Cold Brew Coffee should last you for around two weeks once it’s stored in the fridge using an airtight container.
Why Does Cold Brew Coffee Go Bad
There are two main factors that cause your cold brew to spoil:
1-Oxidation / Interaction With Air
Oxidation is the process whereby a compound bonds with oxygen,
This process permanently changes the chemical makeup of the substance.
A good example of natural oxidation is when you cut an apple how it quickly changes from white to brown.
Now when the compounds in coffee are allowed to bond with oxygen in the air it slowly oxidizes which degrades the coffee’s taste over time.
2-Microbes or Bacteria
Microbes and bacteria produce toxins which contaminate and spoil your cold brew over time.
Microbes just need water, air, and food to survive and thrive.
Cold Brew Coffee has all of these elements so over time bacteria and mold would start to multiply inside your brew.
Dont worry I have 5 tips to help you fight against bacteria and oxidation without hurting the taste so keep on reading.
5 Tips To Make Your Cold Brew Coffee Last Longer
1- Make a Cold Brew Concentrate
A Cold Brew Concentrate is a very concentrated coffee syrup.
Now by making and storing your cold brew as a concentrate, you reduce the overall water content.
This makes your brew last longer because it reduces the amount of bacteria content.
You see bacteria need a good supply of water to grow and by having less water, slows down the growth rate of these microbes.
How to Make a Concentrate
A Concentrate is made by using 1 part coffee to 2 parts of water.
The Syrup is then stored away until needed.
Now when you are ready for your cold brew, water is then added to the concentrated syrup until
2- Use an Air Tight Container
If you store your cold brew inside an airtight container this would significantly increase how long your cold brew should last for.
This is because of two reasons;
- The lack of Oxygen slows down the oxidation of the coffee’s compounds.
- And helps to starve microbes that need oxygen to live.
An airtight container refers to a container that is sealed so as to not allow air to flow freely.
A simple mason jar should suffice or for larger quantities ensure the container is tightly corked.
Also, avoid constantly opening the container containing the cold brew this allows more air to flow into the coffee.
Now if you want your cold brew to last longer think roughly 3 weeks or more you can use a vacuum to suck the air out from inside the container which would dramatically increase how long your cold brew coffee would last.
By vacuuming out all the air won’t make the brew last forever, oxidation would still happen, this is because the water itself has oxygen which would oxidize the compounds in the coffee, it would buy you more time.
For this, you would need, see below for the items you would need you can click to see the price of each item on Amazon;
Just remember to vacuum out the air every time you open your lid since every time you open more air will enter. You can see how it is done in the video below.
3- Store Your Cold Brew in The Fridge
By storing your cold brew in the fridge would slow down the rate of metabolism of the microbes inside your cold brew thus decreasing their multiplication and production of toxins.
The colder the better, just avoid freezing your cold brew, what freezing does is that it separates the water from the coffee and gives it a watery taste.
4- Avoid Adding Any Additives to Your Cold Brew
When storing your cold brew for a long period of time avoiding adding any additives such as sugar, spices or milk.
These additives work as food for the bacteria which speed up the rate of spoilage of your cold brew.
5- Know Your Limit
Only make the amount of cold brew that you estimate that you would use keep in mind the two-week rule and you should be fine.
If you know you are gonna drink 2 liters of cold brew within two weeks just make 2 liters of cold brew.
How Do You know When Your Cold Brew Coffee Has Gone Bad
The main way you can tell if your cold brew has spoiled is by tasting it, now if it has spoiled it would have an unusually harsh taste, also if even time has passed it might even develop a putrid scent.
Now after one week even if your cold brew is stored in the fridge using an airtight container its still gonna start to slowly lose its taste.
How Cold Brew Coffee is Preserved for Extra Long Period in Cans
There are two main things that are added to cold brew to preserve it in the can, they are:
- Preservatives these are chemicals that are added to preserve the cold brew usually by killing the microbes, usually, they alter the taste of the brew and are usually used for commercial purposes only
- Nitrogen Gas is dissolved in the cold brew coffee when they are stored in the cans, nitrogen helps to slow down the oxidation of the coffee and preserves the taste.