Article: To clean aluminum baking trays, pots, and other bakeware, mix water and vinegar in equal amounts.  For instance, you might mix half a cup of water with half a cup of vinegar.  Bring the mixture to a boil inside the bakeware item you want to clean.  For deeper pots and trays this will require a larger amount of vinegar and water.  The mixture, in this case, can be boiled on the stovetop. For shallow bakeware items like cookie sheets, you might have only a thin layer of water and vinegar in the pan.  You’ll probably have to boil this mixture in the oven.  Set the tray in the oven to a temperature of about 212 degrees Fahrenheit (100 degrees Celsius). If you wish, you could throw in a whole sliced lemon into your boiling mixture.  The natural acidity of the lemon juice works wonders on aluminum bakeware. Once the mixture gets boiling, turn the heat off and wait 15-20 minutes for it to cool.  Dump the mixture out and wash the bakeware item with warm, soapy water in the sink.  Scrub the pan with a sponge and/or scrubbing pad.  Use vigorous circular motions to remove the stain. If you don’t want to clean your aluminum bakeware with vinegar and water, slice a lemon lengthwise into four equally-sized wedges.  Dip the fruit sides (not the peel) in salt.  The salt should stick to the juicy flesh of the lemon.  Grip the lemon wedge by placing your thumb on one end and your ring and middle fingers on the other end. Apply the salted fruit to the stain and scrub it away with a gentle back-and-forth or up-and-down motion. When you’ve removed the stain, wash the bakeware item with warm, soapy water. If salted lemon slices and vinegar alone don’t work against your stained aluminum bakeware, you could try a cream of tartar cleaner.  Simply mix one quart of water, ½ cup of vinegar, and 2 tablespoons of cream of tartar.  Boil the whole mixture inside the stained bakeware item.  Let the mixture boil for 10 minutes, then turn the heat off, dump the solution out, and wait 15 minutes.  Scrub the bakeware item clean in the sink with warm, soapy water. Use steel wool.  Move it back and forth across the surface of the pan.  Do not be too vigorous with the steel wool, as it can scratch aluminum.  If you cannot easily boil the mixture in the bakeware itself, you could boil it in a separate pot, then wait for the mixture to cool and dip a sponge in it.  Use the sponge to scrub the stain away. Alternately, you could pour a small amount of the solution in a shallow bakeware item and boil it in the oven at a temperature of about 212 degrees Fahrenheit (100 degrees Celsius) for 10 minutes.
What is a summary of what this article is about?
Use water and vinegar. Use salt and lemon slices. Use cream of tartar.