Will milk go bad if left out overnight?
By
Dr Rafael Frascino Cassaro (PhD)
| Reviewed by
Dr Anny Manrich (PhD)
The contents of this article are fact-based except otherwise stated within the article.
Author bio
Dr Rafael Frascino Cassaro PhD is a Chemist with expertise in Food Technology, extraction of essential oils from food sources, organocatalysis, extraction by supercritical CO2 and organic chemistry. He writes and reviews content on these topics.
Dr Rafael Frascino Cassaro’s Highlights:
- PIPE-FAPESP Project Coordinator for the company Bioativos Naturais Ltda involving the extraction of essential oils from food sources, with supercritical CO2.
- PhD in Chemistry with research in supercritical fluid reactivity.
- Bachelor of Environmental Chemistry at University of São Paulo State (UNESP)/Brazil
Professional Experience:
Dr Rafael Frascino Cassaro’s Experience:
Dr Rafael coordinated a PIPE-FAPESP Project (Company Research and Innovation Project) for the company Bioativos Naturais Ltda, involving the extraction of essential oils with supercritical CO2 from food sources such as turmeric, ginger, hops, orange bagasse, pepper rose, cupuaçu pie, among others.
Dr Rafael has worked on a project, involving studies of the influence of pre-treatment on the recovery of crude food extracts by extraction with supercritical CO2 (Supercritical Fluid Extraction or SFE) and with pressurized liquids (ethanol and water) for food sources, aimed at obtaining oleoresins; determination of global yield and chemical composition of crude extracts. As a postdoctoral fellow for the Food Engineering department at the University of Campinas/Brazil
Dr Rafael Frascino Cassaro has worked as a substitute Professor at the University of São Paulo State (UNESP) on General Chemistry and Thermodynamics II disciplines for the Food Engineering course.
Education:
- 2009 Bachelor in Environmental Chemistry at the State University of São Paulo, Brazil
- 2015 PhD in Chemistry with research in supercritical fluid reactivity University of São Paulo, Brazil
- 2017 Post Doctoral in Food Engineering Research: Influence of Biomass Pre-Treatment on Supercritical CO2 Extraction: Preservation of High Added Value Assets and Reduction of Process Costs at the State University of Campinas, Brazil
The main publications of Dr Rafael Frascino Cassaro are:
RC Bazito, RF CASSARO, LC OLIVEIRA, RA Gariani, CAO Nascimento. (2013). Proline derivatives as organocatalysts for the aldol reaction in conventional and non-conventional reaction media. Green Processing and Synthesis 2, 43-50
TS Bastos, SB Rodriguez Reartes, MS Zabaloy, RF Cassaro, RC Bazito. (2019).Phase Behavior for the System Carbon Dioxide plus p-Nitrobenzaldehyde: Experimental and Modeling JOURNAL OF CHEMICAL AND ENGINEERING DATA 64 (5), 2116-2125
GH Sakae, LM Takata, AS Paulino, RC Bazito, RF Cassaro, C Princival, .(2013). A high enantioselective Proline-based helical polymer catalyst for aldol type reaction. Blucher Chemistry Proceedings 1 (2), 214-214
You can view some of Dr Rafael’s work below and links to his professional profile.
Research Gate: https://www.researchgate.net/profile/Rafael-Cassaro-2
Fapesp: https://bv.fapesp.br/pt/pesquisador/680718/rafael-frascino-cassaro/
Google Scholar: https://scholar.google.com/citations?user=ToO7HIcAAAAJ&hl=en
Linkedin: https://www.linkedin.com/in/rafael-frascino-cassaro-4a156a37/?originalSubdomain=br
ORCID: https://orcid.org/0000-0002-3729-2858
Reviewer bio
Dr Anny Manrich PhD is a food Engineer with expertise in Food Technology, Natural Polymers, Edible Films, Enzymes, and Nanotechnology. She writes and reviews content on these topics.
Dr Anny Manrich’s Highlights:
- Research and Technology at the Brazilian Agricultural Research Corporation
- PhD in Chemical Engineering with a focus on Biochemistry at the Federal University of Sao Carlos/ Brazil and a one-year scholarship at the Technical University of Munich/ Germany
- Bachelor of Food Engineering at the University of Campinas/ Brazil and a one-year scholarship at the Technical University of Munich/ Germany
“To solve a problem, global vision and multifactorial understanding are necessary. Therefore, in addition to expertise, one should seek multidisciplinary thinking connected with science and reality” – Dr Anny Manrich, PhD.
Professional Experience:
Dr Anny Manrich’s Experience Joining the Brazilian Agricultural Research Corporation, as soon as she completed her doctorate,
Dr Anny Manrich has worked on several projects, including the more than three-year partnership project with BRF, a major food producer in Brazil. As a postdoctoral fellow.
Dr Anny Manrich has also contributed to several business consultancies and research projects of the National Nanotechnology Laboratory System in areas such as food technology, fibres, films and coatings and Nanotechnology; in a very determined way, having a great team relationship, being creative and committed.
Growing concerns about the safe introduction of nanomaterials into today’s life emphasises the need to create regulatory documentation in front of characterising, using and testing them. Dr Anny Manrich worked for two years on a characterization project for nanoscale materials, with the aim of exploring their possible health effects.
Despite not having specific academic training in packaging or polymeric films, Dr Anny Manrich works at the Brazilian Agricultural Research Corporation in areas of edible and biodegradable films produced from agricultural waste and in the development of films with greater resistance to water, having articles published in renowned scientific journals, which demonstrates her multidisciplinary understanding and creativity.
In addition, she worked for four years as a consultant to a food company to develop a line of snacks that are healthy and that add functional ingredients, physiologically active compounds that bring health benefits, made from fruits and vegetables, enabling diet improvement, disease prevention and reduction of nutritional deficiencies.
Dr Anny Manrich participated as a member of the examination board for two Master’s exams and one PhD exam at the Department of Chemical Engineering of the Federal University of São Carlos.
Education:
- 2001 Bachelor in Food Engineering at the State University of Campinas, Brazil
- 1999 One year scholarship at the Technical University of Munich
- 2004 Master in Chemical Engineering at the Federal University of São Carlos, Brazil
- 2012 PhD in Chemical Engineering at the Federal University of São Carlos, Brazil
- 2010 One year scholarship at the Technical University of Munich
The main publications of Dr. Anny Manrich are:
Articles
Manrich, A., Moreira, F. K., Otoni, C. G., Lorevice, M. V., Martins, M. A., & Mattoso, L. H. (2017). Hydrophobic edible films made up of tomato cutin and pectin. Carbohydrate Polymers, 164, 83-91.
Mendes, J. F., Norcino, L. B., Martins, H. H. A., Manrich, A., Otoni, C. G., Carvalho, E. E. N., … & Mattoso, L. H. C. (2020). Correlating emulsion characteristics with the properties of active starch films loaded with lemongrass essential oil. Food Hydrocolloids, 100, 105428.
Norcino, L. B., Mendes, J. F., Natarelli, C. V. L., Manrich, A., Oliveira, J. E., & Mattoso, L. H. C. (2020). Pectin films loaded with copaiba oil nanoemulsions for potential use as bio-based active packaging. Food Hydrocolloids, 106, 105862.
Manrich, Anny, et al. Immobilization of trypsin on chitosan gels: Use of different activation protocols and comparison with other supports. International Journal of Biological Macromolecules 43.1 (2008): 54-61.
Manrich, Anny; Komesu, Andrea ; Adriano, Wellington Sabino; Tardioli, Paulo Waldir ; Giordano, Raquel Lima Camargo . Immobilization and Stabilization of Xylanase by Multipoint Covalent Attachment on Agarose and on Chitosan Supports. Applied Biochemistry and Biotechnology, v. 161, p. 455-467, 2010.
Mendes, J. F., Martins, J. T., Manrich, A., Neto, A. S., Pinheiro, A. C. M., Mattoso, L. H. C., & Martins, M. A. (2019). Development and physical-chemical properties of pectin film reinforced with spent coffee grounds by continuous casting. Carbohydrate polymers, 210, 92-99..
Milessi, T. S., Kopp, W., Rojas, M. J., Manrich, A., Baptista-Neto, A., Tardioli, P. W., … & Giordano, R. L. (2016). Immobilization and stabilization of an endoxylanase from Bacillus subtilis (XynA) for xylooligosaccharides (XOs) production. Catalysis Today, 259, 130-139.
Mendes, J. F., Norcino, L. B., Manrich, A., Pinheiro, A. C. M., Oliveira, J. E., & Mattoso, L. H. C. (2020). Development, physical‐chemical properties, and photodegradation of pectin film reinforced with malt bagasse fibers by continuous casting. Journal of Applied Polymer Science, 137(39), 49178.
Mendes, J. F., Martins, J. T., Manrich, A., Luchesi, B. R., Dantas, A. P. S., Vanderlei, R. M., … & Martins, M. A. (2021). Thermo-physical and mechanical characteristics of composites based on high-density polyethylene (HDPE) e spent coffee grounds (SCG). Journal of Polymers and the Environment, 29, 2888-2900..
Mendes, J. F., Norcino, L. B., Martins, H. H., Manrich, A., Otoni, C. G., Carvalho, E. E. N., … & Mattoso, L. H. C. (2021). Development of quaternary nanocomposites made up of cassava starch, cocoa butter, lemongrass essential oil nanoemulsion, and brewery spent grain fibers. Journal of Food Science, 86(5), 1979-1996.
Manrich, A., Martins, M. A., & Mattoso, L. H. C. (2021). Manufacture and performance of peanut skin cellulose nanocrystals. Scientia Agricola, 79.
Nascimento, V. M., Manrich, A., Tardioli, P. W., de Campos Giordano, R., de Moraes Rocha, G. J., & Giordano, R. D. L. C. (2016). Alkaline pretreatment for practicable production of ethanol and xylooligosaccharides. Bioethanol, 2(1)..
Manrich, Anny, de Oliveira, J. E., Martins, M. A., & Mattoso, L. H. C. Physicochemical and Thermal Characterization of the Spirulina platensis. J. Agric. Sci. Technol. B, v. 10, p. 298-307, 2020.
Book Chapter
Terra, I. A. A., Aoki, P. H., Delezuk, J. A. D. M., Martins, M. A., Manrich, A., Silva, M. J., … & Miranda, P. B. (2022). Técnicas de Caracterização de Polímeros. Nanotecnologia Aplicada a Polímeros, 614.
Conference Papers
Ferreira, L. F., Luvizaro, L. B., Manrich, A., Martins, M. A., Júnior, M. G., & Dias, M. V. (2017). Comparação da estabilidade de suspensões poliméricas de amido/tocoferol e quitosana/tocoferol. In: CONGRESSO BRASILEIRO DE POLÍMEROS, 14., 2017, Águas de Lindóia, SP.
Manrich, A., Hubinger, S. Z., & Paris, E. C. (2017). Citotoxicidade causada por nanomateriais: avaliação do micronúcleo. In: WORKSHOP DA REDE DE NANOTECNOLOGIA APLICADA AO AGRONEGÓCIO, 9., 2017, São Carlos. Anais… São Carlos: Embrapa Instrumentação, 2017. p. 655-658.
Manrich, Anny, et al. Immobilization and Stabilization of Xylanase by multipoint covalent attachment on Glyoxyl Agarose Support. The 31st Symposium on Biotechnology for Fuels and Chemicals. 2009.
Manrich, Anny, et al. Application of immobilized xylanase on hydrolysis of soluble wood hemicelluloses after using microwave and organosolv pre-treatments. The 32nd Symposium on Biotechnology for Fuels and Chemicals. 2010.
You can view some of Dr Anny’s work below and links to her professional profile.
Research Gate: https://www.researchgate.net/profile/Anny-Manrich-2
Scopus: https://www.scopus.com/authid/detail.uri?authorId=23103497100
Google Scholar: https://scholar.google.com/citations?hl=en&user=Ea9qpr0AAAAJ
Linkedin: https://br.linkedin.com/in/anny-manrich-20693129
In this brief guide, we will answer the question,’ Will Milk go bad if left out overnight?’ We will discuss the factors that make milk a perishable food and the appearance of signs that indicate spoilage.
Will milk go bad if left out overnight?
Yes, open milk lasts for about 2 hours before getting spoiled when left out at room temperature.
You should discard the milk that has been left in the open for more than 2 hours as bacterial growth takes place at a faster pace between the temperature of 40 and 140 degrees Fahrenheit.
Open milk, whether it be whole milk, skim milk, or reduced-fat milk, stays for about 4 to 7 days before getting spoiled when stored in the fridge at or below 40 degrees Fahrenheit in an air-tight container or bottle.
On the other hand, the unopened whole milk lasts for about 5-7 days, reduced-fat and skim milk for 7 days while non-fat and lactose-free milk for 7-10 days past the printed date on it provided that it is stored properly in the fridge at or below 40 degrees Fahrenheit. (1-3)
How to store milk?
When it comes to storing pasteurized milk, it is recommended to keep it in the refrigerator at a temperature range of 3-4°C (38-40°F). Placing the milk carton in the refrigerator door should be avoided to minimize temperature fluctuations that can affect its quality.
If you wish to extend the shelf life of milk, freezing is an option. Frozen milk can remain safe for consumption for up to 6 months.
However, for the best quality, it is advisable to consume frozen milk within a month. It’s worth noting that freezing may cause a slight grainy texture and fat separation in the milk. Therefore, frozen milk is better suited for cooking purposes or as an ingredient in smoothies and shakes.
To ensure proper storage, it is crucial to maintain the temperature of your refrigerator between 3-4°C (38-40°F). After using milk, promptly returning the carton to the refrigerator helps maintain its freshness and prevents potential spoilage. (4)
What factors affect milk shelf life?
The shelf life of milk is heavily influenced by storage temperatures and methods.
Inadequate handling practices, improper storage temperatures, and insufficient storage durations can create opportunities for pathogenic microorganisms to enter, posing significant risks to public health.
In tropical regions where chilling facilities may be lacking during transportation, storage, or retail, bacteria cells can recover and proliferate due to favorable temperatures.
Consequently, there is an increased risk of recontamination of processed milk even after heat treatment, primarily resulting from poor hygiene practices.
To mitigate these risks, it is crucial to implement proper temperature control and adopt suitable storage practices. By doing so, the growth of bacteria can be minimized, effectively extending the shelf life of milk and ensuring its safety for consumption. (5)
How does milk spoil?
Milk is home to bacteria such as lactococci and lactobacilli. At temperatures above room temperature, they breed and reproduce. The probiotic bacteria change the lactose milk sugar into its compositional units; glucose and galactose.
The formation of lactic acid starts, as proved by the familiar tangy smell and taste. As the casein develops, the curdling process starts.
As milk deteriorates further, the bacteria take over the fats, which causes the occurrence of molds.
Spoilt raw milk may become inedible as it curdles and gains its distinct sour taste and odor. However, it does not need to be discarded, as curdled milk is used to make cheese, cream, and kefir.
On the other hand, pasteurized milk does not become sour due to the absence of bacteria that cause the milk to curdle. Instead, it rots and becomes unfit for consumption. (6)
How to tell if that milk has gone bad?
As milk spoils, you can detect a rancid and sour smell.
The texture and consistency change too, and the color becomes pale with a yellowish tinge.
Other characteristics such as an “acidic aftertaste,” “chalky mouthfeel,” or “sourness” can serve as specific examples of milk spoilage. (6)
What happens if you drink spoiled milk?
If you drink milk that was left out overnight, you risk falling sick. Even if it smells and looks fine, it must be tossed out.
Spoiled Milk can cause food poisoning with symptoms such as vomiting and diarrhea.
It’s important to note that milk spoilage is caused by a wide range of microorganisms, but certain bacteria can pose significant health risks to consumers.
Fortunately, in most cases, these symptoms should significantly improve or disappear within three days.
However, if the symptoms persist and worsen or if you have any concerns, it is advisable to seek medical attention and consult with a doctor. (6, 7)
Conclusion
In this brief guide, we answered the question,’ Will milk go bad if left out overnight?’ We discussed the factors that make the milk a perishable food and the appearance of signs that indicate spoilage.
Other FAQs about Milk which you may be interested in.
How long does breast milk last outside the fridge?
Citations
- U.S. Department of Agriculture. https://ask.usda.gov/ Website. Washington, DC. What is the “2 Hour Rule” with leaving food out?.
- Buehler, A. J., Martin, N. H., Boor, K. J., & Wiedmann, M. Psychrotolerant spore-former growth characterization for the development of a dairy spoilage predictive model. Journal of Dairy Science, 101(8), 6964–6981. 2018.
- Lacroix, M., Bon, C., Bos, C., Léonil, J., Benamouzig, R., Luengo, C., … Gaudichon, C. Ultra High Temperature Treatment, but Not Pasteurization, Affects the Postprandial Kinetics of Milk Proteins in Humans. The Journal of Nutrition, 138(12), 2342–2347. 2008.
- Adda Bjarnadottir, Kelli McGrane, How Long Is Milk Good for After the Expiration Date? Them. Healthline Media LLC. 2020
- Dortey, M. D., Aboagye, G., & Tuah, B. Effect of storage methods and duration of storage on the bacteriological quality of processed liquid milk post-opening. Scientific African, 10, e00555. 2020.
- Lu, M., & Wang, N. S. Spoilage of Milk and Dairy Products. The Microbiological Quality of Food, 151–178. 2017.
- Adda Bjarnadottir, Kelli McGrane, How Long Is Milk Good for After the Expiration Date? Them. Healthline Media LLC. 2020
