junket is, that led us to rennet. Since Little House in the Big Woods, the girls have always asked me if cheese is made with the stomach of a calf, or if that was only in the old times and not now.This is what you can read if you click on rennet in Wikipedia,
Traditional methodDried and cleaned stomachs of young calves are sliced into small pieces and then put into saltwater or whey, together with some vinegar or wine to lower the pH of the solution. After some time (overnight or several days), the solution is filtered. The crude rennet that remains in the filtered solution can then be used to coagulate milk. About 1 gram of this solution can normally coagulate 2 to 4 liters of milk.
This method is still used by some traditional cheese-makers, e.g. in Switzerland, Greece, France, Romania, Italy, Sweden, United Kingdom and Alp-Sennereien in Austria.
Modern methodDeep-frozen stomachs are milled and put into an enzyme-extracting solution. The crude rennet extract is then activated by adding acid; the enzymes in the stomach are produced in an inactive form and are activated by the stomach acid. The acid is then neutralized and the rennet extract is filtered in several stages and concentrated until reaching a typical potency of about 1:15,000; meaning 1 gram of extract can coagulate 15 kg (15 litres) of milk.
In 1 kg of rennet extract, there are about 0.7 grams of active enzymes – the rest is water and salt and sometimes sodium benzoate, E211, 0.5% - 1% for preservation. Typically, 1 kg of cheese contains about 0.0003 grams of rennet enzymes.
Much to their disgust, rennet is still employed in the making of cheese! They now prefer to reminisce about the time at the park when they made ice cream than to keep discussing cheese!