Does Lemon Juice Kill Mold? Yes, And Here’s How To Use It

Removing mold in the home can be a tricky task, often, harsh chemical sprays and solutions are suggested in order to kill it for good, but what if you’d rather not use these methods? Are there more natural and safer methods that you can use to not only remove mold but prevent it from recurring or even appearing in the first place?

Well, the good news is that there certainly is, lemon juice is an excellent killer of mold and mildew, and in this article, we will be explaining why it’s so effective, how to kill fungi with it, and how you can use it to stop mold from returning.

So, for all you need to know about how to kill mold using lemon juice, keep reading:

does lemon juice kill mould?

How does lemon juice kill mold?

Lemon juice has a pH of between 2-3, making it only slightly less acidic than vinegar (another popular natural method of removing mold and mildew).

The acid in the juice is powerful enough to break down the cell walls of the fungi, killing them and helping to lift the stains that they leave.

However, while the acidic juice can kill mold, due to the fact that its pH is lower than most commercial mold cleaners, the amount of time required for it to have the desired effect will be considerably longer.

Does lemon juice kill black mold?

Yes, lemon juice will kill black mold just like it would any other strain it is applied to.

Black mold (Stachybotrys chartarum), has the same makeup as many other commonly found strains growing within a property. The only difference between this strain and others is that it is more likely to produce mycotoxins that can cause potentially serious breathing problems and other allergic reactions. The actual makeup of the fungi is the same and is just as susceptible to the acidity of the lemon juice.

It must be noted, however, that the stains caused by black mold can be very difficult to lift, and the use of lemon juice to try to remove these may be insufficient. It will almost certainly kill the mold as long as it is applied for long enough, however.

How long does it take for lemon juice to kill mold?

Due to its relatively low pH level, the juice of a lemon will take significantly longer to kill mold than other natural options such as vinegar, however, it is still effective.

In order for the juice to have enough time to effectively break down the cell walls of the mold or mildew, you should apply and leave it for a minimum of 1-2 hours before attempting to clean away the mold and any residue.

As a comparison, white vinegar takes only an hour before you can begin to wipe the area clean.

Bear in mind that lemon juice kills fungi most effectively on flat non-porous surfaces, so should you be dealing with a textured tile or another surface, it may take several attempts for citrus juice to be effective.

Can lemon juice prevent mold growth?

Yes, the juice is an excellent method of reducing the likelihood of a fungal infestation due to its ability to create an inhospitable environment.

Cleaning surfaces such as window sills, bathroom enclosures, and ceilings with non-diluted citrus juice creates a barrier against the surface which the fungus will not be able to live on.

There are exceptions to this rule, as there are certain strains of mold that are able to withstand more harsh environments, so lemon juice may not prevent the growth of all strains, but it will certainly help to reduce the majority.

How to kill mold with lemon juice

Using citrus to remove mildew and fungus buildup is a simple process, and you have two equally effective methods to choose from. We will delve into each option now, and you can choose whichever you think is most practical for your circumstances. As a general rule, if mold is well established, the paste method may be more effective at lifting stains, whereas, for recently discovered mold on flat surfaces, the spray method will be adequate.

Spray method

Step 1. Pour 1 cup of undiluted fresh lemon juice (or from concentrate), into a spray bottle and liberally spray over the affected area.

Step 2. Leave the solution to work on the mold for a minimum of 1-2 hours in order to give it sufficient time to break down the cell walls of the fungi.

Step 3. Using a soft-bristled brush, apply more lemon solution and gently scrub the area in circular motions until the mold and any residue have been removed. You can then wipe the area with a clean cloth to remove any debris.

You will not need to wash the area again, as the citrus juice will leave a pleasant aroma, and can effectively combat any musty odor associated with mold.

Paste method

You can create a citrus juice paste to tackle stubborn stains and established mold by mixing lemon juice and cream of tartare (a high-acidity powder leftover from winemaking).

Step 1. Mix the juice with a teaspoon of the powder to create a thick paste and apply liberally to the affected area.

The high acidity of both the lemon and cream of tartare will effectively kill the mold, whilst the powder acts as a natural bleaching agent, helping to remove stains.

Step 2. Once applied, leave to fully dry. Depending on the temperature of the room it is applied in, this may take from 1 hour to several.

Step 3. When it is dry, use a clean cloth to wipe away the dried powder and remove any mold residue.

A word of caution

Before using any product on tiles or ceramics, check with the manufacturer for details on recommended cleaning products. Despite lemon juice’s low acidity, some materials can be delicate and may become stained or damaged even with very pH-cleaning products.

If you are unsure of how the material you are aiming to clean will react, discuss it with the manufacturer or find a very small patch of the tile or surface that cannot easily be seen. Put a small amount of diluted juice on the surface and wait for half an hour to see if there are any visible marks.

Repeat this process once more with undiluted juice to determine if it is safe to use in larger and more visible areas.


Citrus juice is an effective, environmentally friendly way to both kill and prevent mold growth in a property. Undiluted juice should be applied to the area either via a spray bottle or mixed into a paste with cream of tartare and left for 1-2 hours or until dry, then wiped clean.

The juice will not be powerful enough to kill all strains of mold and mildew, but with enough time, it will certainly assist in killing many strains and help to lift the stains caused by them.

Chris Walker

Chris Walker has struggled for several years with mold after buying his own property. After finding the solutions to several issues around his home, he decided to create this site in order to answer as many questions about mold and mildew as possible to help others dealing with the same problems.

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