Foodservice Sanitation 381Table 21–1Dishwashing Difficulties and Solutions
Symptom Possible Cause Suggested Solution
Soiled Insufficient detergent Use enough detergent in wash water to ensure
dishes complete soil removal and suspension
Low wash-water Keep water temperature within recommended
temperature ranges to dissolve food residues and to facilitate
heat accumulation (for sanitation)
Inadequate wash and Allow sufficient time for wash and rinse operation to
rinse times be effective (time should be automatically con
trolled by a timer or by conveyor speed)
Improper cleaning Unclog rinse and wash nozzles to maintain proper
pressure-spray pattern and flow conditions; overflow
should be open; keep wash water as clean as
possible by pre-scraping gross soil from dishes, etc.;
change water in the tanks at proper intervals
Improper racking Verify that racking or placement is done according to size
and type; silverware should always be presoaked and
placed in silver holders without sorting or shielding
Films Water hardness Use an external softening process; use the proper deter-
gent to provide internal conditioning; check temperate of
wash and rinse water (water maintained above recom-
mended temperature ranges may cause a precipitate film)
Detergent carryover Maintain adequate pressure and volume of rinse water;
worn wash jets of improper angle of spray may cause
wash solution to splash over into final rinse spray
Improperly cleaned or Prevent scale buildup in equipment by adopting frequent
rinsed equipment and adequate cleaning practices; maintain adequate
pressures and volume of water
Greasy Low pH; insufficient Maintain adequate alkalinity to saponify greases; check
films detergent; low water cleaning compounds and water temperature; unclog all
temperature; impro- wash and rinse nozzles to provide proper spray action
perly cleaned (clogged rinse nozzles may also interfere with wash
equipment tank overflow); change water in tanks at proper intervals
Foaming Detergent dissolved or Change to a low-sudsing product and reduce the solid
suspended solids content of the water
in water
Streaking Alkalinity in water; Use an external treatment method to reduce alkalinity
highly dissolved within reason (up to 300–400 ppm); selection of a proper
solids in water rinse additive will eliminate streaking; above this range,
external treatment is required to reduce solids
Improperly cleaned or Maintain an adequate pressure and volume of rinse
rinsed equipment water; alkaline cleaners used for washing must be
thoroughly rinsed from dishes
Spotting Rinse-water hardness Provide external or internal softening; use additional rinse
additives
Rinse-water temperature Check rinse-water temperature; dishes may be flash-drying,
too high or too low or water may be drying on dishes rather than draining off
Inadequate time between Change to a low-sudsing product; use an appropriate
rinsing and storage treatment method to reduce the solid content of the water
Continues