How to Test the Freshness of Butter

Butter has a shelf life of around 3 months for unsalted and 5 months for salted butter. However, depending on storage conditions prior to and after purchase, the butter can deteriorate sooner and impart a rancid flavor to your baking and food. Here is how to test if it is still fresh.

Steps

1
Check the expiry date on the packaging.^{[1]
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Research source} This should be the first indicator of the butter's freshness. Close to the use-by date or past it, and the butter is less likely to be fresh.
2
Check how the butter has been stored. Butter should not be exposed to light during storage. This is why it is thoroughly wrapped and it is best if wrapped in foil. If it has been unwrapped, it risks turning rancid faster than even the suggested use by date.^{[2]
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3
Cut a small slice of butter from the block or stick.^{[3]
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Research source} Look at the color. If the inside of the butter is the same as the outside, it is still fresh. However, if the inside of the butter is lighter than the outside of the butter, this means it has oxidized. As such, the butter is no longer fresh.^{[4]
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4
Smell the butter. Some people are better at using this method than others; if you use and consume butter a lot, it should be obvious when butter no longer smells fresh.^{[5]
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- A small taste test can also tell you much; it will taste sour or bad if it is no longer fresh.