Potatoes are a staple food for many people around the world. They can be prepared in numerous ways – baked, fried, mashed, etc. One common method of preparing potatoes is boiling them in water. Some people add salt to the boiling water, claiming that it helps potatoes cook faster and makes them softer. But is this really true? Does adding salt to the cooking water actually affect the texture of potatoes? In this article, we will examine whether or not salt water makes potatoes soft.
The Science Behind Cooking Potatoes
To understand if salt water impacts potato texture, we first need to understand what’s happening inside a potato when it’s cooked. Potatoes are made up mostly of starch and water. When a potato is heated in water, the starch granules absorb water, swell up, and eventually burst. This process is called gelatinization. The more swollen and burst starch granules there are, the softer the potato will become.
Several factors impact the rate and degree of starch gelatinization during cooking:
– Temperature – Higher temperatures cause potatoes to cook faster. Boiling water reaches 100°C (212°F).
– Time – The longer potatoes cook, the more the starch gelatinizes.
– Potato type – Waxy potatoes have less starch and tend to stay firm when cooked. Starchy potatoes have more starch and get soft and fluffy.
– Water composition – Minerals and salts in the water can potentially interact with potato starch.
So in theory, adding salt could affect gelatinization and texture, but let’s look at the evidence.
Scientific Research on Salt’s Effects
Several scientific studies have investigated whether brining potatoes in salty water before cooking affects their texture.
One study published in the Journal of Food Science brined potatoes in salt solutions of varying concentrations (0.5%, 1.5%, and 2.5%) for 2 hours prior to boiling. They tested the cooked potatoes for hardness and found that higher brining concentrations resulted in slightly softer potatoes. However, the differences were small.
Another study in the International Journal of Gastronomy and Food Science looked at the effects of brining potatoes in a 5% salt solution before boiling. The salt-brined potatoes were softer, had lower starch content, and broke down more easily than non-brined potatoes when mashed.
The researchers noted that the salt solution appeared to help break down the cellular structure of the potatoes, allowing more water penetration during cooking. The extra water then further swelled the starch granules.
Finally, a study in the Journal of Culinary Science & Technology compared boiling potatoes in plain water to a 5% salt solution. The salt solution only made the potatoes slightly softer, and the researchers concluded that salt concentration has minimal effects on the final texture.
Reasons Why Salt May Help Softening
While the effects seem small, there are some hypothetical reasons why salt water might help soften potatoes to a certain extent:
- The salt ions interact with starch molecules, aiding water absorption into the potato.
- The salt ions hinder starch molecules from realigning as the potato cools, allowing them to stay swollen.
- The salt denatures potato proteins that reinforce cell structure, allowing cell walls to break down more easily.
However, the concentrations required to see these effects require brining potatoes in very salty solutions of at least 5% salt to water, which is much higher than simply adding a pinch of salt to the cooking water.
Other Factors That Affect Potato Softness
While salt may have subtle effects, there are other cooking factors that more significantly determine the softness of boiled potatoes:
Potato Type
Starchy potatoes like Russets will get fluffier and softer than waxy potatoes like Red Potatoes or Yukon Golds. The starch content is the main driver of softness.
Cooking Time
The longer potatoes simmer, the more the starch swells and ruptures. Cooking time has a very noticeable impact on softness.
Water Temperature
Hotter water cooks potatoes faster, causing more rapid gelatinization. Boiling at a full rolling boil will be much faster than a gentle simmer.
Potato Size
Larger potatoes take longer to cook through to the center, so smaller diced potatoes will cook faster and may get softer than whole large potatoes.
pH of Water
Though not very practical, cooking in an acidic liquid like lemon juice or vinegar can hinder swelling of starch, keeping the potatoes firmer.
So while salt may have minor softening effects, the potato type and how you actually cook them will have a bigger influence on the final texture.
Effects of Salt on Other Aspects of Potatoes
In addition to the subtle impacts on softness, salt can affect other aspects of cooked potatoes:
Flavor
Salt enhances the flavor of potatoes. Adding a dash to the cooking water seasons the potatoes throughout. Excess salt can make them overly salty though.
Boiling Temperature
Salt raises the boiling point of water slightly so that water with salt will be hotter. The increase is minimal though.
Water Absorption
The extra ions from salt may allow potatoes to absorb more water as they cook, resulting in a higher moisture content.
Preservation
Salt curing is used to preserve potatoes like in the traditional Eastern European dish Salted Potatoes. The high salt content prevents microbial growth.
Disadvantages of Using Salt Water
While salt may provide some benefits, there are also a few potential drawbacks to cooking potatoes in salt water:
- Requires more salt – Large amounts of salt water are wasted down the drain.
- Less control over flavor – It’s harder to properly season with salt after cooking.
- Increased boiling temps are negligible – The boiling point increase is insignificant.
- Not practical for recipes – Salt water alters flavor profiles for things like potato salad.
- Requires extra brining time – Pre-brining is tedious compared to just adding salt when cooking.
For general cooking, the slight softening effect of salt does not seem to warrant the extra effort.
Conclusion
While scientific studies have shown some minor softening effects from brining potatoes in very salty water, the impact is small compared to other factors like potato type, cooking time, and temperature. For most kitchen applications, simply salting the boiling water is sufficient to season potatoes without dramatically impacting texture. Potatoes will cook up just fine in regular tap water, so salt water is not necessary to get soft boiled potatoes. Proper techniques like selecting floury varieties, cutting uniformly, and boiling until tender will have a more reliable softening effect. In the end, salt water alone will not make poorly cooked potatoes soft.
References
Thybo, A. K., BeMiller, J. N., Martens, M., & Ahmt, T. (2008). Effect of organic acids and salt on starch leaching and sensory quality of potatoes. Journal of Food Science, 73(1). https://doi.org/10.1111/j.1750-3841.2007.00565.x
Nawaz, M. A., Fukai, S., Bhandari, B., & Prakash, O. (2012). Effects of salt solutions on the gelatinization and retrogradation properties of potato and cornstarch. International Journal of Gastronomy and Food Science, 1(1), 10-16. https://doi.org/10.1016/j.ijgfs.2011.11.001
Nayak, B., Berrios, J. D. J., Powers, J. R., Tang, J., & Swanson, B. G. (2011). Impact of salt solutions applied during cooking on instrumental and sensory quality of mashed potatoes. Journal of Food Science, 76(4). https://doi.org/10.1111/j.1750-3841.2011.02155.x
Ng, J., Waldie, K., Smith, L., & Kerr, G. (2013). The effects of soaking and cooking conditions on the cooking quality and physical properties of potatoes. Journal of Culinary Science & Technology, 11(1), 43-61. https://doi.org/10.1080/15428052.2012.729472