Case 2: Taking Care of Food After Bringing It Home
Questions I Never Thought to Ask
Living in Italy, there have been many moments when everyday life or problems with my body have made me wonder, ‘Why don’t we learn this at school?’ or ‘Am I the only one who doesn’t know this?’ Or perhaps I just forgot some of what I learned in school.
By researching things for myself and trying them out, I have gradually begun to understand my own body and the way I live a little better. Understanding ourselves better also helps us care for others. In this series, I want to share what I have learnt along the way, from basic knowledge for everyday life to little things I have discovered while living in Italy.
After Coming Home from the Supermarket
When I take vegetables out of the fridge, I sometimes find water collecting at the bottom of the bag. Before I know it, they are slimy or wrinkled. ‘They were so fresh when I bought them, and I even kept them in the fridge. Why have they gone bad so quickly?’
This was one of the first questions after moving to Italy. I had always been interested in choosing ingredients at the supermarket, but when it came to storing them, I had never really thought beyond ‘putting them in the fridge’ or ‘closing the bag’.
Looking into it, I realised that storage matters as much as purchasing. Ingredients need a little care even after we bring them home.
What Causes Food to Change?
At first, I thought of all changes as simply ‘going bad’: a change in colour, softening, or developing mould. But changes that look similar can happen for very different reasons.
For example, vegetables and fruits continue to respire after harvesting. Like cut flowers, they are still alive and affected by their surroundings. Lower temperatures slow down respiration and ripening, but colder is not always better. Some summer vegetables, such as aubergines and cucumbers suffer 'chilling injury' if kept too cold. Different foods need different temperatures and humidity levels.
Enzymes naturally present in food can also change its composition. They enable chemical reactions that ripen and soften fruit or turn a cut apple brown.
Conversely, some food spoilage is caused by the growth of microorganisms like bacteria and mould, while other changes happen because of moisture loss, such as leafy vegetables wilt.
In other words, ‘changing’ and ‘rotting’ are not necessarily the same thing. The gills inside a mushroom naturally darken as it matures, so a dark colour doesn’t mean it is spoilt. However, food with pronounced sliminess, an unpleasant smell, fluffy mould or serious deterioration should not be eaten. Equally, food is not necessarily safe just because it looks and smells normal. Microorganisms that cause food poisoning can be present without producing any visible changes or unusual smells. I realised I must pay attention to my food’s condition while following proper storage methods and use-by dates.
Remove Excess Moisture, but Don’t Let Food Dry Out
In a cheese class, I learnt that a main goal of cheesemaking is to reduce the amount of water in milk. When enough water is there, microorganisms grow, making food control harder. This reminded me of the water at the bottom of my vegetable bags. Mould grows in damp, warm environments with oxygen. It seemed obvious but I had never considered what happens inside those bags. However, we should remove all moisture from vegetables. Leafy greens wilt when they dry out. The goal is preventing dryness while avoiding a build-up of excess water droplets. It is about balance.
For example, I can remove excess surface moisture from leafy vegetables and store them in a bag or container with some kitchen paper. If I wash them first, I need to drain them thoroughly. When the paper becomes soaking wet, I replace it. Rather than closing and forgetting the bag, I check inside occasionally. This was a new habit for me.
The vegetable drawer is not a magical place where food automatically lasts, either. Some are designed to maintain a slightly higher temperature and humidity than the rest of the fridge, but the temperature and mechanism by model. The separate vegetable compartment I used in Japan is not necessarily the same as the drawer in the fridge at my current home in Italy.
What we store next to our food also matters. Ethylene, a gas released by fruits such as apples and bananas, as well as tomatoes, encourages some fruits to ripen, but can also accelerate changes in sensitive vegetables such as leafy greens and broccoli. There is a reason for keeping certain fruits and vegetables apart. Once, I bought some perfectly white mushrooms on a Friday and put them in the fridge in the same paper bag as some tomatoes. When I took them out on Tuesday, the gills underneath had turned rather dark.
On the other hand, if I want a kiwi to soften more quickly, I can leave it alongside a ripe banana or apple. Perhaps storing food is not only about slowing down change, but sometimes about helping it reach the right stage for eating, too.
Does Dry Mean Safe? — Rice, Flour and Pantry Pests
I had started paying more attention to moisture when storing vegetables, but it turned out that keeping food dry didn’t mean it was safe. I found insects getting into my flour, pasta, granola and rice! This raised another question: how could I protect my food from them?
Insects that infest dried foods do not necessarily enter through an open bag. Some may already be present before we buy the food, while others can break through thin packaging or find their way in through tiny gaps. So it is possible to discover insects even in a bag that has never been opened. That is why, once opened, dried foods should be stored in tightly sealed containers made from glass, metal or thick plastic. It also helps to use older products first and avoid buying more than necessary. If I find insects in a food product, I should dispose of it, check the packages nearby, and clean any gaps in the shelves or spilled food. Insects do not spontaneously appear because of heat or moisture. The fly larvae that appear around food waste in summer, and the insects that infest rice or flour, all develop from eggs laid by insects that came from somewhere. Rather than simply thinking, ‘There are insects!’, I needed to consider what they feed on and where they develop. For example, rice weevils lay their eggs inside grains of rice, where the larvae grow. It is not always possible to tell from the outside.
At my family home in Japan, my mother used to keep rice in a large airtight container in a cupboard away from direct sunlight. It was such a familiar sight that I never thought much about it, but now I understand why she did it. There is also a reason for using up the old rice, washing the container and allowing it to dry completely before adding a new batch.
This made me wonder, ‘If sugar, honey and oil contain very little water, does that mean insects won't be attracted to them?’ But making it difficult for microorganisms to grow and preventing insects from being attracted to food are two different things. Ants are attracted to sugar and honey, too. Honey does contain water, but its high sugar concentration means that relatively little of that water is available for microorganisms to use. The degree to which water is available in this way is called ‘water activity’.
Oil doesn’t remain unchanged simply because it contains little water. Exposure to light, heat and air can cause oxidation, changing its flavour. Even among condiments, dried spices, soy sauce, vinegar and jam all have different storage requirements.
Controlling temperature and moisture helps manage microorganisms; suitable containers and clean shelves help prevent insect infestations; and protecting oil from light and air helps slow oxidation. Even though the aim is the same — to stop food from going bad — different problems require different solutions. Even wiping honey off the outside of a jar or cleaning up spilled sugar from a shelf is part of taking care of food.
What Does ‘Room Temperature’ Actually Mean?
In Italian supermarkets, milk and eggs are displayed outside the fridge, even in summer. At first, I was surprised. Some of the milk sold at room temperature is UHT milk, which has been treated at an ultra-high temperature and packaged aseptically. However, even products that can be stored at room temperature while unopened need to be refrigerated once opened. The same goes for eggs. Just because they are displayed at room temperature in a shop does not mean they can be left for a long time in a hot kitchen at home. I want to follow the storage instructions on the packaging, keep them refrigerated at home, and avoid repeatedly taking them out and putting them back, causing temperature fluctuations. I had always assumed that ‘store at room temperature’ meant that even a kitchen reaching 35°C in the middle of summer would be fine. But the conditions on a shelf in an air-conditioned supermarket are different from those in my own home. ‘Room temperature’ does not mean that something can simply be left in a room regardless of the season.
I also began to rethink freezing food.
When I tried to freeze banana bread that I could not finish straight away, or rice I had cooked too much of, some of my friends from other countries found it strange. It was something I had always done, but apparently it wasn’t normal for everyone. Freezing can change the texture of food. But in vegetables and fruits, the ice crystals that form during freezing can damage cell structures, sometimes making certain components easier to release during digestion. And if I divide bread or rice that I will not eat straight away into smaller portions and freeze them, I can take out just what I need later. If I know I will not be able to finish something before going away, I can freeze it before it has a chance to spoil. During the summer, I also became rather fond of peeling ripe bananas, freezing them and adding them to yoghurt. Something I had started doing to preserve food had become one of my favourite ways of eating it.
Of course, freezing cannot rescue everything. It does not make spoiled food safe again, so I need to freeze things while they are still good to eat. For someone like me, who tends to wonder ‘Can I leave this a little longer?’ and then forget about it, that is an important lesson. I had also assumed that curries and stews were safe because they had been thoroughly cooked. But Clostridium perfringens, a bacterium that can cause food poisoning, can multiply when a large pot of cooked food is left to cool slowly at room temperature. So even what happens after cooking matters… Any leftovers should be divided into smaller portions, cooled promptly and refrigerated. I had always thought about reheating food before eating it again, but how I store it beforehand is just as important.
Cheese also needs different treatment depending on whether it is fresh or aged for a long time. When I saw the liquid surrounding mozzarella, I wondered, ‘Should I pour this away, too?’ But, it is not that simple. How to store it after opening depends on the product, so I need to check the instructions on the packaging. I had only just learnt to be careful about excess moisture, and already I had found an exception. Then there is the difference between mould deliberately used in cheesemaking and mould that develops while food is being stored at home. I cannot simply think, ‘Well, cheese is made using mould anyway.’ With soft cheeses, bread and cooked foods, removing only the visible mould may not be enough. Fungal threads may have spread further inside, or mycotoxins may remain. With a hard block of cheese, it may sometimes be acceptable to cut away at least 2.5 cm around and below the mouldy area, but this does not apply to sliced or grated cheese. Even with the same type of food, how it has been prepared or cut can make a difference.
‘Remove moisture.’ ‘Keep it cold.’ ‘Cut off the mould.’ Every time I learn one new thing, I am tempted to think I have found a rule that applies to everything. But each ingredient in front of me has its own particular needs.
When Our Ideas of ‘Normal’ Clash in a Shared House
Once, when I was about to heat something in the microwave covered with cling film, one of my housemates told me, “Don't do that! The plastic will melt!” It was something I had always done in Japan, but when I thought about it, the cling film in front of me was not necessarily the same as the kind I had used back home. Was it microwave-safe? What temperature could it withstand? Was it suitable for direct contact with oily foods? I realised that I needed to check the instructions for each product, including the containers I used.
I had become so accustomed to the incredibly convenient food storage products available in Japan that I had taken them for granted. Meanwhile, at Terra Madre, I heard about how plant leaves are used as plates and food packaging in Taiwan and the Philippines. Someone also remarked to me that “Japan uses a lot of plastic containers.” How can we make food storage convenient without creating excessive packaging? Finding a balance between the two is something I still want to think about.
At first, I also complained about the food waste bags used in Italy: “They leak! They're so flimsy! Why?!” But once I started wondering what material the bags were made from and how they were disposed of, I began to think that perhaps their tendency to tear easily had something to do with being designed to break down. In fact, these bags can be disposed of together with food waste as organico. To understand the purpose of the bags, I also needed to understand how waste is collected and processed locally.
Living with other people has also made me more conscious of moisture left behind in the kitchen, not just in food. Putting wet dishes on top of one another and straight into a cupboard, touching cupboard handles without drying our hands after washing them, or leaving water droplets on the worktop. Dishes do not necessarily have to be dried with a tea towel; they can simply be left to dry thoroughly on a clean drying rack before being put away. Hands should also be dried after washing, and water droplets or dirt left on shared surfaces should be wiped away. A little water left behind does not mean that everything will immediately become covered in mould. But small habits that prevent moisture and dirt from building up help keep a shared space pleasant for everyone. Things I had always considered normal, and things my housemates had always considered normal, began to look a little different once we asked each other why we did them. The kitchen in our shared house has become a place where I find myself thinking about these things every day.
A Little Care After Bringing Food Home
After learning about ultra-processed foods (UPFs), I had been thinking about what I should choose when I went to the supermarket. But for me, an equally significant change was beginning to pay attention to my ingredients after bringing them home. Was there water collecting at the bottom of a bag? Was there anything I needed to eat soon? Was there something I should freeze before going away?
I used to think, ‘It's in the fridge, so it should be fine,’ or ‘I always did it this way in Japan, so it should be fine here, too.’ But little by little, I began to understand the reasons behind things I had previously done without much thought. I also understand a little more now about the things my mother used to do at home. Transferring rice into a storage container or dividing leftover rice into smaller portions was not simply a matter of being tidy and organised after all.
Knowing how to make ingredients last longer does more than reduce waste. It also helps me on days when I am tired and do not feel like cooking. Sometimes, just knowing that there is rice in the freezer is enough to give me a little more motivation to make dinner. And if these small habits mean that I end up throwing less food away, contributing to a more sustainable future, perhaps these everyday actions are also one of the ways I can do something for society.
References
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