Thursday, December 07, 2006

Heston's roast potatoes

Sorry: him again. There were three components to his perfect roast chicken meal on Tuesday night: the chicken, the roast potatoes, and the carrots. I wrote about the chicken yesterday, and I shall come to the carrots some other time. There are a couple of features of his roast potatoes I want to mention.

Blumenthal boiled his potatoes -- Maris Pipers -- until they were crumbly at the edges. As he said, you have to get the timing right: a minute later, and they would have turned into mash. But, as I have written, I parboil maincrop potatoes for just a few minutes, to get rid of some of the surface starch. The edges will crumble a little if you stir them in a hot, dry pan, and be crunchy once roasted.

On the other hand, Heston Blumenthal is a Michelin three-starred chef, and I am someone whose daughters accuse of being unable to cook frozen peas properly.

He boiled two batches of potatoes: one in salted and the other in unsalted water. The former batch was crunchier when roasted, he said. He did not explain why -- although he may do in his book. Turning to his guru -- and mine -- Harold McGee, I learn that the reason may be that salt speeds the softening of cells. The potatoes from the salted water were probably crumblier.

He roasted his potatoes in olive oil. I do too, sometimes; but more often I use sunflower oil -- frowned upon in some quarters.


Anonymous said...

The extra crunch in the potatoes boiled in salty water could be the result of straightforward increased extrusion of water from potatoes by the saline/hypertonic water. The dehydration of the potatoes increases the crunch.

Nicholas Clee said...

Yes, that sounds like a plausible theory.

I may change my mind in the winter, when potatoes are more floury, but at the moment I prefer not to parboil potatoes first. What you lose in crunchiness, you gain in sweet/earthy flavour.