Freshness and quality begin at the farm

Farmers always aim to harvest produce when it’s in optimal condition, but both pre-harvest and post-harvest factors will affect freshness and quality even before you buy it.

Pre-harvest factors are agricultural, such as climatic conditions, soil type and water availability. Post-harvest factors include washing and cleaning after harvesting, transportation and distribution, processing and packaging, and storage.

As consumers, we can’t directly control these factors—sometimes, the veggies we buy just won’t be as good. But we can look out for things that will affect the produce once we bring it home.

One major thing to look out for is bruised, wounded or damaged produce. This can happen at any stage of post-harvest handling and can really speed up the decay of your veggies and fruit.

Moisture loss through damaged skin speeds up deterioration and nutrient loss. The damage also makes it easier for spoilage microbes to get in.

To wash or not to wash?

You don’t need to wash your produce before storing it. A lot of what we buy has already been washed commercially. In fact, if you wash your produce and can’t get it completely dry, the added moisture could speed up decay in the fridge.

But washing produce just before you use it is important to remove dirt and pathogenic bugs.

Don’t use vinegar in your washing water despite what you see on social media. Studies indicate vinegar has no effect on lowering microbial loads on fresh produce.

Similarly, don’t use baking soda. Although there’s some evidence that baking soda can remove pesticide residues from the surface of some produce, it’s not advisable at home. Just use plain tap water.

Location, location, location

The main thing you need is the correct type of packaging and the correct location – you want to manage moisture loss, decay and ripening.

The three main storage options are on the counter, in the fridge, or in a “cool, dry and dark place”, such as the pantry. Here are some common examples of produce and where best to put them.

Bananas, onion, garlic, potatoes, sweet potato and whole pumpkin, will do better in a dark pantry or cupboard. Don’t store potatoes and onions together: onions produce a gas called ethylene that makes potatoes spoil quicker, while the high moisture in potatoes spoils onions.

In fact, don’t store fruits such as apples, pears, avocados, and bananas together because they release ethylene gas as they ripen, making nearby fruits ripen (and potentially spoil) much faster. That is unless you do want to ripen your fruits fast.

All leafy greens, carrots, cucumbers, cauliflower, and broccoli do best in the fridge’s low-humidity drawer (crisper). You can put them in perforated plastic bags to retain moisture but maintain airflow. But don’t put them in completely sealed bags. This can slow down ripening while trapping carbon dioxide, leading to decay and bad smells.

Some fruits will also do best in the fridge. For example, apples and citrus fruits such as oranges can keep fresh longer in the fridge (crisper drawer), although they can stay at room temperature for short periods. However, don’t store watermelon in the fridge for too long, as it will lose its flavour and deep red colour if kept refrigerated for longer than three days.

Most herbs and some leafy vegetables – like celery, spring onions and asparagus – can be kept with stems in water to keep them crisp. Keep them in a well-ventilated area and away from direct sunlight so they don’t get too warm and wilt.