The optimal environment for bacterial growth on any food item is warm and moist. If a food item, such as lemon juice, is left out in temperatures between 40 and 140 degrees Fahrenheit, it is considered to be in the “danger zone” for bacterial growth. Citric acid in lemon juice acts as a natural preservative and will prevent the bacteria from growing as quickly, but it can start to grow if left out long enough. Once the bacterial has established a rapid growth pattern, it is dangerous to consume. Contaminated lemon juice can possibly lead to food poisoning or illness.


Indicators

Changes in the color or flavor of your lemon juice can indicate that it has gone bad. If the lemon juice tastes flat without the normal citrus tanginess or has a cloudy or darker yellow color, do not consume it. These changes will occur more quickly with freshly squeezed lemon juice if left unrefrigerated as there are no additional preservatives to keep it fresh. Fresh lemon juice only has a shelf life of two to four days, even if it is refrigerated. You can freeze unused freshly squeezed lemon juice to avoid spoiling. The average shelf life expectancy for opened and refrigerated bottled lemon juice is around six months. Unopened bottles do not need to be refrigerated and can last up to 15 months. Always check the expiration date on the bottle and the appearance of the liquid before you consume it.

Cross Contaimination

Once bacteria have established their growing and multiplying pattern, mold patches can form in your unrefrigerated lemon juice. This not only is dangerous to consume, but the mold spores can spread to other food items in your kitchen and contaminate them as well. If you notice mold in your lemon juice, go to the sink and dump the liquid out of the bottle or container immediately. Rinse the bottle out thoroughly and recycle it. Getting rid of bacteria ridden and moldy items will help to prevent further spread of mold spores, thus helping to cut down on other possible illness-inducing factors.

Diarrhea

Diarrhea is one of the most frequent indicators that you have ingested bad food items or have food poisoning. This is the body’s natural defense system to get rid of undesirable food items. Diarrhea may occur if your lemon juice had bacterial growth from being in the “danger zone” too long. Make sure to drink plenty of water if this occurs to prevent dehydration. It is also a good idea to stay away from solid foods until the symptoms go away, especially dairy products, sugary foods, meat and alcohol.

Abdominal Pain

Abdominal pain is a possible indicator of food poisoning. This could simply be caused by normal stomach acids or gas, or it can be a sign that you have consumed a contaminated food item, such as unrefrigerated lemon juice. Abdominal pain may be accompanied by other symptoms, such as vomiting and diarrhea.

Vomiting

You may experience vomiting or nausea if you have eaten food that has spoiled or contaminated with bacteria or viruses. This is also a natural defense mechanism that your body has to get unwanted invaders out of the body by any means necessary. If this is the case, do not try to stop vomiting. You want the contaminated food out of your body.

Changes in Body Temperature

You may experience fever or chills as a sign of food poisoning from contaminated lemon juice. You may also experience cold sweats during this period. Fever is an indicator that your immune system is going into overdrive to try to combat an unwanted invader. The fever is a natural result from this as the body tries to burn off the substance.