quote:Originally posted by tortuga
On my last boat I actually had a full size freezer. I got this great idea of freezing the fish as soon as they were caught. So, bonked, bleed, rinsed, bagged, and in the freezer they went. Got the fish home and used a saw to cut them up in steaks. Wow, how fresher can you get?
Well, I only did that once… worst tasting toughest eating fish, I ever had and ended up with a lot of crab bait. And, I didn't have a clue as to why! Well here is what I found out. I froze them pre-rigor mortis.
Here is what I found out.
quote:How do you avoid ending up with a stiff one?
Actually ending up with a "stiff one" is good, referring to fish of course.
"When filleting is delayed until after the whole fish has gone into rigor at a low temperature, most of the problems of shrinkage are avoided, but nevertheless there are some disadvantages."
"In addition, gaping may be caused by forcibly straightening bent fish before cutting them…"
"Frozen fillets taken from post-rigor whole fish are normally of uniformly good quality, provided the whole fish has been properly handled and kept chilled…"
quote:The longer you play a fish the more lactic acid is released which is not good but what do you do if your fishing 200+'?
I don't know about the "lactic acid" issue and don't think is a factor, but the longer you play a fish the better.
"Degree of exhaustion: In the same way, fish that have struggled in the net for a long time before they are hauled aboard and gutted will have much less reserve of energy than those that entered the net just before hauling, and thus will go into rigor more quickly."
quote:And why do fresh ling sometimes curl up on the Q and end up being a bit tough?
That would be created by "Thaw rigor"
Thaw rigor</u>
"When muscle is frozen pre-rigor and kept for a short time in cold storage, it is still able to contract and go into rigor after thawing. This is known as thaw rigor and, when the thawing is done rapidly at a high temperature, the muscle can then suffer from the defects associated with high temperature rigor.
Thaw rigor is rarely a problem in thawed whole fish because freezing and cold storage have usually sapped the energy reserves sufficiently to weaken the contractions in the muscle; the skeleton restrains the muscle but the stresses are insufficient to break the connective tissue. If damage is seen at all in thawed whole fish, it usually occurs near the tail, where thawing is most rapid.
However, when pre-rigor fillets are thawed, the muscle is free to shrink as soon as the ice within the flesh has melted, and the fillets become shrunken and corrugated and lose a large amount of drip. The effects are most severe when the pre-rigor muscle is cooked from the frozen state…"
"The texture will be tough and stringy and drip loss will be high… The effects of thaw rigor are more noticeable when single fillets or small portions are thawed, rather than blocks of fillets."
Can thaw rigor be prevented?
"Thaw rigor is uncommon in commercial practice but, when it is met with, the ill effects can be avoided fairly simply. The simplest way is to extend the cold storage time of the stock of pre-rigor fish. Provided they are kept for at least eight weeks at minus 20° F, the flesh has time to pass through rigor in the frozen state; this has no bad effect on the quality of either whole fish or fillets, since they are both held rigidly enough while frozen to prevent the muscle from contracting.
If the fish have to be taken out of store in less than eight weeks, they should be thawed slowly at room temperature; in this way rigor is completed while the fish are in a semi-frozen state, thus preventing severe contraction of the muscle."
quote: Anything a guy could do besides bleed it and get it on ice?
First think and most importantly, don't ever expose or let the fish set in "fresh ice" or "fresh water"
Controlling the effects of rigor
"The safest and most reliable way of avoiding the undesirable effects of rigor is to keep the fish chilled at every stage before freezing. Provided the fish pass through rigor at a low temperature, the effect of rigor on quality will not be serious.
Having said that, it is necessary to mention the possibility of accelerating the rigor process by raising the temperature of the fish under carefully controlled conditions. It is possible by warming a fish to shorten the time it takes to go into, and pass through, rigor…, but only at the expense of some loss of quality due to the higher temperature, and the possibility of increased gaping. As explained earlier, the maximum temperature for accelerating rigor in cod is 63°F if irreparable damage is to be avoided. On the whole…, but to keep the fish chilled until they enter the freezer."
Summary
"Rigor changes occurring in fish before it is frozen may affect the quality in three main ways:
1. toughness and high drip loss in frozen whole fish or fillets;
2. gaping in fillets taken from frozen whole fish; and
3. shrinkage of frozen fillets.
These undesirable effects can be reduced or prevented by:
1. keeping the fish cool, particularly before it goes into rigor;
2. handling it carefully when in rigor; and
3. freezing fillets taken from pre-rigor fish as soon as they are cut.
Careful treatment of the fish before and during rigor will result in a higher quality frozen product…"
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