Master the Art of Food Expiration Dates: Tips and Tricks

As we navigate our weekend errands, many of us find ourselves scrutinizing the expiration dates stamped on product packaging. But do we really understand the difference between ‘use by date’ and ‘best before’? Knowing this can help us make better choices about the products we buy.

This concise guide explains the differences in food labeling and gives practical suggestions on how to preserve the freshness of products, maximize the taste, and minimize waste.

Understanding food expiration labels

The description of a food label can vary depending on the country. It is important to interpret the labels used by the producers to preserve the freshness of the products and minimize waste. While no uniform labeling exists between the countries, the USDA food safety guidelines provide indications for retailers and customers.

Sell by

The 'Sell by' label indicates how long the product can be displayed for sale. This data helps retailers manage their stock and ensure they give their clients sufficient time to purchase before the product goes wrong.

Use by

The 'Use by' label marks the date by which a product should be consumed, cooked, or processed safely. It's especially crucial for perishable items like meat or dairy, where consuming them after the expiration date could pose health risks.

Best before

This label indicates when the product will be at its best quality. After this time, food quality might decrease, accompanied by possible taste and texture changes. The food might still be safe to consume.

Safety first: health risks of ignored expiration dates

The expired food might lose nutritional value, which is important to our health. However, consuming expired products can also lead to more severe consequences. The potential health risks include mild digestive discomfort, with symptoms such as bloating, gas, or indigestion. The more serious risks are associated with food poisoning, also known as foodborne illnesses caused by bacteria such as Salmonella, Staphylococcus aureus, or Escherichia coli. The results of food poisoning might include, among others, vomiting, diarrhea, and fever.

Certain foods can become particularly hazardous after their expiration date. This includes dairy products, such as milk, yogurt, or kefir, and soft cheese (e.g., ricotta and mozzarella). You should avoid eating meat and fish after their expiration, especially meat that is eaten raw (e.g., carpaccio, sashimi). Leafy greens such as kale or spinach are also not recommended as they can be a reservoir of bacteria during their decomposition process.

The science behind expiration dates

The method of determining the expiration date of products might depend on national legislation. The USDA guidelines explain that companies determine the expiration dates of their products considering several factors, such as the length of time and the temperature at which food will be held during transportation and storage. Other variables include the type of food or the packaging in which the product is enveloped.

Light, temperature, and humidity might speed up food spoilage. LED or UV light induces chemical reactions in vegetables, which might lead to discoloration and vitamin loss. It is important to maintain temperature control as an increase can accelerate the growth of microorganisms, which makes food deteriorate faster. Similarly, high humidity promotes bacterial growth and accelerates chemical reactions occurring in food, leading to faster spoilage.

How to properly store food to extend shelf life

To ensure food safety, it should be stored appropriately, in the right place, and using appropriate packaging. Below, we present tips on how to extend the shelf life of your groceries:

• Refrigerate. It is the universal way to preserve the freshness of perishable goods such as meat, fish, dairy, certain vegetables, or some non-perishable foods (e.g., nuts). Storing food in your fridge, which should be set at 2–4 ºC (35–40 ºF), slows the growth of bacteria, fungi, and mold, which are leading causes of food spoilage. Use different compartments of your fridge for different foods. Put vegetables in the crisper and store dairy on the shelves, which provides a more stable temperature. Aim to put the items that are about to expire in the front, remember to consume them first, and clean your fridge regularly to prevent bad smells and the spread of bacteria.
• Freeze. This is an excellent way to stock up on meats or fish for an extended period. It can also extend the freshness of bread or other baked foods. Frozen food can be used for 6–12 months, which can be extended if stored in vacuum packaging. The ideal temperature for a freezer is approximately -20 ºC (-4 ºF). To preserve the freshness of the products, freeze them at peak quality in containers to prevent frost accumulation. Labeling with date will help you track how long the food was stored.
• Dry storage. This way of keeping food is especially useful for pantry items, including canned goods, grains, pasta, and spices. Store the items in dry and dark places away from direct sunlight to avoid food spoilage. Use sealed containers to prevent humidity and extend shelf life. Dedicate a cupboard or space for exclusively food storage, keeping the products away from clearing supplies and other chemicals. Remember to check the pantry regularly and use the about-to-expire products first.

Using your senses: when to trust food over the label

While the labels provide information about the expiry date, it is always good to use your senses to ensure that the food is good for consumption. You might use the following tips:

• Check for color changes. Vegetables going brown or meat turning greenish might indicate food spoilage.
• Look for mold. An unusual whitish color on the dairy and bread might be a sign of mold.
• Check the texture. Changes in texture, like unusual sliminess or softness, might indicate bacterial growth.
• Use your smell. The off or rancid smell likely indicates that the food has started to degrade.
• Taste a small amount. If food tastes different than usual, it is better to discard it.

Some foods are safer to eat beyond the date marked on the label than others. Pantry items such as canned or dry food are often safe beyond the expiry date if stored properly. This also applies to condiments (e.g., ketchup, mayo) or hard cheeses (e.g., parmesan).

Perishable goods such as meat, seafood, soft cheeses (e.g., mozzarella), or other dairy products are high-risk foods prone to bacterial growth. Consuming these after the expiry date is not recommended unless their freshness is preserved (e.g., freezing).

Overall, understanding food expiration dates can help make safer decisions about food consumption, maximize product freshness, and minimize waste. Applying information regarding the storage of the goods, incorporating appropriate packing, and using your senses while assessing the condition of the food are helpful ways to ensure that the food is of the best quality while reducing the risk of foodborne illness.