Al dente cooking is a transitional state that lasts for a very short amount of time (one minute longer in boiling water makes pasta too soft, one minute shorter and it's still crunchy). For this reason, authentic Italian pasta packages state a precise cooking time, which is very reliable to make a good al dente pasta.
A cooking time interval (e.g. "7 to 10 minutes") is usually given to accommodate to other countries taste, who may prefer a softer pasta, and therefore its presence could be a good indicator of an Italian look-alike pasta brand. In this case the lower figure indicates the al dente cooking.
Lacking this information, a good cooking time can be figured by cross section size, length and shape of pasta: obviously, thicker and squat formats require more time. Complex shapes, such as farfalle, can be trickier because a thick core could reach the al dente cooking while the thinner edges are already too soft.
As a rule of thumb, cooking times for common pasta formats are:
- Long and very thin (spaghettini, bavette): 6 min
- Long and thin (spaghetti, linguine, bucatini): 8 min
- Short and thick (maccheroni, rigatoni, fusilli): 12 min
- Small and thick (farfalle) : 8 min
- Small and thin (pasta usually boiled straight into broth): 6 min
These cooking times apply only for dry durum-wheat pasta; other types (such as fresh egg pasta) usually have a shorter cooking time.
After straining the boiling water, pasta continues to cook by its own heat; for this reason it has to be eaten as soon as possible. Only for some Italian regional recipes (typically pasta boiled straight into a thick vegetable juice, e.g. pasta with beans, pasta with potatoes) you may want to let it rest for up to 5 minutes after straining to let the juices coagulate.
Also, for recipes where pasta has to undergo a second cooking after boiling (e.g. stir frying in a pan with vegetables, shrimps, mushrooms, etc.) a better result is obtained by boiling pasta just one minute less than the cooking time given on the package.
You might have given the answer in your question. If the device is to be used as a steamer as well, then there has to be enough room at the bottom of the pot for steaming. How much is enough? There are two things to consider:
The bottom section should hold enough liquid that there won't be concerns about boiling the pot dry for anything you might want to steam. Longer steam items might include mussels, lobster, or tamales.
There should be some 'air margin' for foods like tamales or broccoli, so that the boil splatter doesn't render the food soggy.
Based on FuzzyChef's comment, it sounds like there are tools that suit your needs better. Perhaps it's time to put your steamer on Craigslist? :)
Best Answer
Optimal texture is about optimal heat transfer. When a vegetable releases so much water that it simmers in its own juices instead of pan-roasting, you should increase the heat transfer.
To achieve that, you need to 1) use high heat, 2) not overcrowd the pan, and 3) use a pan which is capable of better heating. Cast iron is perfect for these situations, heavy steel pans too. Aluminium is much harder to work with, especially if it's thin. Also don't use a nonstick pan, you'll destroy the coating at the temperatures needed.
This technique can be used on its own, or combined with something else, for example oven drying. But note that a zucchini is over 90% water, so you won't be able to simply get it dry enough to resemble a dough noodle.