I have all the tools I could possibly need for my gas grill — a cast iron plancha, remote thermometer, metal box for wood chips — and I love them all. There's one thing I never really loved, though: the stainless steel vegetable basket. It definitely keeps small foods from falling through the grates, but it's too small itself to effectively grill these items without crowding.
However, a new breed of copper grill mats aims to solve this problem. They're super-thin, flexible sheets of heat-resistant material woven with copper threads and covered in a nonstick coating. They're big enough to allow foods to really spread out and they keep oils and marinades from dripping through, so there are no flare-ups. Plus, since the copper conducts heat, you get those all-important grill marks and browning.
Sounds great, but do they really work? I recently tried one out and the short answer is: sort of.
There are three main brands on the market in the U.S. and they're pretty much identical, right down to the cheesy "As Seen on TV" packaging: Gotham Steel, Copper Chef, and Yoshi. The latter is the easiest one to find (it's sold in a box of two mats for $9.99 at Target, Walmart, and Bed, Bath & Beyond), so that's the one I tried.
Where to Find These Copper Grill Mats
Like the other brands, the Yoshi mats are supposed to be used with medium to medium-low heat, and not above 500°F. (These are the same guidelines for a nonstick pan, because high heat can damage the nonstick coating.) They also aren't meant to be used over open flames, which means you need a gas grill with covered burners or, if you're using charcoal, wait until the briquettes burn way down.
For my experiment, I preheated my gas grill to medium (375 to 400°F), added the mats, and let them preheat for a minute too. Then I added a bunch of things that are tricky to grill without slipping through the grates: cauliflower, wild mushrooms, asparagus, scallions, red peppers, and marinated shrimp.
I was very happy to see that the veggies did indeed take on a lovely browning. The red peppers got good and blackened, the scallions got nice grill marks. The mushrooms and cauliflower were evenly golden.
The shrimp, however, never got grill marks and only a little browning. I thought maybe the oily marinade acted as a buffer and kept them from getting seared. Maybe if they had less oil, or a really sugary marinade that's prone to caramelizing, or maybe if it was a protein that had to sit on the grill longer I might have gotten those coveted marks.
To test out those theories I marinated some pork cutlets in a really sweet teriyaki sauce and slapped them on the grill. Again, no grill marks — although after turning them over, the second side of one of the cutlets did have some faint light brown stripes.
I then tried grilling a delicate fillet of dover sole, which I had lightly coated with pesto on one side. The fish was a breeze to handle on the nonstick mat, but there was no browning on either side.
Copper Grill Mats: The Bottom Line
If grill marks on your protein are important, skip the mat. However, it does make grilling fish and veggies super easy. The asparagus, in particular, was fantastic. They were nicely browned, similar to when they're roasted in the oven, but they had a hint of sweet alder smoke from the chips I added to my smoker box. I can't do that in my oven — or at least not as easily.
What do you think? Will you try one of these?