The most popular way to ship a few pounds or so of seafood across long distances (from state to state or even across country) is to utilize 1 1/2 inch to 2 inch thick foam shipping coolers (recyclable) coupled with either dry ice or gel packs for keeping the contents cold long enough to reach the destination while still thoroughly fresh and ready to prepare.
This arrangement is economical and proven reliable, plus the higher quality foam shipping coolers used for this purpose tend to be constructed for reuse, being generally leak resistant and well-formed. Also, gel packs are reusable, whereas dry ice evaporates into its original gaseous state.
NOTE: Do NOT use a cheap, easily breakable foam cooler typically purchased from department stores. They are NOT constructed for the kind of heavy-duty pounding expected of quality foam shipping coolers!
Gel Packs For Shipping Seafood
Gel packs (also known as PCMs, gel ice, and blue ice) are sturdy packs of ‘liquid feel’ gel refrigerant chemicals that freeze at 32 degrees Fahrenheit (0 degrees Celsius) like water, only when they get warm again they don’t melt all over the place because they are in sealed packs, completely reusable as long as the packs are not punctured or contaminated. You’ll want to consider packing enough gel packs to match the weight of your seafood – or maybe a bit more than that.
Dry Ice For Frozen Items
As a frozen gas (carbon dioxide), dry ice evaporates (sublimates) at a rate of about 5 to 10 pounds during a 24 hour period, so you have to plan for how much you’re going to need depending on whether you are doing an overnight or 2-day shipping (or longer). Obviously, shipping charges are going to get higher because of the increased weight per day, yet the effectiveness of dry ice makes it very popular. Sublimation starts immediately upon purchase, so if you’re not doing your packing while standing in a walk-in freezer or cold storage, then you definitely need to be quick about it. There are special labeling rules for dry ice packages, so be sure to ask your shipping provider.
When you pack your foam shipping cooler, it’s best to do so in a cold environment such as a walk-in freezer, or as close to cold as you can get. That way, your container is already cooled and your refrigerants and seafood are not in contact with heat. The closer your contents are to preferred temperatures before packing, the better your end result.
That said, the next question is…
“Should I Use Dry Ice Or Should I Go With Gel Packs?”
Well, that depends on the type of seafood and whether it’s still alive when you ship it and if you want it still living when it gets to the delivery point.
Let’s say you’ve just come in from a fun deep-sea fishing charter on a boat with a live well full of tasty red snapper, mahi-mahi (dolphin fish), trigger fish, or tuna. Perhaps you’ve been vacationing along the coast and decided to pick up a few pounds or so of lobster or other seafood at a local shop. In either case, you may want to enjoy some of that delicious fare when you get back home (or make it so that friends or relatives can enjoy it), which means you will need to ship that seafood in an expeditious manner with the least amount of expense that gets the desired result of a fresh arrival.
Do You Want Live Seafood To Arrive Alive?
In the case of live seafood such as freshly caught lobsters, you don’t want to use a refrigerant (or an amount of refrigerant) that will freeze them to death or cause them a degree of shock that results in their demise. To maintain the temperatures and conditions necessary to keep lobsters, mud bugs (crawfish) and such alive during expedited shipping, avoid the use of dry ice and go with the gel packs.
Do You Want Your Seafood To Remain Frozen?
Best to pre-freeze your contents in that case, but if you haven’t the time or resources, ensure to package so that you’ve enough refrigerant to lower the temperature enough to do the job for you, maintaining a proper temperature range during the entire shipping trip.
Dry ice is excellent at keeping seafood frozen, but you can effectively do the same thing by pre-freezing the appropriate number and weight of gel packs. The advantage of gel packs is that they are reusable.
If you do not want your goods to be frozen, you can adjust the amount of refrigerant, shipping time, or how much insulation you place between the refrigerant and seafood. As an example, some people will place unfrozen gel packs as a barrier between their seafood and the frozen gel packs. That way, the frozen gel packs cool the unfrozen ones which in turn chill the seafood itself.
So, in your shipping plan, take into consideration the time frame (overnight, 2-day, or longer), shipping charges incurred due to weight (you’ll need more dry ice which may increase your package volume causing you to purchase a larger foam shipping cooler, cardboard container box, etc.), and whether you want your contents frozen, cold, or merely chilled. These things will determine whether you use dry ice or gel packs and how much of either when shipping seafood in foam coolers across long distances.