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.
Fresh fish may be stored one to two days. Most fresh seafood should be used the day you buy it. After two days it's best to check it to be sure it's still good and then freeze it till you plan to use it. Place it in an air tight container for the best results.