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Filming & Etching on Glassware
Submitted by Lorene Bartos, UNL Extension Educator
Cloudiness or filming on glassware after it has been in the dishwasher can be a problem. This may happen after several washings and appears as a white film and the cause may be hard water. Hard water filming many times can be removed. However, if etching occurs it is a permanent film. Etching, in the beginning stages may be identified by an iridescent look – shades of blue, purple, brown or pink seen when the glass is held at an angle in the light. The surface will appear frosted or cloudy in advanced stages of etching.
Filming may be cause by:
(1) Hard water and not enough detergent. This combination may leave hard water minerals that dry on the surface of the glassware creating a film. Unremoved food soil may also cause filming.
(2) Low water temperature. The water temperature should be 140 degrees F as it enters the dishwasher. Check the water temperature by placing a candy or meat thermometer in a glass and letting it fill with water from the hot water faucet in the kitchen sink. Let the water run until the temperature stops rising. If it is not 140 degrees F, adjust the water heater. If the dishwasher is not near the hot water heater, let the water run before starting the dishwasher this clears the line of cold water.
(3) Not using a rinse additive. A rinse additive such as JET-DRY improves the sheeting action of the water. Use liquid JET-DRY in the rinse dispense. If the dishwasher is not equipped with a dispenser, hang a basket of solid JET-DRY in a back corner of the lower rack.
To remove filming, soak glasses approximately 15 minutes in undiluted white vinegar. Rinse and dry. Or, wash the glasses in a basin of water using a generous amount of dishwasher detergent (wear rubber gloves to protect your hands from the strong detergent solution).
Etching may be prevented by:
1. Adjusting the amount of detergent according to water hardness. See chart below.
2. Lowering the water temperature so it enters the dishwasher at approximately 140 degrees F. Do not use a water heating option such as Temp Boost, Power Boost or Power Scrub.
3. Use the no heat Energy Saver dry cycle, if you have one.
4. Do not manually pre-rinse dishes before loading in dishwasher. Pre-rinsing prior to loading to remove all food soil increases the alkaline concentration of the dishwasher detergent.
This chart shows the amount of detergent to use for each wash according to water hardness (measured in grains per gallon). Lincoln's water is 11.1 grains per gallon. One tablespoon of detergent per wash is the minimum amount recommended.
0-3 Grains Hardness...........1 Tablespoon - (fill dispenser cup Â¼ full)
4-6 Grains Hardness...........2 Tablespoons - (fill dispenser cup Â½ full)
7-9 Grains Hardness...........3 Tablespoons - (fill dispenser cup Â¾ full)
10-12 Grains Hardness.........4 Tablespoons - (fill dispenser cup completely full)
If the water hardness if over 12 grains, it may be necessary to use the Low Energy wash cycle and fill both cups completely full of detergent. If you have soft water, used in the dishwasher, adjust detergents accordingly as less detergent is needed with soft water.
Most times dishes do not need to be rinsed prior to being washed in the dishwasher. Scrap or wipe off excess food on dishes or pot and pans. The dishwasher will work better when the dishes are not completely clean when put in the dishwasher. Save water and energy by following these suggestions.
Contact InformationUniversity of Nebraska-Lincoln in Lancaster County
Web site: lancaster.unl.edu
444 Cherrycreek Road, Suite A, Lincoln, NE 68528 | 402-441-7180