hot with toasted pandesal and queso de bola.