A few weeks ago FCI's Dave Arnold posted the first installment
of his thorough analysis of the perfect french fry (one so flavorful & crispy that you would still want to eat it once cold). The second installment analyzes different blanching techniques & reports on their respective outcomes.
Arnold pitches four rules to blanch for the perfect fry:
First Rule: Use salt water to blanch.
Second Rule: Blanch fries for a long time –like 14 minutes and 30 seconds, in boiling water (assuming it takes about 1 min 30 sec for your pot to return to a boil).
Third Rule: Make sure your blanching water is boiling, and don’t let the water temperature get below 80°C.
Fourth Rule: Soak your fries in a 0.4% solution of Pectinex SP-L at 25°C for about an hour before you blanch.
The last rule may venture a little too far into the realm of chemistry for many cooks, but Arnold offers a slew of tests arguing for it's use. Whether you're interested in the chemistry or completely turned off by it, there's a ton of helpful & interesting info in the article. Like mosts posts in Cooking Issues
, it's a must read.