Potatoes behave differently from other vegetables during cooking because of the presence of starch in them. Unlike tomatoes and onions, they don’t release water during cooking. So, do potatoes absorb water?
Yes, potatoes absorb water while cooking because they’re porous vegetables and contain starch. The starch molecules inside potatoes break down when exposed to heat during cooking and start soaking up moisture. They also absorb water if you leave them to cool down in the cooking water for too long.
Let’s look at this in closer detail.
Why Do Potatoes Absorb Water?
Potatoes absorb water because they’re porous.
This means that their cell membranes allow water to enter the cells.
So, when you place potatoes in a liquid solution, they absorb moisture and expand in size.
If you expose potatoes to water for too long, they lose their structure and flavor and end up becoming soggy and watery.
Potatoes not only absorb water when exposed to a liquid medium but also during cooking.
In this regard, they’re different from vegetables like tomatoes and onions, which release water and shrink during cooking.
Cooking potatoes cause their cell walls to break down.
This releases the moisture in their cells and makes them soft.
Softening during cooking is a common phenomenon for most vegetables.
However, potatoes don’t lose moisture during cooking because they absorb moisture from the liquid in which they cook as they contain starch.
Raw potatoes have a lot of starch molecules.
When starch is exposed to heat, the molecules react by absorbing liquid and swelling up.
This process is called gelatinization. It makes the starch thicken.
When you cook potatoes, the starch molecules absorb moisture and swell up.
This changes its texture and makes it soft. It also increases in size.
This is why you shouldn’t leave potatoes in the cooking water for too long.
It will continuously absorb water from the surroundings.
As water seeps into the potato, its texture changes. It becomes soggy and unappealing.
Hence, it’s essential to remove potatoes from the water soon after cooking instead of waiting until they cool down completely.
Do Boiled Potatoes Absorb Water?
To boil potatoes for various recipes, you either place them directly in water or peel them and put them in water for cooking.
In both cases, it’s advisable to separate the potatoes from their cooking water as soon as they’re cooked.
You should take them out when they’re just tender and not falling apart.
Drain the potatoes and keep them away from moisture once they’re cooked to prevent them from absorbing water and becoming soggy.
Leaving the potatoes in the water for more time than is absolutely necessary will make them absorb more water.
They will turn mushy and not taste good.
Do Potatoes Absorb Saltwater?
It’s a common practice to salt the water used for cooking potatoes. This serves two purposes.
Firstly, salting the water seasons the potato during cooking.
The potato absorbs salt during the cooking process and tastes much better than when you season it after cooking.
The second benefit of cooking potatoes in saltwater is that it allows them to boil at a higher temperature.
Salt helps the starch molecules in potatoes to cook thoroughly.
It will help the potatoes achieve a creamier texture.
Can Potatoes Reduce The Saltiness Of Over-Seasoned Dishes?
Many cooks add potatoes to over-seasoned dishes to reduce the salt level.
It has to do with the potato’s ability to absorb liquid.
In this case, the liquid is salty.
The potatoes help by absorbing the salty water, thereby adjusting the salt level of the dish.
Interestingly, potatoes don’t technically remove salt from the dish but remove the salty liquid as a whole.
Thus, by reducing the amount of salty liquid, they make the dish more palatable.
What Does Soaking Potatoes In Water Do?
If you peel and cut a raw potato and leave it outside, it will oxidize and turn brown in mere minutes.
Such potatoes look very unappealing.
Peeling and soaking the potatoes in water immediately will prevent them from taking on this unattractive brown color.
You can prepare potatoes ahead of time and store them in the refrigerator for up to 24 hours.
When it’s time for cooking, simply rinse the potatoes in cold water and cook them as intended.
Many recipes, including French fries, start by soaking potatoes in water.
Here, the purpose of soaking potatoes is to remove excess starch.
Starch makes potatoes sticky and prevents them from crisping up during cooking.
Excess starch makes them gummy and sticky instead.
Soaking potatoes in cold water helps to get rid of excess starch.
You shouldn’t use hot water for this purpose because exposure to heat will activate the starch molecules in the potato. This can make them sticky.
Another factor to remember is that you shouldn’t soak potatoes in water for too long.
Being porous vegetables, extended exposure to water will make them swell up.
It will alter the original texture and reduce the appeal of the dish.
When cooking potatoes, start them in cold water.
It will allow the vegetables to slowly reach the cooking temperature and improve their texture and flavor.
Why Do You Rinse Potatoes Before Boiling?
After soaking potatoes in cold water to remove excess starch, it’s a common practice to rinse them before cooking.
Rinsing potatoes in cold water washes away the excess starch that was released during soaking.
This improves the texture of the potatoes and makes them light and fluffy.
You can also rinse the potatoes quickly after boiling to remove any remaining starch from them.
It’s fine to use hot water to rinse the potatoes at this stage.
Do Potatoes Absorb Sugar Water?
Potatoes contain sugar and have a high glycemic index.
The movement of water in and out of a potato depends on whether the potato contains more or less sugar than the liquid it’s placed in.
This process is called osmosis.
When you place potatoes in a sugar solution, osmosis will occur in or out of the potato, based on the concentration of sugar in the solution.
If the concentration of sugar inside and outside the potato is comparable, there will be no water movement.
However, if the surrounding solution has less sugar, water will pass through the cell membrane into the potato.
This will make it swell and increase in mass.
If the solution is highly concentrated, the reverse action occurs, and water moves from the potato into the surrounding solution.
Do Sweet Potatoes Absorb Water?
Although sweet potatoes have the term “potato” in their name, they aren’t related to regular potatoes.
Nevertheless, sweet potatoes are starchy vegetables, and their reaction to water resembles that of regular potatoes.
Sweet potatoes absorb water and become soft when cooked or placed in a liquid.
Similar reactions also occur when you cook them in water.
When you cook sweet potatoes in water, the starch molecules absorb water and swell up.
It makes the vegetable soft and tender.
Leaving them in water for too long can adversely affect their texture because the vegetables break down and become mushy.