First we have to understand what causes your food to lose its crispiness. It's moisture. Your food gets moisture from the surrounding and it makes that crackers or biscuits become soggy in a way, losing its crisp and crunch.

So, in order to keep the food's crunchiness, and freshness, the main thing is to keep the moisture out.

Let us share some of the industry best practices with you so that you can move on to deciding the best way to prolong the crispiness in your food like a professional.

Keeping in an airtight container

This is an age old myth that is as true as it gets. The protection against moisture with the normal plastic bag that your food comes in will be compromised once the packaging is opened.

Even if the packaging comes in a resealable zipper, it will be ideal to keep the food (including the packaging, do not take it out from the bag!) inside an airtight container. The trick is to get a container that is as close to the size of your packaging as possible. This is because the packaging will take up space in the container, leaving air (and moisture) with lesser space when you close the lid.

In this way, your food will be "double protected" against new moisture entering the space of the food, making it last longer than as compared to leaving it out in an open environment.

Not In The Fridge

Contrary to popular belief, the refrigerator is one of the worst place to have your food in when you want to keep its crispiness.

It helps to keep it from turning bad, no doubt, but keeping your crackers crunchy is another thing altogether. The fridge has low temperature to keep bacteria from multiplying and is a very moist environment that can hit up to above relative humidity of 90% at times!

To note that 100% RH means water, this means trouble if water vapour in the air is something we want to keep out.

Even if you must, consider including a desiccant (will be talked about below) or even a roll of toilet/tissue paper to absorb the unnecessary moisture in the air to try preventing your food from turning soggy.

Aluminium Bags

Aluminium bags or moisture barrier bags have much higher level of defense against the emission of moisture from the environment as they are less porous than the normal LDPE / HDPE (or layman term: plastic) bags you see being used in most food packaging.

As they are relatively much more expensive than normal plastic, they are hence less commonly seen and used for food packaging. Thankfully, recently we have been seeing a few brands of seaweed from Thailand (the higher price) using this kind of packaging for food and they usually comes with a zipper for the bigger packets.

A good way to reuse these very useful and powerful moisture blocking packaging bags is to wash them and keep a few of them handy in your drawer.

Desiccants

If you are into photography or have paid notice to the way your new bags or shoes are being packed, then the term silica gel will not be unfamiliar to you. They are usually packed in very small paper sealed bags and can be found inside the box with the writing "Do Not Eat" on the exterior of the these sealed bag.

Silica gel is used to absorb moisture and is great even for equipment like camera lenses as mould will grow on them, causing huge financial losses to photography enthusiasts, when used properly. The ones that you usually see comes in blue colour and will turn pink when it has absorbed moisture to its full capacity.

These are great for keeping your food crispy and crunchy and most food manufacturers use them for the same purposes too! However, do take note that these blue silica gels are not supposed to touch your food as they contain a chemical called cobalt chloride that helps to effect the change in colour to know when to change your gels.

You can use the first method of putting your food packaging into an airtight container and proceed to place the gels into the container instead of being in the packaging bag your food comes in.

If you really have to touch the food, use oranges silica gel for your food as these are food grade silica gels suitable for food. These orange gels will turn from orange to green when they have absorbed moisture to their full capacity.

Also consider using a small plastic zip-lock bag to hold your silica gels then use a fine needle to poke pin holes into the bag so that moisture can still go through without your food having direct contact with the gels.

And remember NEVER to use those silica gel packets that comes with your shoes, bags, etc. as these are industrial grade gels (means not to be used with food) and have most probably been at their maximum absorption capacity by the time they reached you. There is a reason why they are almost always in white; the manufacturers doesn't want you to know that these are used up already way before it reached your hands.

There are actually different type of desiccants, e.g. molecular sieve, clay, in the market serving similar purposes for different products but silica gel will most probably be your best bet since the rest are actually not so recommended for food.

For those budding entrepreneurs looking to start a food business and looking into packaging for a bigger production, a talk with a damage prevention specialist may be more recommended since different factors have to be considered on what to be used or done.