1.4 Maple Syrup Density Measurement. 1.4.1 Background; 1.4.2 Hydrometers; 1.4.3 Hydrotherms; 1.4.4 Refractometers . 1.4.4.1 Optical Refractometers; 1.4.4.2 Digital Refractometers; 1.4.5 Temperature Correction; 1.4.6 Instrument Calibration . 1.4.6.1 Hydrometers; 1.4.6.2 Thermometers; 1.4.6.3 Refractometers; 1.4.7 Collecting a Representative Sample
Because of this distinction, you may safely use fish even after the sell by date has lapsed. If there is a use-buy date on fresh fish, then it is recommended to either cook or freeze the fish by that date. Commercially frozen fish, if kept frozen, can be safely stored for 10-12 months.
Milk can stay fresh up to a week after its sell-by date; eggs can last three to five weeks at home (purchase eggs before their expiration or sell-by date and store the carton on the refrigerator shelf, where it is colder, not in the door). Use or freeze fresh meat and poultry within a couple of days of buying.