Alum powder is made from alum, which has been widely used since before recorded history. Despite being the length of time it has been in use, it was not a culinary ingredient until relatively recent times. The name is short for potassium aluminum sulfate. It was well known as an ancient antiseptic with deodorizing properties.
Another important early recorded application for alum was as a fixative for dyeing textiles both prior to and during the ancient Egyptian civilization. Along with dyeing, Herodotus stated that it was used in ancient Egypt for mummification.
In addition, historians believe that Egyptian papyruses were hardened with alum. Roman historian Pliny the Elder wrote about alum’s effectiveness as a cosmetic and as a medicine. It is likely that alum was the first underarm deodorant in history. In the 12th century, alum was still being used medicinally and had a variety of applications, some of which were obstetric in nature; others related to dentistry. It was still being used at this time for dyeing. In fact, many of the recipes used by dyers today are very similar to those that were applied then.
Alum is found mostly in desert climates and in the Old World, it was imported from North Africa and from countries around the Mediterranean sea along with other dry regions.
In the 17th century, the British would develop a reliable method for extracting alum from shale, and this allowed them to be more self-sufficient.
Alum was used by British bakers in the 19th century as a means of adding bulk to the ingredients in bread and to give loaves bread a better appearance. The result was that the baker was able to charge more for the resulting product.
Alum powder was used as a less expensive acidic component in baking powder starting in the 19th century; it was a cheaper alternative to cream of tartar. The use of alum was earnestly opposed by established baking powder manufacturers who used cream of tartar in their blends. This opposition resulted in what has been termed the baking powder war, which continued into the 20th century. During this war, legislatures were bribed to pass laws that banned the sale of alum baking powders. Eventually, the companies that used alum won and (for the most part) are the ones whose products you see on grocery store shelves today.
Alum powder flavor profile
Alum powder has an astringent taste that some liken to water that has been treated with chlorine. It is worth noting that many people find this taste pleasant.
Health benefits of alum powder
Alum powder is not a significant source of any nutrients; however, it can have health benefits such as:
- Purifying drinking water: Alum powder can work as a flocculant, which means that it causes contaminants to clump together and be more easily filtered out of water.
- Helping to induce vomiting: Alum powder can function as an emetic; you can administer it to provide emergency treatment if someone is thought to have ingested something toxic.
- Relieving muscle cramps: Alum powder is sometimes combined with turmeric to treat muscle pain and spasms.
Alum powder shows up in baking powder and in maraschino cherries, but one of its most important applications for home cooks is in pickles. Alum powder can also be added to homemade pickles to make them crisp.