in ancient Rome the legionaries fermented fish in salt to preserve it for many months. This practice is still in vogue in Southeast Asia to produce fish sauces. this thick and very flavorful liquid is a superb large carp attractant that you can easily produce at home inexpensively.
The ingredients are:
3 kilograms of uncleaned sardines or anchovies (they must contain their entrails which are the source of the enzymes necessary for the reaction).
you can use any small fish even freshwater ...
you need a kilogram of sea salt (the proportion must be 1/3 of the weight of fresh fish).
Finally, a glass container with a cap large enough to comfortably contain the raw material. some space has to be left over.
starting from the bottom of the container alternate layers of minnows cut into small pieces and salt. You have to finish with a layer of salt.
At this point close the jar and let it rest for 3-4 days. The optimum temperature is 30 degrees celsius, but you absolutely must not go below 20 degrees, otherwise enzymatic fermentation will not take place.
At this point, open the jar and mix the contents well every 3-4 days. you will see that more and more liquid will form and that the pieces of fish will melt. You will never smell bad.
after a month you can blend everything creating a homogeneous sauce. From this moment the liquid is stable and you can use it to make boilies in dosages from 50 to 100 milliliters per kilogram of mix. The sauce is stable and can be kept for many months in a cool, dry place.
I leave you the photos of the process in the gallery.