Where to Buy Food Grade Potassium Nitrate?
If trying to find food grade Potassium Nitrate (commonly known as “saltpeter”) locally, your best bet is to check stores that sell spices and herbs (such as the Penn Herb Co. in Philadelphia, PA). Other good places to inquire are provisions companies and restaurant supply stores – particularly those for butchers and meat processing (such as the Craft Butchers Pantry in Des Plaines, IL).
It’s important to note that there are industrial uses for potassium nitrate. So when buying saltpeter for making corned beef, thickening soup, or any other food preparation – you should make sure the product is the substance you expect, does not have unwanted additives, and is food grade (intended to be used in preparing food for human consumption). Also, ensure you are using this substance safely.
(Note: Potassium Nitrate can be hard to find, particularly for use in food. For this reason, many people stick to substitute products intended for use in cooking – such as Morton Tender Quick, which contains 0.5% Sodium Nitrate as well as 0.5% Sodium Nitrite, which are also used for curing meat.)
What is Potassium Nitrate?
Potassium nitrate is a strong oxidising agent and a white to dirty gray solid. Food grade version is colourless, odorless and has a salty taste. It is water soluble. It is popularly known as saltpeter, which actually is a mixture of many nitrogen-containing compounds. This compound is a natural source of nitrogen.
Uses of Potassium Nitrate in Food
The most common and important usage of this particular compound has been in preserving food, particularly meat. Potassium nitrate has been used for meat preservation (salted or “salt-cured” meat) for centuries. It is commonly used in the production of corned beef through brine.
In meat preservation, the presence of nitriles and nitrates have been found to have a inhibitory effect on the growth of Clostridium Botulinum, which causes the dangerous food borne illness ‘Botulism’. Although rare, Botulism can cause paralysis, organ paralysis, and death.
Cheese preparation also involves potassium nitrate as a preservative, as the presence of bacteria can cause problems in fermentation. Potassium nitrate counteracts these bacteria and provides conditions for smooth cheese processing – however, too much of the compound can cause discoloration in cheese, such as reddish streaks, and an unacceptable “off” taste.
Food grade saltpeter is also used as a thickener in some recipes, especially in soups (e.g. Okra soup). It can be used to soften food, reducing the cooking time. When meats are treated with potassium nitrate they soften, allowing water to more easily enter between the tissues. This allows for even heating, resulting in a more uniform in texture and flavor.