Continue stirring, and add reserved chocolate in three stages. Remove bowl, and bring down temperature by stirring constantly until mixture is smooth and drops to 85 to 90 degrees; add more chocolate as necessary. (The bowl will feel slightly warm to the touch, and chocolate will appear smooth and shiny.)
To test tempering, dip an offset spatula in the melted chocolate, scrape excess off the back, and refrigerate 5 minutes; properly tempered chocolate will snap off of the spatula. Or dab a spot of melted chocolate on your lip; if it feels just slightly cool, then it's tempered. Use immediately. Keep chocolate over warm water to maintain temperature.
TEMPERING NOTES: Work in a room with low humidity, no warmer that 75 degrees. Use couverture chocolate, which contains at least 32 percent cocoa butter. As it melts, dark chocolate should not exceed 120 degrees (110 degrees for milk and white chocolates) or it may lose depth of flavor and burn. Leftovers can be remelted several times, but add a few ounces of unmelted chocolate to prevent bloom, a whitish surface cast. Water and condensation cause tempering chocolate to "seize", or become unmalleable. Bittersweet chocolate tempers between 85 and 90 degrees; milk and white chocolates temper between 82 and 83 degrees.