Whether its microbial or pathogen you need to know what this all means to the safety of your cold brew.
The sources of microbial contamination can be your water, the containers you are using, your equipment that you’re brewing in, the environment and even your personnel.
The growth of the bacteria and the formation of toxins occur with low oxygen content and certain combinations of storage temperatures. Given that most cold brew has no preservatives, there is always a risk.
Non-pathogens like yeast and mould can taste unpalatable which you will reject when you taste it.
But pathogens like salmonella, E. coli, listeria are tasteless and can cause you harm, which is dangerous and can be disastrous to your customer and the coffee industry in general.
To counter these potential problems, you need to look at your “good manufacturing practices” (GMP).
Including:
Cleaning and sanitation program which means that all your processing & packaging of the cold brew is aseptic.
Your cold brew PH levels are below <4.6
You get each batch of product tested by a scientific lab to monitor all your levels.
As for shelf life, I wouldn’t recommend keeping cold brew for longer than 3-5 days in the refrigerator. As a cold brew concentrate, you could keep this for slightly longer, maybe 7-12 days in the refrigerator. But be careful.
Using the refrigeration method will control the activation of germinating spores (Release of toxins during growth. Toxins causing food poisoning).
But the rule of thumb if you aren’t using preservatives or a pasteurisation method, don’t leave your cold brew at room temperature unless you want to find mould or yeast lying on top of your product.
I don’t want to scare people about the risks involved, even though it is low, we all need to be aware of what we are creating and what possible consequences there are when handling cold brew. As we have a responsibility to the people we serve.
About the Author
Justin Metcalf is one of the most recognised coffee & café consultants. His companies, Luxe Brew Australia & Singapore supply’s all types of roast and ground coffee, including newly developed coffee alcohol products such as espresso martini and coffee liqueur
