Tie peppercorns, mustard seeds and pickling spice in a square of cheesecloth, creating a spice bag. Set aside.

Combine orange zest and juice, rhubarb, brown sugar, vinegar, onions, raisins, garlic, and ginger in a large stainless-steel saucepan. Bring to a boil over medium-high heat, stirring constantly. Reduce heat and boil gently, stirring occasionally, for 45 minutes.

Add curry powder, allspice, and reserved spice bag; stir well. Boil gently, stirring frequently, until thick enough to mound on spoon, about 30 minutes.

Prepare water canner in the meantime. Heat jars in simmering water until ready for use. Do not boil.  Wash lids in warm soapy water and set bands aside.

Using a jar lifter, grab one canning jar, place on a towel or wooden cutting board, then LADLE hot chutney into hot jars leaving 1/2 inch headspace. Remove air bubbles (this headspace tool is perfect for this). Wipe rim. Center hot lid on jar. Apply band and adjust until fit is fingertip tight.

Process in a boiling water canner for 10 minutes (processing time starts once water is boiling), adjusting for altitude. Turn off heat, remove lid, let jars stand 5 minutes. Remove jars and cool. Check lids for seal after 24 hours. Lid should not flex up and down when center is pressed.