The Food Scientist's Guide To Grilling Vegetables

The Food Scientist's Guide To Grilling Vegetables

Spark has a full range of oven-like control and functions that let you do more than ever with a charcoal grill. Our precision control allows for perfectly-cooked food at versatile temperatures and duration - from smoked brisket at 225°F, to reverse seared grilled wagyu steak at 700°F. Sure, we love how prime cuts of beef or fresh seafood turn out, but some of our favorite things to come off a Spark are simple vegetables.

Our Food Scientist, Kyle, is our resident veggie expert. Here are his top tips for grilling vegetables from grilled avocado to grilled cauliflower: 

Shop local. 

The best way to get your hands on in-season produce is to shop local. Here in Boulder, our Farmers Markets are incredible and well stocked with beautiful produce, artisan breads and more. COVID-19 has forced Farmers Markets to get creative - most offer curbside pickup, reservations and even drive-through service. Joining a CSA (Community Supported Agriculture) is another way to stock up on seasonal, local vegetables. To find CSA programs in your area, check out Local Harvest. One of the major perks (aside from supporting local farmers) is that you’ll receive a variety of different items that you may never have added to your cart for at your grocery store. The possibilities - and creative recipes - are endless! 

Fresh is best.

Degradation of nutrients and pigments happen over time as a function of oxidation, photo-oxidation, enzymatic activity, temperature abuse, microbial activity, etc. You can get a head start with produce picked when it’s ripe and grows best seasonally; you get the highest quantities of pigments, nutrients, size, and an improved ratio of saccharides; i.e. complex starches to sugar.

Prep school. 

Prepping vegetables for the grill is super easy - yet one of the most important steps. The way you cut matters - the more surface area, the better (more room for that smoky flavor to absorb into the vegetable). For example, cut zucchini and summer squash in long uniform slices and trim bell peppers lengthwise (and remove the stems and seeds). 

For larger vegetables, like root veggies, cut them down to  roughly ¾” uniform diameters for individual pieces. This will give you nice consistency with your grill session. You can pre-cook them; consider throwing big potatoes and carrots in the oven for a while in aluminum foil to trap the water, but soften the fibrous cell structures (time/temp dependent on size/density). Cook them until soft (but not so soft they fall apart) and use the grill as a way to finish them. Focus on getting those nice grill marks as this will yield more complex flavor compounds.

Sometimes we forget how good simple foods are when cooked over wood and charcoal. Our Briqs are packed with flavor, so the best way to prepare grilled vegetables for the Spark is with a little bit of oil, salt and pepper. 


For smaller vegetables that are difficult to cut and trim, toss ‘em into a grill basket. An added bonus of the basket - you get the blended flavors of all of your vegetables grilling together.

A grill basket is also an easy way to maximize the space on the grates, allowing more room for the other things you’re cooking. You can also use skewers for smaller vegetables - just remember if you’re using wooden skewers, soak them in water to prevent them from catching fire. 

Low and slow.

The cells holding water and flavor compounds in vegetables become more and more damaged the hotter the temperature is,  which releases all the good stuff. We recommend not going above 400F for most produce. Another benefit is caramelization; a lot of produce has some sugar in it. Carrots, for example, benefit from “low and slow” as they have a relatively high sugar content and will caramelize. Plus their fibrous cell structure will swell with moisture when heated making them nice and tender.  Grilling at 230-320F, depending on the produce, is best for caramelization. A coating of oil helps vegetables tolerate a higher temperature and helps to lock in moisture, increasing your odds of getting a great grilled veggie.

Charred grill marks.

Maillard browning is a beautiful reaction - the amino acids and sugars all working together to make food taste and look great. High quantities of these in meat help create high quantities of flavor and aromatic compounds. True for produce? Yes! Just not as much. Depending on the veggies you’re cooking, you’ll get some of the benefits of this non-enzymatic browning reaction. Focus on the flavors that come from the caramelization. Cook them excessively and you get charring - that black crunchy stuff. The real black char may have lost a lot of the flavor compounds that used to be there, leaving you with carbon and some other stuff that's best consumed in small quantities. I’m not your doctor, but I know just a little black char adds a really nice contrast to your experience; crunchy texture, astringency to balance sugar and fat, and an oddly satisfying complexity… not to mention that sense of primal  authenticity that comes with grillin’ and getting those black/brown grill marks.

No more quarantine recipe rut.

At Spark, we are all about culinary creativity and we love the unexpected. We’ve rounded up a few of our favorite grilled vegetables for you to try next time you’re craving something new:

Grilled Avocado
  1. Cut the avocado in half and remove the pit. 
  2. Drizzle with oil and a little bit of fresh squeezed lemon juice.
  3. Place cut size down on the grill for 3-5 minutes.
  4. Finish with salt and pepper. Slice and serve or fill with your favorite salsa or ceviche.

    Loaded Grilled Cauliflower Steaks (because is there anything cauliflower can't be substituted for)?

    Grilled Potatoes

    1. Boil whole potatoes in a mix of water and white vinegar until soft.
    2. Slice in ¼ inch thick slices.
    3. Season with salt and pepper and grill for a few minutes on each side, until those perfect char marks appear.

      Main Squeeze.

      Grilled vegetables not only make great side dishes and appetizers, but there are countless ways to prepare them as main dishes. Think beyond the black bean burger and try these mains next time you fire up your grill:

      1. Stacked Vegetable Sandwich
      2. Grilled Ratatouille
      3. Grilled Summer Herb Garden Pizza 


      Made too much?

      Grilled vegetable leftovers are super versatile. We love grilled onions, grilled bell peppers, or grilled carrots in a frittata or quiche for breakfast. Bonus points for grilling your frittata in a cast iron skillet the next morning.