For the caramel: In a medium nonreactive saucepan and without stirring, bring sugar, water, corn syrup, and lemon juice to simmer over medium-high heat, wiping sides of pan with wet cloth to remove any sugar crystals that might cause syrup to turn grainy. Continue to cook until syrup turns from clear to golden, swirling pan gently to ensure even browning, about 8 minutes. TIP: USE A LIGHT COLORED PAN SO YOU CAN OBSERVE THE COLOR CHANGE. Continue to cook, swirling pan gently and constantly, until large, slow bubbles on mixture’s surface turn honey-caramel in color, 4 to 5 minutes longer. Remove pan immediately from heat and, working quickly but carefully [the caramel will burn if it touches your skin], pour a portion of the caramel into each of 8 un-greased 5 or 6-ounce (140-170 ml) ovenproof ramekins. Allow caramel to cool and harden, about 15 minutes. [Can be covered with plastic wrap and refrigerated for up to 2 days; return to room temperature before adding custard].