Practical example: pH-control in the production of aspic and aspic sausage
In the production of aspic, besides the artisanal production of animal constituents (paws and rinds), there is also the use of industrially produced gelatin. It consists largely of similar animal ingredients but is produced industrially.
The so-called bloom number characterizes gelatin and defines the subsequent firmness of the aspic. Which means: the higher the bloom number is, the higher the firmness. The reference values are the following: bloom numbers < 160 are defined as lower, the bloom numbers > 220 are defined as higher.
However, the other factors also play an equally important role in the firmness of the subsequent aspic.
- Amount of the added gelatin
- Bloom number
- Temperature of the finished jelly, as well as the heating and cooling process during the manufacturing
- the pH value
In the production of aspic, an edible gelatin is first swelled in cold water and then heated carefully at 50-60 ° C with stirring. During this process the gelatin dissolves. In case of aspic powder the swelling can be omitted and the water can be heated more (up to 80 °C). Spices and depending on the product different amounts of vinegar are added to this gelatin mass. In this case, the added amount of the vinegar influences the pH value of the gelatin mass.
Because of the hygienic reasons, an acidic pH value is always an advantage; depending on the type of aspic and also for the reasons of taste. However, the pH has a direct influence on the firmness of aspic. So the aspics with the pH range of pH 3-4 have got a 10-20% lower firmness than the aspics with the pH 5. In order to reach the desired aspic firmness in each product, depending on the used vinegar amount gelatin with an appropriate bloom number must be used. Also, the vinegar can be added to the aspic shortly before the end, in addition to the gelatin. In these cases, the gelatins with lower bloom number can be used then. Depending on the subsequent aspic the optimum "process conditions" regarding the type of gelatin, temperature (exposure time) can be found. The pH defines the characteristics and must be measured in the working process.