Can cashew milk go bad?

In this brief study, we will answer the question, “Can cashew milk go bad?” Additionally, we will address the shelf life and storage characteristics of cashew milk.

Can cashew milk go bad?

Yes, cashew milk can go bad. If you purchase cashew milk in the market, it can go bad beyond the expiration date, due to improper handling, or after a few days of being opened. 

If you have freshly made cashew milk, it lasts a few days in the refrigerator before going bad. Homemade cashew milk should never be stored outside of the refrigerator.

The truth is that cashew milk is a highly perishable food, and I will tell you why.

Cashew milk contains mostly water (about 83%), proteins, fat, carbohydrates, and minerals such as calcium, potassium, iron, magnesium, and phosphorus [1].

Previous studies also revealed that fat in cashew milk is predominantly unsaturated [2]. Moreover, the pH of cashew milk ranges between 6.5 (e.g. sugar) [3].

All of these characteristics make cashew milk a rich environment for microbial growth. Microorganisms, like us, require water and nutrients to multiply. Neutral or closely neutral surroundings (pH of about 7) are also preferred. 

Due to the high content of unsaturated fat, cashew milk is also susceptible to oxidation reactions that may lead to rancidity [2].

Rancidity is the result of a chain of reactions that can take place when unsaturated fat in cashew milk enters into contact with air, leading to the formation of off-flavors and off-odors associated with rancidity [4]. 

Light and heat may boost oxidation reactions, so protecting the cashew milk from them helps extend the shelf life of this product with regard to fat degradation.

How long can cashew milk last?

The shelf life of cashew milk depends on whether it has been exposed to any preservation method, such as pasteurization or sterilization. Moreover, it also counts if you have opened the pack or not.

Currently, cashew milk is mostly marketed as a shelf-stable product, which means that unopened packs of cashew milk can be stored at room temperature. 

This is possible because cashew milk undergoes sterilization to make the product commercially sterile, and aseptic packaging in cartons to protect it from light, oxygen, and recontamination. 

Preserved like this, while unopened, brands label that cashew milk can last for up to 10 months in your pantry [5]. 

Lima and others [3] reported that sterilized cashew milk lasted for 2 months under refrigeration. The shorter shelf life in this study compared to commercial milk is probably due to the lack of an aseptic package.   

After opening, cashew milk should be stored in the refrigerator and last 5-10 days depending on the brand [5]. For precise periods, stick to the recommendation described on the label. 

After opening, the cashew milk enters into contact with air and external contamination. Thus, it is no longer sterile, and spoilage (e.g. due to fat oxidation and microbes) will take place over time.

Homemade cashew milk should be stored in the refrigerator and last for 3-5 days. 

In both cases, chilling reduces the rate of growth of microorganisms and chemical reactions, therefore, delaying spoilage [6].

How to know your cashew milk has gone bad?

To know whether your cashew milk has gone bad, observe its appearance and feel its smell. 

Any color or viscosity change in your milk may indicate spoilage by microbial growth. Off-odors and off-flavors are other manifestations of spoilage. 

Due to the characteristics of cashew milk (pH close to neutrality), microbial spoilage of cashew milk is mainly due to bacteria, but molds and yeast may also participate.

While developing in food, these microorganisms release enzymes that break cashew milk components, promoting texture change, as well as metabolites that can produce color modifications, unpleasant odors, and flavors [6].

If you notice any of these external signs, simply discard the cashew milk. Tasting is not a good idea, because bad appearance and smell already indicate complete taste deterioration.

In addition to microbial spoilage, cashew milk fat can oxidize. This can be perceived by a rancid smell. It is not promptly harmful to your health, but you will probably reject it due to the unpleasant odor.

How to properly store your cashew milk?

Shelf-stable, unopened cashew milk should be stored in a dry, clean, cool place, for instance, in your pantry. It is not necessary to place it in the refrigerator before opening it unless you want to chill it before drinking.

The pack protects the product from microbial contamination and light, but not from heat or insect attacks. 

Moreover, if the carton is wet, it can be damaged, favoring contamination or even leakage of the product. Excessive heating may promote fat oxidation.

After opening, or in the case of fresh homemade cashew milk, it is strongly advisable to store it in the refrigerator. 

Upon chilling, the microorganism’s growth, and undesirable chemical (e.g. fat oxidation) and biochemical reactions (e.g. enzyme activity) are delayed, keeping the quality of cashew milk longer [6]. 

Never store freshly homemade cashew milk at room temperature. 

Due to its favorable characteristics, at room temperature, microorganisms multiply fast and cashew milk spoils quickly. Moreover, this can expose you to the risk of foodborne illnesses. 

 Conclusion

In this brief study, we answered the question, “Can cashew milk go bad?” Additionally, we addressed the shelf life and storage characteristics of cashew milk.

Citations

1. Tamuno ENJ, Monday  AO. Physicochemical, Mineral and Sensory Characteristics of Cashew Nut Milk. Int J of Food Sci and Biotech. 2019;4(1):1-6.

2. Silva ARA, Silva MMN, Ribeiro BD. Health issues and technological aspects of plant-based alternative milk. Food Research International. 2020;131:108972.

3. Lima JR, Bruno LM, Wurlitzer NJ, Sousa PHM de, Holanda SA de M. Cashew nut-based beverage: development, characteristics and stability during refrigerated storage. Food Sci Technol [Internet]. 2021Jun;41(Food Sci. Technol, 2021 41 suppl 1):60–4.

4. Vieira SA, Zhang G, Decker EA. Biological Implications of Lipid Oxidation Products. Journal of the American Oil Chemists’ Society. 2017;94(3):339-51.

5. https://silk.com/plant-based-products/shelf-stable/benefits-of-shelf-stable/

6. Fellows PJ. Food Processing Technology Principles and Practice. Fourth ed, 2017.