The secret is that restaurants which make traditional cacio e pepe are using pasta water to emulsify the sauce.
But it's not the same pasta water you're using at home!
Only a tiny amount of starch is coming off of the 500g of pasta you just cooked in the proper ratio in 5000g of water (with 50g of salt). They've been cooking with their pasta water all day or all week; It's completely full of starch that came off the other pasta.
Dump a bunch of cornstarch or flour in there to get above 1% concentration (or more efficiently, into a tiny portion in a bowl) to replicate the emulsifying effect, or just use a different emulsifier.
I’ve been doing it with little water since forever. It would take ages to boil a lot of water before I had an induction stove, so I tried with little and it worked the same.
100g of dry pasta turn into about 230g of al dente pasta. thus 200g of water per 100g of pasta is plenty. bring to boil. pasta in.
lid on(!), heat way down, to a simmer, very very slight boil. stir after 40% of the cooking time. taste and chewiness testt
after the advertised overall cooking time. if the pasta form is very fluffy then have a little preheated water handy should your pasta unexpectedly need more water. hint: it won't. but an unusual pasta form may rarely ask for more water.
drain and catch the starchy water if you think you need it. (I personally don't like the taste and prefer adding starch to the sauce if needed, but ymmv here). rinse pasta briefly to stop the cooking and ensure all dente chew.
energy saving compared to "recommended standard method": 80%. eighty percent less energy. (200ml instead of 1000ml). more actually, because the lid is on.
Don't add powdered starch to hot water. It will clump. Add it to a small amount of cold water and then add that to the hot pasta water. (And the starch you want is amylopectin. Waxy potato starch will work better than corn starch [1].)
First, temperature dynamics and being able to reliably determine doneness by time. Boiling water is nature's thermal measuring stick, and if your water is dropping to 150 it's a Problem. This is especially the case if you like to let the water 'coast' heat-off so that your pasta doesn't burn to the bottom of the pan during an unattended rolling boil.
Second, clumping. You want the ability to freely stir and get water between pieces of pasta, or if the heat is on for the boiling bubbles to stir, in order to avoid the pasta sticking together.
Third, use 80% less water and you only get a 5x higher concentration of starch. I don't have measurements in front of me but I suspect this simply isn't starchy enough to take a tiny portion of that water and use it as an effective emulsifier. The article pins 1% starch as a threshold of effect, and I doubt I'm losing 0.2% of pasta weight when cooking to al dente.
Note: This is all for dried durum wheat-flour pasta, the generic industrial 'macaroni' of American agribusiness. Egg pasta is a very different product, with different cooking characteristics, that happens to share the name. Durum semolina pasta, whole-wheat pasta, gluten-free "pasta", rice pasta... no guarantees that this is applicable.
Correction: To attain 1% of 5kg of water, I need 50g of starch. In 500g of pasta, there's no way in hell I'm losing fully 10% of the weight of the pasta. If I cut the water to pasta ratio by 80%, I would still need to lose 2% of the weight of the pasta, and I don't think that's happening.
- You can't rely on box cooking times even as a starting point. Your pasta will take significantly longer to cook, since it will bring down the temperature of the water when you put it in, since there's so little water
1. The starch comes from the pasta, not the water. Decreasing the water increases the concentration of the starch in said water. That’s why every good recipe for cacio e Pepe I’ve seen recommends using as little water as possible
2. This has been thoroughly debunked. Kenji did a full write up of this but suffice to say that starches absorb water starting at 180 degrees. As long as you have the water above that temp it will cook in the same amount of time.
In my experience box cooking times are never quite right, and irrelevant if you're going to be finishing your pasta in the sauce anyway.
Unless you're extremely familiar with the exact brand of pasta, temperature of your stovetop, etc., you should be tasting your pasta toward the end of cooking to decide when to stop cooking it.
> - It's still not going to be enough starch
I'm inclined to disagree, but only have anecdata on this, so I can't really get into an extended debate over it. So I guess now I get to look forward to experimenting with starch additions the next few times I cook pasta.
I don't get clumping. I use an adequate quality pasta (De Cecco mostly), stir it when I put it in the water, and a few times after that, cooking to al dente. If I'm making a Caccio e Pepe or Carbonara I cook the spaghetti or (my preference) Buccatini I'm aiming for the minimum amount of liquid left, ideally just enough to put in the sauce. I use a frying pan so I can lay the noods out flat to minimise the water.
As I said I don't get clumping, it is absolutely possible to cook noods in minimal water without clumping because I do it so try switching some thing up if it's happening to you.
How do you stir long pasta in minimal water before it has softened?
While small pasta shapes are relatively easy to stir such that they break contact with anything nearby right from the beginning, long pasta tends to move together when stirring until they’ve softened - at which point they’ve already started sticking together.
You can try to stir it so that the pasta isn’t all running parallel before it softens, but then you get ends start sticking out of the water until it softens more, leading to uneven cooking.
For long pastas, I’ve found using more water and just adding a little flour while cooking to be a lot easier.
I use kitchen tongs to pick up and jostle the noods as another commentator mentions. It starts out parallel as you say. Flour would add a flavour I didn't want and I don't have an issue with uneven cooking or clumping so I don't need to.
shrug then go with De Cecco, it's still better than Barilla. But if you find a Molisana or especially a Garofalo, do grab a pack and taste the difference.
I'll pick up a pack if I see it. The top quality the supermarket we go to has is Rummo, it's the next step up from De Cecco (in the supermarket at least) and I buy it sometimes, but to me there's not a hell of a lot of difference between the two for the price difference.
Sometimes I forget to stir and have to reboil the pasta. Long noodles like spaghetti will stick like crazy and have inconsistent cooking. If I need to cook quickly I use less water. Otherwise more water is hands off.
Also, if you’re using home-made, artisanal, or just some better rough-surface pasta, it will release a lot more starch than the standard smooth-surface sort.
In a restaurant that makes pasta as a focus you don't "boil it quite often", you boil it constantly. Many gallons of boiling water takes forever to come up to temperature, and once it's there the pot can be thermally insulated to keep it there above 200F with minimal additional heating. Customer orders, you dump it in, customer is served in 5-15 minutes.
You keep it at a slow boil, and properly salted, all day long. If you're using it more than one day, you'd probably want to keep it hot overnight, like "perpetual stews", but I can't attest to how common this is, especially in restaurants that aren't constantly plating pasta.
You can manage it as a batch process, throwing the water out when it gets too starchy, but doing this unaided leaves you unable to use the water as emulsifier at the start of the cycle. You could also do it as a perpetual process by pouring some off the top and refreshing with clean water.
Gross part is that you are boiling same liquid in open space where people are working and making a mess. Also you are going to accumulate residue ar the bottom.
Unlike meat or vegetables this can't be washed.
Do you find it gross when there's a big stockpot simmering stock for 12 hours without a lid in order to reduce?
And what's to wash? You don't wash food after cooking, and pasta is like bread -- it certainly doesn't need washing beforehand either. It's just flour and some other ingredients.
It's not like vegetables where you need to wash off dirt, pesticides, etc. Or meat where you wash off bacteria. Those aren't issues with pasta.
I do not. I didn't make myself clear in first comment. Sorry for that. I was talking about using same water for a whole week. I felt that it is not optional. The residue building at the bottom, open space of messy kitchen with lid open and constant reheating because it cools overnight is what seems little bit off for me.
Oh, I see - yeah I've never heard of a restaurant using the pasta water across days. I don't think that's a thing. In fact it's a whole thing about how the pasta gets better throughout the day, because you start with fresh water each day. And remember that water is constantly being added to the pot as it gets soaked up by the pasta.
Just from a food safety perspective I'm not sure it's legal to reuse across days, given that it's going to take all night to cool, only just in time to be reheated again.
Ahhhhhh, I also misunderstood your comment. Yeah, I hear you. Maybe you can keep the starch water in airtight container...not sure. I don't keep starch water for the next time I'll cook pasta. I just use the currently made starch water to create a sauce. Highly recommended! But, as mentioned in the research, wait for the water to cool down a bit. Or make a risottata in a pan. <- also highly recommended if you have a pan big enough.
I guess you don't wash flour, but it does need to be disinfected (eg by cooking it) - it's a little unsafe to eat raw, which is the problem with raw cookie dough.
If there was a way to get rid of the insect eggs people would presumably want to do it too, but iirc they're just too small to filter out.
But it's not the same pasta water you're using at home!
Only a tiny amount of starch is coming off of the 500g of pasta you just cooked in the proper ratio in 5000g of water (with 50g of salt). They've been cooking with their pasta water all day or all week; It's completely full of starch that came off the other pasta.
Dump a bunch of cornstarch or flour in there to get above 1% concentration (or more efficiently, into a tiny portion in a bowl) to replicate the emulsifying effect, or just use a different emulsifier.