Meal prepping: benefits and risks – and the key role played by drinking water

When juggling work, appointments and household chores, there’s often very little time left to prepare a meal from scratch. So, many of us settle for fast food or whatever we can find in the fridge. Meal prepping: all the rage – and a good alternative? Meal prepping (or ‘meal prep’ for short), refers to the planned preparation of meals, whether just for tomorrow or for a whole week at a time. But how safe are these ‘prepped’ meals from a microbiological perspective? What are the risks in relation to shelf life and food hygiene? And what role does drinking water have to play here?

The practical benefits of meal prepping
Meal prep and microbiological risks
Water has a shelf life
Safe meal prepping – what you need to know

Benefits of meal prepping

There are many benefits to planning and preparing meals. Preparing a large volume of food in one go saves time and money while also simplifying the daily routine – especially for busy professionals. Instead of having to rely on expensive ready meals or spending time in the kitchen after finishing work, the pre-cooked meals can simply be re-heated and eaten. And this conscious preparation of balanced meals or snacks has another advantage: it supports and promotes a healthy diet.

Meal prep and microbiological risks

Food hygiene risks are always present wherever and whenever foods are processed, stored or consumed. Alongside general good hygiene practice, the following specific aspects should also be considered to avoid microbiological risks.

Contamination during preparation

The preparation of foodstuffs harbours a risk of ‘cross contamination’, i.e. the transfer of harmful bacteria from one type of food to another. Especially when handling raw meat or eggs, there is a significant risk that pathogenic organisms like Salmonella may be present in the food. Alongside thorough cleaning – which includes washing the hands and kitchen utensils – it is therefore important to store and process raw and cooked food separately.

Incorrect storage

Taking an overly careless approach to storing the prepped meals can allow harmful bacteria to propagate rapidly in the food. To avoid this, storing the meals in a cool and dry place is a must – and the use of air-tight containers is another essential requirement. Once prepped, the meals can be stored safely in the fridge for about 3 or 4 days. If meals are to be kept for longer, they should be stored in the freezer, where they will keep for up to 12 months.

Problems when storing in water

Apart from making complete, pre-cooked meals, meal prepping also involves the targeted preparation of individual ingredients like fresh fruit and vegetables. According to viral videos doing the rounds on social media, fruit and vegetables can be peeled, pre-cut and then stored ready to use in containers filled with tap water. From a microbiological perspective, however, this is a recipe for disaster. First of all, the peeled foodstuffs will be contaminated by contact with the hands and these bacteria will multiply in the water. The pre-cut foods will also release a lot of nutrients into the water, thereby enriching it for the bacteria while losing both flavour and quality themselves. Celebrity chef Tim Maelzer once got the chance to see what this looks like under the microscope: biologist Rainer Wegerhoff sliced up some salad leaves and then impressively demonstrated how the cellular fluid promotes the growth of putrefactive bacteria.

GRANDIS-E — GRANDIS E hybrid kitchen tap

Water has a shelf life

Water plays a key role in our nutrition. We drink it and use it during cooking – whether for washing ingredients or when preparing a wide variety of meals. Yet we often forget that drinking water, like any other foodstuff, also has a shelf life. This makes it all the more important to check the quality of the water and handle it correctly. According to the German Federal Environment Agency, water that is used to prepare food or consumed directly should not have been left standing in the drinking water installation for longer than four hours. If this rule is followed, water remains a wonderful and sustainable foodstuff. Unlike bottled water, tap water does not create any harmful greenhouse gas emissions from transportation, nor is it decanted into plastic bottles that end up as microplastics at the end of their useful life.

If you want to use tap water for drinking or cooking, you can use the simple ‘back of the hand’ test. Fresh water will feel cool to the touch – so let the water run out of the tap until it starts getting cold.

Practical tips for safe meal prepping

Handle each foodstuff correctly: Maintain the cold chain, check the shelf life, and avoid cross contamination between raw meat or eggs and other foods.
Do the sniff test! Any food that smells unusual is usually best discarded rather than eaten. If a food still looks and smells good despite being past its expiry date, you can go ahead and eat it, but it’s best not to store it for any longer once opened.
Hygiene is the golden rule: wash your hands thoroughly, clean and disinfect work surfaces, kitchen appliances and cooking utensils, and change/launder hand towels – as well as sponges and cloths – at regular intervals.
Store your prepped meals properly: in a cool and dry place in airtight containers, and don’t keep meals in the fridge for longer than 3–4 days.
Keep water quality in mind: Do not let water stand for longer than 4 hours before consumption and ensure regular use/flushing of all tapping points.

Meal prepping can be a healthy and practical way to achieve a more efficient daily schedule while also supporting a balanced diet. However, basic hygiene aspects do need to be borne in mind to avoid some inherent microbiological risks. Hygienic preparation, correct storage and remembering that water is (also) perishable are all-important when it comes to ensuring that the prepped meals not only taste fantastic but are also completely safe to consume.