Caustic soda for the treatment of olives. Instructions for performing the deamarization treatment of table olives with caustic soda.
There caustic soda for olives table is employed in order to implement the process deamarization. The treatment ofoliveswithsodium hydroxidehas a limited duration: from 8 hours up to a maximum of 12 hours. For the process ofdeamarization of table olives mainly the caustic soda marketed in flakes is used, however, if you have caustic soda in drops or beads at home, it can be used equally.
What is caustic soda?
Caustic soda is a highly alkalizing chemical compound. Its chemical name issodium hydroxide(NaOH) and for its alkalizing properties it is considered a strong base. Just think that it is enough to dissolve 50 grams ofcaustic soda in a liter of water to obtain an aqueous solution with a pH of about 14!
Caustic soda is highlycorrosiveand must be handled with extreme caution. Before carrying out the olive treatment it is recommended to read the safety data sheet of caustic soda and follow the precautionary instructions indicated on the label. For all information on the use of caustic soda and its safety data sheet, I refer you to the articleCaustic soda, what is it for.
Caustic soda for the treatment of olives
The treatment of the olives with caustic soda lasts from 8 to 12 hours and ends when the soda has penetrated into the pulp of the olives for about 3/4 of the thickness.
Technically, the treatment of deamarization of the olives from the table ends when the pulp surrounding the stone, not yet penetrated by the sodium hydroxide, has a thickness of about 1-2 mm.
The treatment ofolives with caustic sodait should be monitored at regular intervals. How? Olives are taken and cut lengthwise up to the core, the color of the pulp is observed. The pulp attacked by caustic soda will become dark while the part not yet penetrated will remain white.
How much caustic soda to use for the amarization of the olives
The quantity to be used is minimal, we remind you that it is a corrosive compound so you must not exceed it for any reason. The concentrations of caustic soda to be used range from 1.8% to 2.1% approximately. In practical terms it is recommended to add 18 grams of caustic soda for every liter of water used. The water used must be at room temperature. By adding soda to the water, as stated, this will drastically increase its pH and an exothermic reaction will occur, that is, it will release heat.
How to carry out the deamarization treatment of olives with caustic soda
How much alkaline solution will you need?
First, calculate the amount of alkaline solution you need.
Take an earthenware, glass or plastic fruit squeezer container (not metal because the caustic soda would corrode it) and fill it with the olives to be treated. Fill it to the brim. Know that olives occupy approximately 65% of the total volume of the container, so only 35% of the volume of that container will be occupied by the alkaline solution.
Prepare a few liters of excess solution because you will need it for topping up.
Prepare the solution with caustic soda
The alkaline solution is prepared by dissolving the caustic soda in part of the water. While pouring the caustic soda, stir slowly. At this stage you must wear a protective mask for the airways and avoid breathing the fumes released by the exothermic reaction.
If you need 10 liters of alkaline solution. Separate the water into two containers. In one, pour 4 liters and that's where you need to add 180 grams of caustic soda, gradually. Then add the remaining 6 liters.
The olives must be completely covered by the solution containing caustic soda.
Monitor the deamarization process
During the treatment, constantly monitor the level of the caustic soda solution. The olives must be constantly immersed in the liquid, for this topped up with the solution prepared in excess at the beginning. The olives will absorb the solution therefore the level will gradually tend to lower, especially during the first hours of the treatment.
Monitor the absorption of caustic soda by engraving the olives as described above.
Finish the deamarization by performing 4 or 5 washes with drinking water in about 24-30 hours. Finally, put the olives in brine at a concentration of 8%. Basically 80 grams of table salt for every liter of water used for brine.
Soca caustic food, where to buy it
On Amazon a 225 g pack of food grade caustic soda can be bought at a price of 16.99 euros with free shipping. For all information, I refer you to the Amazon purchase page:pure sodium hydroxide, it is caustic soda powder.
It is commercially available in the form of whitish drops commonly calledcaustic soda beads, tablets or beads. In poor condition it is easier to manage (weigh and handle) but, regardless of the type of product you choose, remember that for food use it is necessary to choose asodium hydroxide very pure, "food grade".
You may also be interested in our related article on how to store salted olives