I freaking knew it!
Spaghetti and other pasta recipes have repeatedly asked us to “boil with salt” – a rule that has always baffled me. Once, early on in my cooking life, I decided to be a good boy and add the salt as requested only to find that it didn’t make a lick of difference to the end result. I haven’t looked back since.
In an interview with website, President Online, Tokyo Kasei University Graduate School of Home Economics, Keiko Nagao, puts this myth of boiling with salt to rest once and for all, thus saving us from a needless cooking step.
The question has been prominent in Japan where various types of long noodles are used alongside spaghetti. Prof. Nagao points out that we are generally told to boil spaghetti at a pasta-water-salt ratio of around 1-10-0.5, but noodles such as udon never recommend adding salt when boiling.
One reason for this is the flour used in making the noodles. Udon uses all-purpose flour which has very good elasticity, but is viscous and firmed slightly when salt is added. On the other hand, spaghetti is made with hard flour which has about 50 percent more gluten than udon, giving it an already firm form which can be more difficult to work with. As such, the addition of salt to udon can be a hindrance during production.
This might be the reason why adding salt to spaghetti while boiling can give its texture a similar boost, in the same way that kneading udon dough improves the texture. Nevertheless, Prof. Nagao has not seen that effect.
“There have been tests conducted by expert cooking researchers to compare spaghetti boiled with and without salt, but no changes were observed in the texture of the noodles. To put it another way, the amount of salt used was not seen to change its feeling inside the mouth. Myself, I don’t even put a gram of salt in at home or in classes. We have quantified the elasticity of the noodles boiled both ways by machine and the results were the same.”
Now that it’s established that salt doesn’t affect the texture, how about the flavor? Prof. Nagao mentions that it’s widely believed that salt reacts with the glucose, amino acids, and minerals of spaghetti to bring out the flavor. However, to do so effectively you would need to add it in large amounts.
Restaurants can be seen boiling pasta in lots of salt because they want to give customers a strong and memorable flavor. Health is not a major concern for them since they usually don’t feed the same people every day. Doing the same thing in your own kitchen wouldn’t be advised for the sake of your blood pressure. With salt off the table, Prof. Nagao talks about how controlling pasta firmness is really just a matter of how you boil it.
“First, the time, then the temperature and amount of water are most important. If the temperature of the water is too low, the starch on the surface of the noodle melts off and the water becomes oozy and sticky. Also, if the amount of water is too low then the temperature of the water drops the instant the pasta is added. As a result the same thing would happen. Not only that, the pasta would block the flow of the boiling water and cause it to cook unevenly. On the other hand, if the boiling is too strong or there’s too much water, the starch on the noodles instantly becomes gelatinous, making the pasta taste the same as if you used too little water.”
So, next time you make some pasta, you’ll be better off throwing the salt over your shoulder for luck. Instead, it’ll take some trial and error and the help of a thermometer and timer to achieve that perfect batch of spaghetti.