What is the issue?
Fish caught during long deep ocean passages are usually too large to be consumed by the average cruising couple. The largest part needs to be preserved and not wasted, but the problem is many long distance cruising vessels do not have any form of refrigeration.Why address this?
By having a technique to preserve food without refrigeration, it is possible to provide an alternative to tinned products and avoid the wastage of large quantities of excellent fish.How to address this?
It is possible to safely preserve fresh fish onboard by pressure canning. Pressure canning is essential for low-acid foods and fish falls into this category, as does poultry, meat and lots of vegetables.These can be processed in a jar at a temperature of 118°C, which can be reached in a pressure cooker/canner set between 10 – 15 lbs. The high heat destroys any bacteria present, eliminating the cause of spoilage. When properly processed, a vacuum seal forms within the jar so that new bacteria cannot contaminate the food.
Canning is a relatively easy process to undertake during a passage. The equipment required is not that expensive and it can be reused for general purposes. Likewise, once the initial expenditure has been made for the jars, sealers and pressure cooker, it is an economical way to process many different types of food for long-term storage.
Pressure Cooker and Canner
Photo: Courtesy of PRESTO
Firstly let's turn to that equipment. You will need a pressure cooker and some bottling jars. The high temperatures of 118°C necessary to kill the types of bacteria which may be present in fish can only be reached under pressure. We used a basic pressure cooker that we happened to have aboard. If using a pressure cooker that you already have, it must be in good condition and capable of attaining at least 10 lbs of pressure. Replace the gasket and safety plug if necessary. Be certain the vent or petcock is clear.Photo: Courtesy of PRESTO
If you do not have one, or have one that is a not up to the job, it is worth investing in a good one equipped with a pressure gauge. The pressure dial gauge gives an accurate reading so that it is easy to keep the pressure constant. A good pressure cooker is a good all-round investment for meals that need to come together quickly. It can do double duty as a large cooking pot which was very useful for the large stews we cooked before departing on long passages. It's also more efficient and better than a standard pot, as the foods retain much more of their nutrients and flavour.
Clip fastening jars
Photo: Courtesy of Bormioli
When it comes to the jars, use the type with the rubber seals and clip fastening lids as pictured. They worked perfectly for us and all we had to do was replace the rubber seals after use. Photo: Courtesy of Bormioli
Mason Jars
Photo: Courtesy of Ball®
The National Centre for Home Preservation however recommend 'Regular and wide-mouth Mason-type, threaded, home-canning jars with self-sealing lids are the best choice. They are available in ½ pint, pint, 1½ pint, quart, and ½ gallon sizes. The standard jar mouth opening is about 2-3/8 inches. Wide-mouth jars have openings of about 3 inches, making them more easily filled and emptied... With careful use and handling, Mason jars may be reused many times, requiring only new lids each time. When jars and lids are used properly, jar seals and vacuums are excellent and jar breakage is rare.'Photo: Courtesy of Ball®
The best instructions for the process will be found in the manual of your particular canner or pressure cooker. Make sure you use the times listed for canning fish and the correct pressure poundage. If you no longer have an instruction manual, look online or write to the manufacturer for a new copy.
The canning methods of your pressure cooker can be used in conjunction with the trusted, tested and safe guidelines provided by the National Centre for Home Preservation web page. The USDA 2015 revision of the Complete Guide Guide 05: Preparing and Canning Poultry, Red Meats, and Seafood is also available as a free PDF download.
This is an overview of our process so you can get an understanding of the broad principals involved:
1. Clean the fish down and slice off the fillets. Cut the fillets into container length pieces or meal-sized portions appropriate for a crew sitting.
2. Down below, whilst this is happening, boil all of the equipment for fifteen minutes to ensure that there is no bacteria in the jars or on the seals. Once the fifteen minutes are up, remove the jars and place on a clean surface, try not to touch the insides of the jars or lids and use tongs to remove the seals.
3. Place the fillets of fish in the jars loosely, with the skin side to the outside of the jar. Always leave a gap of about two centimetres at the top. This headspace allows the fish to boil during processing without disturbing the seal. We used to just cover the fish with water and add a bit of salt. Some people had quite specific recipes with vinegar, sugar, lemon and oil and omitted the water. There are many recipes to be found.
4. Get a clean cloth and wipe the rim of the jar to remove any spills and bits of fish then place the seal on the jar and close the lid using the snap lock fastener. Some people add some lemon juice to the canning water, up to 8 tablespoons, to counteract the fishy smell that may otherwise linger in the pressure cooker. As we were preserving within thirty minutes of catching the fish we never suffered from this problem.
5. Place the jars in the pressure cooker and cover with cold water making sure they are about 2 cm below the surface of the water. Make sure there is plenty of space around the jars so that they don’t crash into each other.
6. Close the pressure cooker and bring to the boil then place the weight on top of the steam outlet. Start timing at this point and boil for thirty minutes.
7. Remove the jars very carefully from the pressure cooker as they are extremely hot and place them on a surface covered with a clean towel. You can test that the seal is secure by removing the clip fastener on the clip lid jars and gently pulling on the lid. If it remains closed there is a closed seal but if it lifts the seal has not worked and you will need to pressurise it again using a clean seal.
8. If you find that the seals are not working after thirty minutes boiling time you may need to increase this by ten-minute intervals until you find the right time for your system.
The sealed jars will keep for months in a cool dark locker, for but be sure to test the seal before eating the contents and discard if it is broken.
There is something very satisfying about catching your own fish and to have to discard more than you can eat is heartbreaking. This method ensures that you can enjoy all of your catch even in a remote anchorage or on a passage where you have been unable to catch a fish.
With thanks to:
Jayne Harpur, Yacht Obsession.How to Can Fish in Jars
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