Using Grill Cover Changes Flavor Of Foods

The best grilled food is, well, grilled. It is cooked directly over the heat and flame of a live fire. Reach for the cover and you are cooking by another method - which means you are likely to end up eating food with a flavor that you never expected.

The flavor of the cover.

That doesn’t mean all grill covers should simply be tossed away. While the advent of the covered kettle grill may not rank with that of the internal combustion engine, it was still a major event. It allowed backyard cooks to smoke-roast large items and to approximate true barbecue.

But the covered grill has been a mixed blessing, tempting its devotees to use it whenever possible, not just when it is appropriate. The result, although not as dire as the polluted skies that arrived with the automobile, is something every cook wants to avoid: food that does not taste as good as it could.

Let’s say that you have some thick, juicy pork chops over the fire, and they’re starting to burn on the outside but are still raw on the inside. Or the fat is dripping onto the coals and causing flare-ups. What do you do? Many people grab the cover, slap it on and finish cooking.

That solves the immediate problem. But when the chops come off the grill, they will have an off flavor that results from relatively short bouts of covered grilling.

The flavor, somewhat difficult to describe, is readily recognizable to anyone who has covered the grill while preparing quick-cooking foods like chicken parts or hamburgers. It is a taste that is slightly ashy and a bit metallic, with a kind of soggy smokiness, and it brings to mind the inside of the grill cover itself.

As with everything in cooking, this is a matter of taste. But after 20 years of grilling experience, we have developed a couple of ground rules for covered grilling.

First, put the cover over the flames only when cooking something like a whole chicken, beef brisket or pork roast. They need to be on the grill for 45 minutes or longer for thorough cooking. That is approximately how long it takes for the smoke flavor created by covered grilling to become more prominent than the cover’s flavor.

Second, in covered grilling it is best not to put the food directly over the coals. Instead, use the indirect heat of a fire built on the opposite side of the grill from the food.

This principle results from both experience and simple culinary logic. Over the years, we have found that when food is positioned directly over the coals and covered, it retains some ashy covered flavor even after cooking well in excess of 45 minutes.

The exact reason for this is not clear, but may result from fat dripping onto the coals. When this occurs, the fat forms benzopyrene, a possible human carcinogen. Just as smoke flavors the food more during enclosed grilling than open grilling, so it seems logical that benzopyrene may also affect the food more when the cover is on than when it can dissipate into the air.

Even apart from health concerns, food flavored with vaporized fat is not nearly so appealing as food imbued with the taste of smoke. So build that fire off to the side.

These guidelines allow the griller to make the best use of the primary virtue of the grill cover, its ability to impart the slightly charred, smoky flavor of live fire to your brisket, pork roast or whole chicken.

But what about thick-cut pork chops, duck breasts or thick fish steaks, those in-between items too large to be cooked directly over the fire but too small to qualify for 45 minutes under the cover?

Fortunately there are techniques for grilling these foods uncovered while still avoiding uneven cooking and excess flare-ups.

The first of these is the sear-and-move technique. The foundation of this method is the two-level fire, which is simply a fire with many coals on one side of the grill and far fewer, or none at all, on the other. With this arrangement, the griller can always move food back and forth from hot to relatively cool spots on the grill, regulating its interior and exterior cooking.

So when a pork chop or duck breast, for example, is nicely seared on the outside but still too raw in the center, it can simply be moved over to the cool side of the grill. Then cooking on the outside basically stops, but the interior will continue to cook by radiant heat until the chop is removed from the grill.

This method is very effective and is the most common technique used by professional grill cooks.

There is a second method, which might be called cooking on the edge.

It is most useful for large dishes like rack of lamb, bone-in chicken parts or whole fish. In this method, the griller cooks the food on the edge between the hot and not-so-hot sections of the fire, shifting back and forth depending on how quickly the food is browning.

The only potential drawback to this method is that it takes plenty of patience and attention. But then, part of the attraction of grilling is the challenge of dealing directly with the unique and unpredictable nature of each fire.

And, besides, practicing your grilling finesse gives you an ideal excuse for spending more of the summer outside hanging around the grill.

The following fields overflowed: BYLINE = John Willoughby and Chris Schlesinger New York Times News Service