My last article talked about the basic principle of taking accurate temperatures. Such a simple and easy way to monitor and to indicate whether you have acheived maximum processing results. Before we can start the first major processing step( thawing ), we will have to discuss fish sizing as it is such a significant factor in achieving all our goals.

What is the first step in processing and the key to starting things on the right track?

To get optimum processing to achieve maximum processing goals, it is important to start right from the beginning. One of the most overlooked steps in processing tuna or other fish, is to accurately size each fish. The most common measurement used for tuna sizing is weight. Your fish should all be grouped by weight category which then will determine the various processing times for each stage. If your fish weights are all mixed, then this will result in over and under processed fish in your batches. Most plants say that they size all of their fish, but from my experience it is not done very accurately and it has always been treated in that manner as not so important. This is because it is time consuming, and requires more labor. In reality, if this is done accurately from the beginning, then all your fish will have very consistent, uniform temperatures and you will benefit substantially in the proceeding processing steps. Accurate sizing along with consistent temperatures will assure optimized processing, eliminating over and under processing. This may appear to be insignificant but at the end of the day when you look at the recovery, yield and quality grading, there will be a notable difference. By the end of the month, your monthly reports will show a very nice gain in recovery, yield, and quality.

Some of the larger well known tuna processors use an automated type of sizing system which requires conveyors and an electronic load cell system. Others will use a mechanical spring scale or digital scale and will weigh each fish manually. Some plants will just look at it and estimate the size category and toss it in the appropriate bin. I have also seen a few roller graders which are normally used for fruits and vegetables. The rollers are spaced in different increments and the fish will fall through the space between the rollers depending on the width of the body. All of these methods will work but some more better  than the other, and the cost can vary quite a lot. It would depend on the accuracy you want and your preference in determining which method to select.

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