Salting or Brining of the fish (6)

There is a more detailed Brine Strength Table available as a pdf here.

The recommended brine strength for most products is 70-80 degrees. Using higher strength or saturated salt solutions may result in salt crystals appearing on the surface of the smoked fish which present as unattractive white patches. In many cases, fish absorb salt more evenly throughout the flesh if a lower salt concentration brine is used but the brining process then takes longer. Commercially a compromise is necessary and experience suggests that using a 70 degree to 80 degree brine is best.

Whilst it is important from a hygiene point of view to make a fresh brine on a daily basis, it is also necessary, from time to time during the working day, to check the strength of the brine.

*When adding salt to water, the resulting brine will be of greater volume. Sometimes the amount of extra volume can be a surprise. Column D shows that 1000 litres of water made up to a 80 degree brine will produce 1100 litres of brine.

This is why the amount of salt added to 1 litre of water, and the amount of salt in 1 litre of brine are not the same. Simple calculations of how much water or salt to add to adjust brine strength are often slightly out. With a little more thought you can calculate to a much greater degree of accuracy just how much more salt or water you need. Why not try our worked examples below?

** Brine too weak - add salt.

As you will not alter the total amount of water in your brine, work out how much water is in your brine using column G.

Work out the difference (per litre of water) in salt needed to make up your target brine compared to your actual brine strength using column C.

Multiply this amount of salt by the litres of water in your brine and add that salt.

** Brine too strong - add water.

The total amount of salt will stay fixed, so work out how much salt is in your brine using column H.

Work out how much water would be needed to make up your target brine using the salt already in your over strength brine (column C).

Work out how much water is already in your brine (column G) and add the difference.

Here is an example.

1200 litres of brine should be 70 degrees but is actually 90 degrees. You would add 403 litres of water to adjust to a 70 degree brine.

1200 litres of 60 degree brine should have been 80 degrees in strength. How much salt should you add to make it back up to 80 degrees?

To find out how to calculate adjustments print off these two documents and have a go at the worked examples.

Brine calculations - worked examples

Table of brine characteristics

And if you want to have a go at making and adjust brine strengths with real salt and water, print off and have a go at this practical exercise.

You will need a measuring jug(s), 750grams salt, kitchen scales (ideally digital), (and a salinometer would help).

If you don't have a salinometer or brineometer to check brine strength then try this:

weigh 1000cc of brine carefully. use column E in the characteristics table to get the approx. strength in degrees.