Ascorbic and citric acids are two organic acids used as preservatives in canning and other culinary applications. Both are sometimes used in the same way and have a connection to citrus fruit, which makes it easy to get them confused but there are some crucial differences. In this SPICEography Showdown, we will look at what is special about these food additives, how they are used and how each of them can work in your cooking.
How is ascorbic acid different from citric acid?
The first main difference is the chemical makeup of each compound. Ascorbic acid is another name for vitamin C. It is a water-soluble compound that is also sensitive to heat, which is why your body does not store it. Your body uses ascorbic acid’s antioxidant properties for protecting and repairing its cells. While citric acid is a weak organic acid just like ascorbic acid, it is not a vitamin and is not a good source of nutrients. It does have antioxidant properties but it is a weaker antioxidant than ascorbic acid. It has a positive effect on nutrition in that it can help to make certain minerals more bio-available. Those minerals include magnesium and calcium.
Citric and ascorbic acid also differ in cost. Of the two, you are more likely to see citric acid listed as a preservative because it costs less than ascorbic acid and is easier to find.
While both preserve foods by lowering pH (which helps protect food from microbes), they are used differently. Ascorbic acid functions entirely as a preservative and has no effect on flavor. Citric acid has the ability to make food more acidic while also altering its flavor. The antioxidant properties possessed by each helps to prevent browning from oxidation.
These acids also differ from each other in the area of flavor. Ascorbic acid is not normally used to enhance food flavors as it is bitter. Citric acid is tart and is often used as a souring agent in dishes that need increased acidity.
Can you use ascorbic acid in place of citric acid and vice versa?
Even though ascorbic acid and citric acid are effective preservatives, their different properties keep them from being interchangeable in every instance. You can use citric acid to replace ascorbic in applications where you want to prevent browning but not when you want to condition dough. Ascorbic acid helps to enhance the growth of yeast in bread dough and to increase the dough’s volume. This results in bread that has a finer texture.
Citric acid will not provide any of these benefits in dough; however, it can be used as a flavor additive in a few cases. One example is if you want an especially acidic sourdough flavor, but it will do nothing for the texture of the finished product.
Ascorbic acid is the better option if you want to keep fruit from browning due to oxidation and works without affecting your food’s flavor. When using citric acid in place of ascorbic acid, note that you will be you will be increasing the tartness of the food, which may not be desirable in all cases.
When should you use ascorbic acid and when should you use citric acid?
Along with using it to condition your dough and to prevent browning, use ascorbic acid to reduce nitrosamine formation when you are curing meat. Use citric acid to add sour flavors to a dish and to help with preservation by creating an environment that is too acidic for microbes.