It is undeniable. Cold brew has become an integral part of the specialty coffee sector. According to experts, the cold brew market will reach sales of one billion US dollars by 2025. That means an increase of a good 25 percent annually. This inevitably leads - especially in Germany, which has a lot of regulations - to the question of how safe cold brewed coffee is. The Karlsruhe Chemical and Veterinary Investigation Office, CVUA for short, examined almost 25 cold brews for possible contamination in the summer of 2020. The result was fine, as only two samples showed abnormalities. The CVUA says that hot brewed coffee is safe in terms of microbial safety. However, due to the way it is produced, cold brew offers good growth conditions for pathogens and various pathogenic germs.

Cold Brew Hygiene – Facts from around the world

Due to the rapid growth in popularity, the Cold

Brew is unfortunately not without its teething issues: Most of these are in the area of ​​food hygiene. For example, in the summer of 2022, the US Food and Drug Administration recalled 53 different drinks due to microbial contamination. This included some ready-to-drink cold brews from well-known companies such as Intelligentsia and Stumptown. Even if these cases are very rare - the CVUA also confirmed this in a series of samples - microbial contamination in cold brews does occur from time to time and must be taken into account by consumers, but above all by manufacturers. Regardless of whether you produce a few or a few thousand bottles.

Cold Brew Hygiene Standards

Since cold brew is relatively new, there are still no generally accepted standards for its production. It is usually understood to mean an extraction of ground roasted coffee with water at a low temperature for several hours. The water is usually 8 degrees Celsius (i.e. refrigerator) or room temperature. The extraction time is often twelve hours or more. The challenge in producing cold brew coffee is to adapt the extraction process to the variable properties of the coffee. The processing state of the coffee beans, such as the degree of roasting and grinding, influences the extraction behavior. The amount of coffee used, the temperature and hardness of the water, and the extraction method and duration also influence the quality and taste of the cold brew.

Cold Brew Hygiene – Increasingly popular

One of the reasons why cold brew is becoming more and more popular is that the specialty coffee culture is constantly growing and people are looking for new taste experiences. This is where the aromatic, complex cold brew comes into its own. It is also extremely simple: you just have to open the fridge, take out a ready-made can or bottle and pour the contents over ice. The cold brew is ready. With a shelf life of usually 12 months and the now wide availability in online shops , it has become even easier for consumers to enjoy cold brew. You can also find delicious cold brews in our shop .

Cold Brew Hygiene – Different ways of producing cold brew

There are probably as many cold brew recipes as there are roasters. For example, there is this one: take 100 to 150 grams of coffee powder per liter of water and let it brew in the fridge for a good 12 hours. We at 25GRAMS use, as the name suggests, 25 grams per 200-milliliter bottle and the BLVK recommends 80 grams of coffee per liter of water. These two components are then placed in a plastic or glass container - depending on the production size - and extracted at room temperature or less for up to 24 or 48 hours. But there are also very modern devices that can be used to make cold brew. The Hario Cold Brew Maker, for example, or the machines we use. While cafes often produce smaller quantities and therefore use non-automated processes , larger manufacturers should invest in efficient and hygienically safe systems. Refrigerated stainless steel containers and brewers of commercial quality should be used.

Cold Brew Hygiene – Requirements

In its examination of several cold brews, the CVUA fortunately discovered a few samples with microbial contamination , but enough to postulate hygienic requirements for the production of cold brew. Coffee is exposed to many microbial risks during processing, writes the CVUA on its website . "The warm, humid and tropical climatic conditions during coffee cultivation provide an ideal environment for the growth of various types of fungi. Errors in processing and storage can lead to further contamination. Enterobacteriaceae play a particularly important role here," it continues. The fact that green coffee is roasted and brewed at high temperatures and is usually consumed in this state means that any microbial contamination can be neglected. This is not the case with cold brew. For example , no heating process takes place during the production of cold brew coffee, and therefore no killing of any microorganisms that may be present.

Cold Brew Hygiene – Environment and Dangers

Cold brew is not heated and cold brew extracts for much longer than hot coffee. This alone gives microorganisms the opportunity to spread. In addition, cold brew usually only has a slightly acidic environment (pH value between 4.9 and 6.0). This does not inhibit microbial growth. This means that yeasts, molds and lactic and acetic acid-forming bacteria can multiply during the extraction process, which lasts several hours, and the subsequent storage. Other dangers for cold brew are salmonella and listeria. In order to prevent cold brew from becoming contaminated, any sources of contamination must be identified and eliminated. The main thing here is to keep the staff, ingredients and equipment used clean at all times. The CVUA recommends: "Accordingly, cold brew coffee must be given special consideration in the manufacturer's HACCP (Hazard Analysis Critical Control Point) concept and if there are any abnormalities, a step-by-step check is recommended."

Cold Brew Hygiene – Tips and tricks

When making cold brew - both at home for private individuals and in coffee shops - the rule is that the brew should be made fresh and ideally used up on the same day. "Long storage (several days to weeks) of cold brew coffee leads to an increased risk of microbial contamination and also affects the taste (also through chemical processes such as oxidation)," describes the CVUA. Nevertheless, the cold brew from 25GRAMS has a shelf life of 14 months (because it is pasteurized) if stored correctly. So store it in a cool, dark place; once opened, it will of course only last a few days.

Filter coffee is thrown away at the end of the day (at the latest) and not stored for further consumption. According to CVUA, the same applies to cold brew coffee, unless microbial safety and product quality are ensured in another way: such as through pasteurization or sterile filling, etc. If the brewing process takes longer than two hours, cold brew should always be stored in the refrigerator to prevent the growth of microorganisms. Homemade cold brew should then be stored at the right temperature and in the dark.

Cold Brew Hygiene - Conclusion

Whether a coffee company is just starting out with cold brew, has decided to expand their current operation, or is doing it on a small scale at home or in a cafe , food safety is of utmost importance for cold brew. In some cases, this means adopting more standardized brewing procedures - which can take some time to get right. However, a good place to start is simply following standard food safety procedures and checking local health and safety regulations. And then you'll be good to go with cold brew!