How to Make Homemade Penicillin – (Just in Case SHTF)

How to Make Penicillin at Home

Did you know that your rotting kitchen foods such as moldy bread or rotting orange can help you make one of the survival drugs called Penicillin?

According to the Action on Antibiotic Resistance, the medication Penicillin can help a person increase his or her chance of survival by up to 90%.

In this article, you will learn the step-by-step process of how to make Penicillin in the comfort of your home.

How Did They Make Penicillin?


What is Penicillin and How Does it Work?

Penicillin, with a chemical name C16H18N2O5S, is an antibiotic that belongs to the chemical compounds Beta-lactams.

The discoverer behind this drug is the Scottish Physician named Alexander Fleming.

It was discovered in the year 1928 and did you know that in 2019, it was reported that around 2.1 million individuals in the United States use these antibiotics.

Take note that there are many penicillin antibiotics. Some of these include:

  • Amoxicillin
  • Ampicillin
  • Dicloxacillin
  • Nafcillin
  • Oxacillin
  • Penicillin G
  • Penicillin V
  • Piperacillin
  • Ticarcillin

Generally, Penicillin antibiotics end with the letters “-cillin” and they are obtained from Penicillium molds such as Penicillium chrysogenum and Penicillium rubens.

Drug Uses

Soap and water can help a person prevent most infections and bacteria.

However, when infections enter the human body, everything will start to get worse.

Just imagine, you are on a vacation and suddenly got wounds or cuts that lead to infection. How would you handle it without any medication?

Take a look at the indications of Penicillin:

  • Pneumonia
  • Anthrax
  • Diphtheria
  • Tuberculosis
  • Syphilis
  • Meningitis
  • Abscesses
  • Leptospirosis
  • Lyme disease
  • Scarlet and typhoid fever
  • Ear, nose, and strep throat infections
  • Skin diseases
  • Mouth and gum issues

With all of these uses, wouldn’t it be nice to learn how to make one especially during an apocalyptic event?

The Drug Preparation: Materials Needed

For you to have a smooth and easy DIY Penicillin antibiotic preparation, you have to make sure that you have the complete set of materials.

In this section, you will learn the materials and utensils you will need in how to make Penicillin at home.

Penicillium Mold Isolation

  • Molded food or food to mold (cantaloupe, citrus rind, or bread mold)
  • Sterilized large deep glass container
  • Saran wrap
  • Distilled water with a temperature of 15°-25°C

Penicillium Mold Culturing

  • 200 g of unpeeled potato (should be washed)
  • Mason jar with metal lid
  • Large pot 
  • Cheesecloth (new or sterilized) or coffee filter
  • Strainer (sterilized)
  • 1 liter sterilized glass beaker and metal spoon
  • 20 g sugar or agar (plain unflavored gelatin can be an alternative)
  • 2 liters of distilled water

Mold Transfer

  • Hard metal, thin piece of wire with an oval loop end
  • Bunsen burner or candle for flame


There are many ingredients, such as sodium nitrate, lactose monohydrate, glucose monohydrate, magnesium sulfate, manganese sulfate, and potassium monophosphate, which can be used during the fermentation process.

However, these raw materials are hard to find during an apocalypse!

  • Sterilized mason jar (or Erlenmeyer flask)
  • Sterilized metal spoon or metal stirrer
  • 100 mL graduated cylinder
  • 1 teaspoon of sugar
  • 1 teaspoon of yeast extract
  • 1 teaspoon of citric acid
  • 1 teaspoon of nonfat milk powder
  • 1 teaspoon of sea salt
  • Sterilized aluminum foil


  • Metal strainer (sterilized)
  • Cheesecloth (new or sterilized)
  • Sterilized glass beaker 
  • Sterilized metal spoon or metal stirrer
  • pH tester
  • HCl and dropper
  • Separator funnel
  • Ethyl acetate
  • Potassium acetate

The Antibiotic Drug Manufacture: Step-by-Step Process in Making Penicillin

Now that you have all the necessary materials and utensils, it is about time for you to produce Penicillin, one of the best antibiotics that have been discovered!

Again, take note that all of the utensils should be sterilized.

Step 1: Isolating the Penicillium Mold

If you have molds already, you can skip this step. If you have none yet, follow the easy steps below:

  • Clean your hands with soap and water
  • Take your chosen food 
  • If you will be using a cantaloupe, wash it with a clean cloth
  • If you will be using bread of a citrus rind, place it inside a sterilized large deep glass container
  • Cover the food with a saran wrap
  • To prevent the food from drying out, leave an inch uncovered
  • Set aside the container and keep it in a dark place
  • Keep away from direct sunlight
  • Keep the container at room temperature 
  • Wait for the molds to grow
  • The initial color is gray mold that will eventually turns bluish-green
  • The best color is bluish-green mold
  • For a few weeks, this bluish-green mold develops

Step 2: Preparing the Growth Media: Penicillium Culture

In this step, you will have to grow the molds using a potato and sugar broth. To understand more, follow the steps below:

  • Slice the 200g of washed, unpeeled potatoes
  • Transfer the sliced potatoes into the mason jar
  • Fill the jar with distilled water with the lid tightly closed
  • In a large pot, boil some water and submerge the entire jar
  • Continue boiling water for 30 minutes
  • Once the mason jar is cooled, pour the broth into a sterilized beaker
  • When pouring, run the broth in a sterilized cheesecloth and strainer
  • Add 20 grams of sugar/agar/gelatin and mix thoroughly 
  • Always use a sterilized metal spoon or stirrer
  • Add enough cold tap water or distilled water to make the content 1 liter
  • Pour the broth in your flat mason jars
  • Make sure that these jars are sterilized
  • Each jar should contain ¾ of the broth
  • Quickly close the jars and make sure that you do not touch the inside of the jars to maintain sterility

Step 3: Transferring the Mold into the Sugar and Potato Broth 

After the step above, it is expected that the mixture is still warm. Once cooled down, transfer the mold into the mixture by following the steps below:

  • In this step, prepare the mold and growth media
  • Prepare your source of fire
  • Could be a candle or a bunsen burner
  • The loop end of the wire should be heated until it becomes red hot
  • This is one of the sterile techniques
  • Cool the wire by dipping it in one of the mason jars with broth (growth media)
  • When it is cooled down, use the loop end to touch the bluish-green part
  • Then, place the loop end beneath the surface of the broth and make two lines
  • Do this step for the rest of the broth in the other molds in the mason jars
  • Make sure that you sterilize the wire every after jar
  • Continue keeping the jars at room temperature, away from direct sunlight
  • For about a week, there will be a yellow or light-yellow substance that will be visible within the borders of the jars – and this is the PENICILLIN!
  • When there is still no yellow substance after a week, wait for a few more days
  • If there is none, discard the jar

Step 4: Fermenting the Penicillium

Fermenting the substance will increase the yield of the drug. Doing this will facilitate the growth and reproduction of the molds in the jars.

Only continue on this step when you are sure that the substance that grew in the border of the jars is penicillin.

  • Prepare the materials and make sure that they are all sterilized
  • In a 100 ml graduated cylinder, place the following:
  • 1 teaspoon of sugar
  • 1 teaspoon of yeast extract
  • 1 teaspoon of citric acid
  • 1 teaspoon of nonfat milk powder
  • 1 teaspoon of sea salt
  • Incorporate more cold water to reach the 100ml mark
  • Mix well using a sterilized metal spoon or stirrer
  • Transfer the mixture to a mason jar or Erlenmeyer flask
  • Then, transfer the growth media into the mason jar or sterilized flask
  • Make sure that the two containers will not touch one another
  • Cover the container with aluminum foil (sterilized)
  • Leave the mixture for 7-14 days
  • Do not exceed 14 days as this period might kill the Penicillium

Step 5: Extracting and Purifying the Penicillium

This is the last step in making at-home Penicillin. To know if you are successful in fermenting the Penicillin, you will see solid parts floating above the liquid mixture, called Penicillium mold colony.

This mold colony can degrade rapidly that is why turning into a powder form is necessary.

  • Chill 500 mL of ethyl acetate in the freezer for one hour (this ingredient will help you extract pure penicillin)
  • You can also place the EA in an ice bath
  • Then, prepare the following:
  • One liter beaker
  • Sterilized strainer
  • New or sterilized cheesecloth
  • Pour the fermented liquid into the beaker through the cheesecloth
  • Test the strained liquid with a pH tester such as litmus paper
  • The pH will be between 5.0 to 5.5
  • The pH which you must achieve must be between 2.0 to 2.2
  • To get this pH, use a dropper and make a few drops of hydrochloric acid
  • Every drop, stir the mixture and check the pH level
  • Once the pH is achieved, take the chilled EA
  • Prepare the separatory funnel 
  • Close the bottom lid of the funnel and pour the chilled EA, followed by the strained liquid penicillin
  • Close the top lid of the funnel and shake the mixture for 30 seconds
  • The mixture then will separate
  • Upper fluid is the strained mixture
  • The bottom liquid portion is the cold ethyl acetate where the penicillin will completely dissolve
  • Pour the bottom liquid into another beaker and drain it
  • Add potassium acetate into the drained, cold ethyl acetate
  • The ratio should be 1mL potassium acetate per 100mL drained acetate
  • Set aside the drained acetate in a well-ventilated area
  • The acetate will then evaporate, leaving the powder alone
  • Place the penicillin powder in an amber bottle and refrigerate immediately

How to Test the DIY Penicillin

If you have successfully done all the procedures above, you can also try testing your DIY penicillin to validate if the fungi growing is indeed Penicillin.

Using Petri dishes, inoculate different susceptible bacteria. Then, get some drops from your penicillin broth, and place them in each petri dish.

If there is a zone of inhibition, your DIY Penicillin, good luck because your antibiotics are truly effective! 

Tips When Using Homemade Penicillin

  • Do not use the broth as a penicillin tea or penicillin soup
  • Do not rub the molds into your wounds
  • Use the penicillin antibiotic properly

Alternatives for Penicillin

In the case of an apocalypse, there are other alternatives for the Penicillin drug. These are ready-to-use antibiotics and penicillin-ready medications.

Some of the things you can consider as alternatives include:

  • Buy fish medicine (fish pen) 
  • Buy fish antibiotics

Take note that the best way to get effective antibiotics is by seeking medical help. If you have more time, always choose this as your first option.

Final Thoughts

Antibiotic resistance is one of the challenges in the health industry today.

However, it is an advantage for preppers if they know how to make penicillin at home, especially during an apocalyptic event!

Although making the Penicillin antibiotic at home requires a lot of time and effort, it will surely be worth it.

Remember, those who know more will easily get through hard times!