{"id":28850,"date":"2014-01-10T00:12:07","date_gmt":"2014-01-10T08:12:07","guid":{"rendered":"http:\/\/www.todayifoundout.com\/?p=28850"},"modified":"2016-02-11T00:56:11","modified_gmt":"2016-02-11T08:56:11","slug":"causes-pasta-froth","status":"publish","type":"post","link":"http:\/\/www.todayifoundout.com\/index.php\/2014\/01\/causes-pasta-froth\/","title":{"rendered":"What Causes Pasta to Froth"},"content":{"rendered":"

\"cooking-pasta\"<\/a>Today I found out<\/a> why pasta causes boiling water to froth.<\/p>\n

We\u2019ve all done it: you put the pasta on to boil, turn your back for a few minutes to wipe off the counter or read the newest Today I Found Out<\/a> article, and suddenly you hear that foreboding hissing sound of water boiling over. (Perhaps if you simply subscribed to our Daily Knowledge YouTube Channel<\/a> and been listening instead, you’d have avoided this issue.\u00a0 You really have only yourself to blame. ;-))<\/p>\n

So why does it happen? It has everything to do with the composition of pasta. Pasta is made from flour, water, and sometimes egg\u2014that means it\u2019s basically just starch and protein rolled out into different shapes and dried. It\u2019s the starch molecules that are important. Once they\u2019re heated in a moist environment\u2014like your pot of water\u2014the starch will absorb more and more water until it finally bursts. That sends little starch molecules into your water, resulting in white foam.<\/p>\n

It\u2019s the foam layer on top that causes the problems. What has happened is the starch makes the bubbles that were already there more stretchy and pliable, so it takes longer for them to burst. A lot of bubbles on the surface doesn\u2019t allow for proper ventilation of steam, meaning the pot of boiling water becomes superheated if the pot isn\u2019t stirred or the frothy layer skimmed off the top in time. The trapped steam causes the frothy bubbles to expand and pop up, resulting in boiling-hot pasta water all over your stove if you\u2019re not careful.<\/p>\n

How can you stop the water from boiling over? Here are a few tips that should get you through your next pasta meal boil-over free:<\/p>\n

    \n
  1. Don\u2019t leave a lid on the pasta pot. This makes the starch molecules heat up very quickly. Leaving the top off allows steam and heat to escape more easily. Alternatively, for those who like to save energy by using a lid, simply turn the temperature of the burner down so that it\u2019s just high enough to keep the water boiling.<\/li>\n
  2. Leave a wooden spoon lying across the pot. This doesn’t work that well for massive foam swells, but for minor ones helps. Here\u2019s how: when the foam bubbles up it will eventually meet the spoon. The foam is thermodynamically unstable, which means when the bubbles reach the spoon they will burst, breaking the layer of foam and sending the bubbles collapsing down again.<\/li>\n
  3. Use a bigger pot. With higher walls to climb, the layer of foam likely won\u2019t be able to bubble over the edges.<\/li>\n<\/ol>\n

    There are also a few commonly touted tips that won\u2019t actually keep your pasta from boiling over, or that shouldn\u2019t be used to keep the pasta from boiling over.<\/p>\n

      \n
    1. Add salt to the water. By all means, add salt for flavour (see: Why Salt Enhances Flavor<\/a>)\u2014that\u2019s the way many Italians claim it should be done. Salt isn\u2019t added to pasta dough, but pasta will absorb it while boiling, giving it a little something extra. However, salt won\u2019t make the water stop frothing; it also doesn\u2019t make the water boil faster (unless you add an unpalatable amount of it!)<\/li>\n
    2. Add oil to the water. Okay, so this one does work by adding a different sort of surface tension to the water, meaning the bubbles will burst faster and you won\u2019t encounter the problem of superheating. However, adding oil to the water has the negative effect of making all of your sauce slide off the pasta when it\u2019s ready, so most cooks don\u2019t recommend it.<\/li>\n<\/ol>\n

      If you liked this article, you might also enjoy our new popular podcast, The BrainFood Show (iTunes<\/a>, Spotify<\/a>, Google Play Music<\/a>, Feed<\/a>), as well as:<\/p>\n