We’ve seen this video on social media warning viewers to “wash your cheese.” One post on X has over 13 millions impressions.

The video depicts a packet of pre-shredded cheese being washed over a sieve to reveal cloudy residue and small white lumps in the resulting water. Other posts and replies suggest that chemicals or impurities exist in such products, and that washing cheese is a necessary precaution before consuming it.

We looked closer at the ingredient list of different shredded cheese products to find out, firstly, what causes the cloudy residue and, secondly, if it is a food safety risk. The cheese used in the video – from the brand Sargento – lists 3 ingredients aside from the cheese itself: Potato Starch, Powdered Cellulose, and Natamycin.A look at other brands’ shredded cheese products also reflects a similar ingredient list –cheese, a preservative to prevent mould (typically Natamycin), and an “anti-caking agent.”

Based on our research and clarifications by brands such as Sargento and Tillamook, it is the “anti-caking agent” that produces visible white residue after shredded cheese is rinsed.Often used anti-caking agents include potato or tapioca starch and cellulose, which are added in powder form in small amounts to prevent caking and clumping of the cheese inside the packaging. Cellulose, which is derived from plant fibre, is a commonly used food-safe ingredient that coats the cheese, preventing excess moisture. It is this powder (or other starchy powders) that can be seen rinsed off in the video and left in the excess water.

Anti-caking agents are typically only used in shredded cheese that has been shredded – not generally in blocks or slices. The general usage of “cheese” in the video, therefore, has the potential to be further misleading.

We give this claim a rating of false. Cellulose and other “anti-caking agents” are not harmful ingredients and removing them from shredded cheese does not render the cheese safer or cleaner. Conversely, they serve a key function in ensuring that the shredded cheese remains in its original form without degrading. It is therefore not necessary to “wash your cheese” before consumption.

While being ingredient-conscious and aware of the food we consume remains important, it is equally important to fully research food-related claims such as this one. While video-based claims in particular are often effective in stirring up immediate worry or concern, it is prudent to be cautious of claims that fail to provide sources or name specific issues beyond “impurities” or “danger.”