The surface chemistry of draining pasta

[Ivan Viehoff]

I once saw Heston Blumenthal, one of the chefs reputed for his "molecular gastronomy" approach, claim in one of his television shows that it made a difference to the pasta whether you lifted it out of the pan with a "spaghetti claw", or tipped the panful water and all into a colander to drain. He claimed that if you lifted the spaghetti out of the water some starchy component in the water tended to readhere to the surface of the pasta due to surface effects, so it was better to drain it in a colander. I have been unable to track down a reference for this, though if you look for his recipes on the web they do instruct draining in a colander, if they specify any draining method.

I can understand that if you did have a layer of, say, soot lying on the surface of the water, a surface effect would apply and lifting the pasta out of the water would make the soot stick to the pasta to a greater extent that if you tipped it into a colander to drain, where probably a greater part of the soot would remain on the interior of the pan.

But what can be in, or on the surface of, pasta-cooking water that would behave like soot here? And why would you want to avoid it sticking to the surface of the pasta?

[Ara Pacis]

starch

[Ivan Viehoff]

starch

But isn't that in solution? Why would a surface effect apply?

[kzb]

I'm pretty skeptical there is any detectable difference. I wonder if Hestor is one who adds oil to cooking pasta?

If so, you have the potential for a difference caused by the two methods. Lifting the pasta through the surface oil layer may cause it to become oil-coated.

If you pour it through a colander, the oil will go through before the pasta and water hits it.

My personal preference would be for the pasta to be lightly oil coated but maybe that is just plain wrong in Michelin-star world

[profloater]

It is said a little oil added to the water improves the surface stickiness and this would float and would indeed adhere to the pasta surface (or at least some of it) if the pasta is carefully extracted from under the water, through the oil layer and drained of water. This would be less effective if the whole pan is tipped out. The degree to which oil would stick to the pasta surface would depend on several factors, other surfactants in the water, the surface texture, the shape, the viscosity and so on. I do not eat much pasta at home now but if I do I always add a good spoonful of oil to the water in the fond belief it makes a difference, I use placebo oil of course.

[Ivan Viehoff]

Heston uses no oil when boiling pasta. But he does put a lot of salt in the water. Personally, I use neither, though I used to use oil in the past.

[NEOWatcher]

He claimed that if you lifted the spaghetti out of the water some starchy component in the water tended to readhere to the surface of the pasta due to surface effects, so it was better to drain it in a colander.

I guess it depends on the method of going into a colander.
The starch tends to float. (I think... there's a lot of flotsam that's at the top of the pot)
If you lift the pasta out, then you pull it through that flotsam.
If you pour the pasta out, then the top layer of flotsam has a chance to drain off without contacting the pasta.

I would think the best thing to do is pour off the top of the water then drain the pasta.

[Ara Pacis]

IIRC, the oil is to keep foaming down so that the pot doesn't boil over.

[Squink]

Pasta is made with flour, which contains protein as well as carbohydrates. Proteins often foam and produce surface monolayers on liquids (Langmuir–Blodgett films). Sea foam is one example of such a proteinaceous foam. Many pastas also contain oils which can form monolayers at the surface of liquids. Any of these monolayers will coat a pasta to varying degrees depending on how the noodles are removed from the liquid.

[danscope]

The starch is suspended in the cooking water, which should have salt (changes/elevates the temperature of the boil). Save some starchy cooking water
for the sauce (Lydia's good idea). The gravy sticks to the pasta better( when you do not rinse the pasta ). Now, sometimes, I draw out the spagheti
from the water and drop it into a large no-stick pan in which i have sauteed some crushed garlic, seasoned, and with olive oil and butter (some). Toss quickly,
add gravy, toss, add grated cheese (parmesan regiano or pecorino or both) and fresh cracked pepper.I put the hot cooking water into the serving bowl, and thus pre-heat the bowl, serving the dish hot, and it will stay warmer. If you do this, you can cook the spagheti a little closer to ' aldenti' because you are cooking a little longer in the pan. And... if a few meatballs or a little sweet sausage falls into the bowl, you might as well just keep going and serve it.
Bon appetit,
Dan