grapes substitute
for marinade.

Pit and blend cherries with oil, salt, and thyme; cherry juice tenderizes similarly to grape (pH 3.8 matches exactly) so marinating times carry over 1:1. Expect a deeper red stain on white meat than grape leaves behind. Strain thoroughly before grilling to prevent anthocyanin char on the grate.

Blend blueberries with olive oil, balsamic, and rosemary for pork loin. Their tannins add depth grapes lack, but the sugar caramelizes deeply at 180C, so pat the meat dry before searing or it will scorch. Use a spoon-strain rather than fine mesh to keep some skin bits for color.

Hull and puree strawberries with oil, lime, and black pepper; the enzyme activity here is milder than pineapple but stronger than grape, so cap marinating chicken at three hours and pork at five. Strain thoroughly as pulp burns black in direct flame within 20 seconds.

Puree plums (pitted, skin on) with garlic and oil for a marinade with deeper color than grape. Plum juice has about 20 percent more tartaric plus malic acid, so marinate 30 percent less time to avoid protein mushing. Strain before grilling to prevent skin char on the grate.

Blend watermelon with oil, lime, and salt for a mild marinade. Low sugar (6 percent vs grape 16 percent) means gentler browning during a sear, so crank direct heat to 230C. Strain aggressively as watermelon pulp breaks down into water within an hour at room temperature.