As the UK braces for a heatwave with temperatures soaring to 32°C (90°F), many people are preparing for outdoor BBQs, picnics, and al fresco dining. However, as the mercury rises, it’s important to reconsider how you store your food. While we often store certain items in the kitchen cupboard, experts advise that some of these foods should be moved to the fridge during extreme heat to prevent the growth of harmful bacteria and avoid spoilage.

Earlier today, forecasters announced that Britain will enjoy temperatures of up to 32°C this week as some places will be hotter than parts of southern Europe

In this article, we will explore the key foods that need to be refrigerated during the heatwave, and why doing so can significantly reduce the risk of foodborne illnesses. Additionally, we will highlight general food safety practices to ensure your meals are safe and enjoyable despite the high temperatures.

The combination of high temperatures and improper food handling can create an ideal environment for rapid bacteria growth, which poses a serious health risk, experts said (stock image)

Why Is Food Storage Crucial During a Heatwave?

During periods of extreme heat, food safety becomes an urgent issue. The combination of high temperatures and improper food handling creates an ideal environment for bacteria to grow rapidly. According to Rachael Kiss from Alliance Online, "Periods of extreme heat increase the risks associated with improper food handling." Even small lapses in food hygiene can lead to significant health risks. That’s why it’s essential to adjust your food storage habits to ensure that your meals remain safe, especially in the heat of summer.

1. Ketchup: A Condiment That Needs Refrigeration

Ketchup is a staple in many homes and is usually stored in the cupboard or on the table. However, experts now warn that during hot weather, it’s better to store ketchup in the fridge to prevent the growth of bacteria. "Even small lapses in food hygiene can have significant consequences in warm weather," Kiss explained.

Ketchup, which should regularly be kept at room temperature, should be moved to the fridge during a heatwave - along with other condiments

While ketchup may typically be fine at room temperature, the heat can accelerate bacterial growth, potentially making it unsafe. The combination of sugar, vinegar, and spices in ketchup can attract harmful microbes, particularly during periods of high humidity and heat. To extend its shelf life and avoid foodborne illnesses, it’s best to refrigerate your ketchup during the heatwave.

2. Peanut Butter: Why It Should Be Refrigerated

Peanut butter is another food commonly found in kitchen cupboards, but it is also susceptible to spoilage in the heat. "Peanut butter can go rancid faster in the heat," said experts. The oils in peanut butter are sensitive to temperature fluctuations, and when exposed to high temperatures, they can break down and become rancid, leading to unpleasant flavors and potential health risks.

Peanut butter – a breakfast staple that many keep in their kitchen cupboard – should be put in the fridge as it can go rancid faster in the heat, experts said

To preserve the quality and safety of your peanut butter, store it in the fridge during hot weather. This will prevent the oils from going bad and keep the peanut butter fresh longer. While refrigeration may cause some natural separation of oils, simply stirring the peanut butter before use can restore its consistency.

3. Chocolate: Why You Should Keep It Cool

Chocolate, a beloved treat, is another food that can be affected by high temperatures. During a heatwave, chocolate can easily melt and develop a whitish film, known as "bloom," when it cools again. This is due to the cocoa butter separating from the rest of the chocolate. While the bloom doesn’t make the chocolate unsafe to eat, it can affect the taste and texture.

Bars of chocolate, which some may prefer to store at room temperature, should be moved to cooler temperatures to stop it spoiling

To avoid these issues, it's best to store chocolate in a cool environment, such as the fridge. Although refrigeration can cause some changes in texture, it will help preserve the chocolate’s integrity and prevent it from melting during the heatwave. Remember to let the chocolate come to room temperature before eating to avoid the cold, hard texture from refrigeration.

4. Bread: The Battle Between Freshness and Mould

Storing bread in the fridge is often controversial, as it can cause the bread to go stale faster due to the refrigeration process. However, in extremely hot weather, the risk of mold growth increases, and bread may spoil faster than usual in the cupboard. Mold thrives in warm, humid conditions, making the heatwave the perfect environment for it to grow.

“If you’re worried about your bread going mouldy, putting it in the fridge could be a better option than leaving it in a warm cupboard,” Kiss advised. If you prefer your bread to stay fresh and soft, consider freezing portions and defrosting them as needed. This will help maintain the bread’s texture while preventing spoilage in the heat.

Although storing bread in the fridge (as pictured here) can make it go stale faster, it may be better than it going mouldy in the cupboard, Ms Kiss said

5. Fruit: Why Certain Types Need Refrigeration

Certain fruits, especially berries, are highly perishable and spoil quickly in warm temperatures. “Fruits like berries should be placed in the fridge,” experts recommend. Berries, such as strawberries, raspberries, and blueberries, are particularly vulnerable to rapid deterioration due to their high water content and delicate skins. Leaving them out in the heat can cause them to spoil within a day.

Additionally, stone fruits like peaches and nectarines can ripen too quickly in hot weather. This accelerated ripening process can lead to overripe or spoiled fruit in a matter of hours. To extend the shelf life of these fruits, store them in the fridge until you're ready to eat them. For fruits that ripen quickly, like peaches, refrigeration can slow down the ripening process and keep them fresh longer.

While peaches are regularly kept in a fruit bowl, they can ripen too quickly in the heat and should be moved to the fridge

6. Sauces and Spreads: Keep Them Cool

Many condiments, such as mustard, jam, and mayonnaise, are usually stored in the cupboard or on the kitchen counter. However, during high temperatures, even these shelf-stable condiments can become susceptible to bacterial growth. Experts recommend refrigerating opened sauces and spreads, including ketchup, mustard, and jam, to maintain their safety.

Dr. Rachael Kiss emphasizes that "condiments last longer in the fridge during warm weather," as refrigeration helps to preserve their quality and prevent the growth of harmful bacteria. Even unopened jars of sauce may benefit from being stored in the fridge, especially in very hot conditions. While some sauces, like mustard, may still be fine at room temperature, it’s always safer to err on the side of caution and keep them cool during extreme heat.

7. Cakes and Pastries with Cream or Icing

Cakes and pastries, particularly those with cream or icing, are highly susceptible to spoilage in warm weather. "Cakes and pastries with cream or icing are much more prone to spoilage," Kiss warns. These sweet treats can quickly develop bacterial growth due to the perishable nature of their ingredients.

Cakes and pastries with cream or icing – which are much more prone to spoilage – should also be stored in the fridge

To ensure that cakes and pastries stay fresh and safe to eat, they should be stored in the fridge during hot weather. This is especially important if they contain perishable fillings or frosting. Refrigerating cakes and pastries will prevent them from going off and reduce the risk of foodborne illnesses associated with spoiled ingredients.

General Food Safety Tips During Hot Weather

In addition to adjusting your food storage habits, there are several general food safety tips you should follow during a heatwave to protect yourself and your family from foodborne illnesses:

• Use insulated bags or cool boxes when shopping for chilled or frozen items, and never leave groceries in a hot car for extended periods.
• Check appliance thermometers to ensure that your fridge is operating at 5°C (41°F) and your freezer is at -18°C (0°F) to keep food at the proper temperature.
• Don’t leave perishable foods at room temperature for more than two hours, or just one hour if the temperature exceeds 32°C (90°F).
• Be cautious with outdoor meals, such as BBQs or picnics. Ensure that meats are cooked to the correct temperature, and avoid leaving food out in the sun for too long.
• Keep raw and cooked foods separate during preparation to avoid cross-contamination, and always use separate utensils and cutting boards for different types of food.

The Impact of High Temperatures on Health and Food Safety

As Britain prepares for a heatwave, forecasters predict temperatures will rise as high as 32°C (90°F) in some parts of the country. This heatwave means that some areas of the UK will experience temperatures higher than those found in popular southern European destinations like Lisbon and Barcelona. In these conditions, food safety becomes even more critical.

Experts from Which? previously revealed the correct spot for every single item in your fridge (not during a heatwave) including raw meat, leftovers, and condiments

Experts urge that the combination of high temperatures and improper food handling can create the perfect environment for bacterial growth, making it essential to store perishable foods in the fridge and follow safe food preparation practices. Following these precautions can prevent foodborne illnesses and ensure that you enjoy your summer meals without any health risks.

Conclusion: A Summer Food Safety Refresh

With the rising temperatures and the potential for bacteria growth in the heat, it’s essential to adjust your food storage practices to ensure your meals remain safe and enjoyable. Moving certain foods—such as ketchup, peanut butter, chocolate, and cakes—to the fridge is a simple yet effective way to prevent spoilage and reduce the risk of foodborne illnesses. By following expert advice and keeping your kitchen organized, you can enjoy a safe and delicious summer, no matter how hot it gets outside.