20 Items Not to Buy in Bulk: Beer, Soda, Diapers, and More

Big Mistakes

These days people are stocking up more than ever (especially on toilet paper) but it's critical to do it the right way. Shopping at a warehouse club like Costco or Sam's Club can save you a ton, but it can also be an exercise in frustration. What's going to go bad before you can use it all? Which items might be cheaper during your usual grocery run? To help, we've compiled a list of products that may not always be better to buy in bulk, even in a crisis.

Beer

Unlike wine, beer doesn't get better with age. Most brews have a lifespan of three to six months, depending on what kind of beer it is, its alcohol content, how it's packed, and whether it's been refrigerated or kept at room temperature. Beer that's past its prime won't kill you, but it won't taste very good, either. Beer Connoisseur magazine recommends drinking craft beers like pale ales and lagers within three months, while porters, stouts, high-alcohol brews like imperial pale ales can keep for four or five months if refrigerated.

Diet Soda

Prefer to stick with soda? This might be another beverage to resist stockpiling, especially if you drink diet soft drinks. Real Simple says you only have a few months after the "best by" date before quality starts to decline.

Produce

It may seem like a no-brainer, but it bears repeating: Unless you're buying for a truly large family or special event, lots of fresh produce will be hard to use before it spoils. And as consumer advocate and radio host Clark Howard advises, in-season produce is probably cheaper at your local grocery — and available in more manageable quantities, to boot.

Laundry Detergent

That mega-size bottle of laundry detergent is probably a tempting buy, but hold off unless you really do a lot of laundry. Whether you prefer liquid or powder detergents, they typically only retain all of their cleaning power for six months to a year, according to Good Housekeeping. After that, they start to lose their effectiveness.

Dishwasher Detergent

The news is even worse for dishwasher detergent: You'll only get about three months of peak effectiveness, says Good Housekeeping. If you prefer to wash your dishes by hand, you'll get a much longer detergent lifespan of up to 18 months from regular dish soap.

Liquid and Cream Eye Makeup

Skip any multipacks of mascara and liquid eyeliners, both of which can go bad in just three months, according to Good Housekeeping. Cream eye shadows have only six months. Bulk buys are safer for powder eye shadows and pencil liners, which are good up to two years.

Sunscreen

Notoriously pricey sunscreen can be a tempting bulk buy, but be careful to store it in a cool environment. That's because the ingredients that protect us from the sun's harmful rays can actually start to break down in the heat, which could leave you burnt even after slathering on the sunscreen.

Bleach

Unless you go through a lot of bleach (maybe a little more likely now), buying that jumbo-size bottle probably isn't the best move. Real Simple says it's effective only up to six months. Clorox notes that the active ingredient, sodium hypochlorite, naturally breaks down, especially in extreme temperatures. Even bleach that's always kept at room temperature should be replaced after a year, the company advises.

Diapers

Diapers are a risky bulk buy because babies grow so fast. A sudden growth spurt could render that massive case of Size 1s useless, while an early potty trainee might suddenly say bye-bye to a fresh case of Size 4s. Diapers may also be available elsewhere for less. For example, a Cheapism price comparison once showed Amazon had lower prices on Huggies than Costco, and that's without accounting for additional Amazon Family discounts.

Probiotics

While most vitamins and dietary supplements can last quite a while — roughly two years, according to The New York Times — the same isn't the case for probiotics. You'll only about a year before they should be pitched, and take note of storage instructions: Some will require refrigeration.

Skincare Products

Many skincare products have a short shelf life. The worst offenders, according to Allure: hydroquinone creams used for lightening age spots and freckles (2-3 months); peels and masks (3 months); acne treatments (4-6 months); and skin-perfecting retinoid creams (9-11 months). Also, be wary of anything sold in a jar: Dipping in repeatedly exposes the product to more air, light, and bacteria, experts tell The New York Times.

Whole Grains

That massive bag of brown rice or quinoa may seem like a healthy, budget-friendly buy, but whole grains don't stay fresh as long as their processed counterparts. Intact whole grains will last up to six months in an air-tight container in the pantry, advises the Whole Grains Council. Whole grain flours and meals only keep up to a few months.

Cereal

Price is the biggest consideration here. Cereal is one of the most popular items on supermarket shelves, which means you can snag great deals because sales are frequent, according to Clark Howard. Of course, you also need to consider freshness before buying in bulk — no one likes stale Cheerios. And once opened, that massive box of cereal will start going stale in two or three months, according to Still Tasty.

Related: Pie Crust and Other Delicious Uses for Cereal Besides Breakfast

Coffee

The general rule of thumb, whether you buy your coffee at Costco or the corner roaster's, is this: Whole beans last longer than ground coffee. Unopened, a bag of beans will last from 6 to 9 months, in some cases up to a year depending on how its stored, and ground coffee will last for a few months. Assuming you grind your beans daily and keep the rest stored properly, you can keep them in the pantry for quite awhile. But if you bought a 5-pound container of ground Colombian coffee, the freshness clock starts ticking as soon as you open it. The San Francisco Bay Coffee Co., which is sold at Costco and other big-box stores, recommends keeping ground coffee in a non-refrigerated, airtight container and using it as quickly as possible. The longer it sits around, the more flavor it will lose. If you love instant coffee, then go right ahead and stock up. The freeze-dried stuff will last up to 20 years unopened.

Spices

True, that institutional-sized container of cinnamon looks (and smells) enticing. But unless you bake on a daily basis, you're far better off buying regular-sized containers of spices, according to McCormick and Co. Ground spices and dried herbs will last up to three years and whole spices up to four, but a seasoning blend will only last for a year. Once your spices have passed their best-by date, they won't turn rancid or otherwise go bad. Their flavor and aroma will be past their peak, however. Exposure to humidity, heat, or sunlight will also compromise flavor.

Condiments

Just about any bottle of ketchup, mustard, or mayonnaise is going to be stamped with an expiration or "best by" date, and as far as the manufacturers are concerned you shouldn't be consuming them if they're past that date. If a bottle of ketchup has been stored unopened in a cool, dry pantry, and you open it one day past its "best by" date, it will still be safe to eat. But that ketchup — any ketchup, really — will only last for six months once it's been opened and kept refrigerated. Freshly made salsa lasts just one week, but mustard can last a whole year. Not sure if your Labor Day condiments will make it to next year? Check out FoodSafety.gov's Foodkeeper app for more food data.

OTC Medications

Aspirin, ibuprofen, decongestants, and other over-the-counter medications are required by law to carry an expiration date. But all that indicates is how long the manufacturer can guarantee their full effectiveness. In other words, if you have a stuffy head and you take a decongestant that's six months past its expiration date, you'll still experience some degree of relief. However, you also have to be realistic about how frequently you and your family use OTC meds and whether it's wise to buy a year's worth of antihistamines just because you can.

Baking Powder and Flour — Dubravina/istockphoto

Baking Powder and Whole Wheat Flour

You'll need to be a busy baker if you intend to use every last scoop of bulk baking goods such as baking powder. It only has a shelf life of about nine months. All-purpose flour lasts about a year if kept in an air-tight container, but whole wheat flour only lasts one to three months. The difference? Whole wheat flour still contains trace amounts of oil from the germ that can oxidize and spoil if not stored properly.

Canned Fruits and Vegetables

Canned foods can last for up to five years as long as they remain sealed and stored in a stable environment, according to the U.S. Department of Agriculture. But shelf life depends on the kind of food inside the can. Tomatoes, pineapple, and other high-acid foods only last 12 to 18 months; low-acid foods like tuna or most vegetables, can last three to five years. There's also the matter of keeping the leftover food fresh once you've opened the can. The USDA says low-acid foods only last about a week in the refrigerator; high-acid foods are good for just two or three days.

Toilet Paper

Aside from the fact that you'll need a lot of storage space for the massive packs of toilet paper found at your local warehouse club, sometimes you won't save compared with other stores. Money found that toilet paper costs a whopping 74.9 cents per roll at Costco, while it only costs 15.3 cents per roll at Walmart. You can also use manufacturer's coupons for an even better deal at the grocery, unlike Sam's and Costco, which prohibit them.