5 Secrets of Frugal Grocery Shoppers

Several weeks ago, Robin Shwedo, a documentary producer in Tampa Bay, Fla., was at the grocery store deli when she came across some turkey that looked delicious. She was given a sample, and since she was particularly hungry and thought the turkey tasted wonderful, she bought a pound.

"Two sandwiches later, I decided I didn't want any more of the stuff," Shwedo says. "Half of it went into the garbage."

Shwedo, 60, a widow who shops for herself and two sons, broke the cardinal rule of budget-savvy grocery shopping: Never go to the store hungry. But our appetite isn't the only obstacle to food budgeting. If you've ever seriously tried to manage your food bill, you know how difficult it is to come up with a hard number for the amount you're going to spend at the store and stick to it.

According to the U.S. Department of Agriculture, the cost of feeding a family of four a healthy diet runs between $146 to $289 a week. But even if you decide to spend, say, $800 a month on groceries, that number will likely become obsolete before you know it: Appetites evolve as we age, food prices fluctuate and, of course, given that families don't always eat the same meals over and over, it's simply a challenge to make the math work out during each shopping trip.

[Read: The Secrets to Snagging the Best Discounts.]

But if you're looking for ways to make your food bill more or less a fixed cost, here is a smorgasbord of ideas.

Shop midweek. "According to studies, on Wednesdays, most supermarkets reduce prices on food that is about to expire. This is also the day that the majority of stores start their new sales," says Laura Harders, a mother of two who blogs at BeltwayBargainMom.com, in the Washington, D.C., area.

Odd hours are good, too. In the evenings, "you may be able to save on bakery items that aren't fresh," Harders says. "These items will not likely be sold by the store and will be thrown away or perhaps donated to a local food shelter. If I feel an Italian bread loaf and it is pretty hard, I will ask for a steep discount - 50 to 75 percent off - and then use it for a soggy bread sandwich like Italian Beef or French toast."

And if you show up in the morning, many stores have newly discounted or marked-down items in the produce and meat departments, particularly food that's expiring that day, Harders says.

Grocery shop online. More grocery stores are beginning to offer online shopping and delivery service. Some of the big names are Netgrocer.com, Peapod.com and USGrocer.com, and Wal-Mart and Amazon.com have been testing the grocery delivery waters as well. In 2012, online grocery sales were $6 billion, which sounds like a lot, but that's less than 1 percent of the $850 billion that was spent on food in America, according to a report from the Melbourne, Australia-based research company IBISWorld.

While many people shop online for groceries because it's convenient, it may also be a useful way to shop more carefully. You don't have shoppers with carts behind you, giving you the sense that you should grab your cereal and move on. No one is handing out free samples to entice you to buy something you probably wouldn't have bought otherwise. And it's easier to keep an eye on online shopping cart totals versus adding up prices in your head or on a calculator. Plus, you can easily delete items if you see that you're over budget.

Take technology with you. If shopping online isn't your thing, you can always utilize grocery apps on your smartphone. "There are apps that help save me a ton," says Aimee Brittain, a 35-year-old single mother in Atlanta who runs the blog PrettyFrugalDiva.com.

She has a lot of favorites, but one that stands out is Favado.com, which lets shoppers compare prices of products at local stores to find out exactly where each item is sold the cheapest.

[Read: Could You Cut Your Spending By $1,000 a Month?]

And there are tons of grocery apps designed to help people shop. For example, ZipList helps you with your master list of grocery items, Grocery iQ offers assistance in finding coupons for the food items on your list and Fooducate helps shoppers determine if what they're buying is healthy.

Seek out expired food. Yes, it sounds kind of disgusting, but a recent study by Harvard Law School and the Natural Resources Defense Council found that consumers widely misunderstand expiration dates printed on packaged foods. And you don't need to be told that expired foods are cheaper.

"For most foods, the expiration date is the sell-by date rather than the safe-to-eat date," says Shel Horowitz, a New York City-based author and marketing consultant. "If something is past the [expiration] date, look at how long it's been, how much it's been discounted and what the item is."

Of course, everyone has a tolerance for how fresh they want their food to be, and certainly stay away if an item seems rotten or spoiled. But use common sense. "I have Indian pickles that are years out of date and are still fine," Horowitz says. "For cheese, I'll go up to a week or two, and for dry goods like cereal and crackers, maybe three months."

He draws the line at purchasing or consuming expired milk or yogurt (yes, you'll sometimes find those on the shelves of some stores.)

[See: 10 Saving Strategies That Can Backfire.]

In fact, Horowitz says consumers can get very good deals at deep-discount grocers. "We have a local one here called Deals and Steals," he says.

Quite a few stores specialize in selling safe-to-eat but expired food. In Dorchester, Mass., The Daily Table is opening its doors in early 2014. For decades, Dirty Don's Bargain Center, in Raytown, Mo., has been selling expired groceries. The Dented Can, a longtime presence in Goshen, Ind., has a name that says it all. Scattered throughout the country are hundreds of similar stores, known as salvage grocery stores, that sell food considered unsellable due to damaged packaging or expired dates.

Of course, doing everything you can to save money at the grocery store takes time, and time, of course, is money. In the end, it may come down to what you value more: the minutes on the clock or the numbers in your bank account. Apps and technology, coupons and know-how help, but for now, you still have to invest time to save on thyme.

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