All in the best possible taste

What affects the taste of your beverage?
If you are using good quality ingredients and your dispenser is well maintained, the answer is WATER quality. With most vended drinks, over 80% of the ingredients are water.

Taste and odour – the main causes

The commonest complaint of taste and odour problems in water in the UK, is caused by chlorine. Chlorine is used by the local water authority for residual disinfection and to ensure water reaches your tap in the same state at which it leaves the treatment plant. Sometimes it can cause issues by reaction with other materials such as water-borne organics or the plastics in buildings and vending machines. Some of the compounds this creates, such as Tri-HaloMethanes (THMs), are considered harmful, but in most cases the water has an off-taste that can affect coffee, tea and other beverages as well as dispensed cold water.

It is fortunate that chlorine, and some other bad taste and odours are fairly easily removed by activated carbon. Many filter manufacturers offer a wide variety of filters which include activated carbon material, but there are differences to consider when looking at the two main types of activated carbon filter.

Granular Activated Carbon (GAC) is generally good at taste and odour removal, but has the problem of releasing small pieces of black carbon that can be flushed from the filter. Flushing the filter must be done when the filter is installed to remove carbon fines from manufacturing, but during its life due to abrasion between the particles, further fines can be released which can be passed downstream to the machine. GAC filters are normally rated at 5 to 20 microns and this is only achieved through the combination with other filter media for dirt removal.

One manufacturer offers a filter that relies on powdered activated carbon (PAC) and a filter aid being flushed onto a membrane to form a thin layer. This flushing or activation process is crucial for the carbon to be fully effective and requires a good flow of water to achieve optimum activation.

Carbon Block can be more effective than GAC at removing chlorine, taste and odour, and there is almost no release of carbon fines. Carbon blocks use PAC, which is typically bonded or held into a rigid structure. Normally rated from 0.5 to 5 microns, carbon block filters can also be made so they remove harmful bugs like cryptosporidium, which is chlorine resistant. 3M CUNO Filtration offer carbon block filters as standard.

In cold water applications, some leading restaurant chains in the UK specify cyst rated filters to provide additional quality claims for their customers and helps protect their brand from the risks associated with cryptosporidium.

Virtually all machine manufacturers are now using water filters to ensure their dispensed beverages are consistent, and of course the drink tastes good. Also ensuring their machine is protected from damage due to sediments and where necessary harmful and costly scale.

Although they are using filtration, it may not be the best filter optimised for their application/machine. This means a lot of time and investment is made on supplying a first class machine, first class ingredients but poor water quality which results in an overall poor quality beverage and dissatisfied customers. Poor filters can affect the taste of the drink.

Are all filters the same? Of course not! As with any product there are cheapies and some off-the-shelf ‘one solves all’ filters which may not at all be suitable for the particular application.

So, what can you do to ensure you are getting the correct filtration to answer all your needs. Is it worth considering cheap filters and indeed why are they cheap?

Let’s review first some situations that can exist with the cheap filters. They can be less cost than the average filter because they are off-the-shelf. The manufacturer may not offer technical assistance and proof that the correct filtration is being used. You may be lucky and get a filter that fits your machine exactly, and provides a relatively good product water. You may also be lucky with easy filter replacement, without the need for a specialist engineer and a disinfection procedure requiring mains shut-off and downtime. Other reasons for a low price, could be that the filter is manufactured from inferior materials and possibly poor quality filter media.

How can you be certain the filter is absolutely right for your machine and application, and that you are not paying too much for a filter or too little?

The answer is simple; you should contact a manufacturer with good reputation and experience in your area. They can offer to scientifically test the filter and applications. They can offer technical advice from the initial design of your machine to actual installation of the filter, testing and after sales. It is obviously in the interest of filter manufacturers to make absolutely sure that their filters match the exact requirement of the machine supplier. Some also offer training facilities for manufacturers and suppliers.

Here are some more factors to bear in mind when looking for the correct filter.

Materials of Construction & Independent Certification can be crucial factors when choosing your filter supplier. Filters need to be made from materials suitable for contact with drinking water ideally food grade materials and need to be structurally sound. Each country across Europe will usually have its own set of regulations. Currently there is no unified regulation; however there has been some progress to this end which includes some European Norms.

NSF is an American independent test body that ensures filters meet the claims made by manufacturers in America. NSF standard 42 covers the aesthetic affects of water filters and will qualify factors like chlorine and particulate removal ratings. NSF standard 53 covers the health effects of water filters and will qualify factors like the removal of cryptosporidium and reduction in lead levels. NSF also ensures filter construction meets compliance for American standards for contact with drinking water and structural requirements.

WRAS ensure that approved filters comply with the UK drinking water regulations. This means they must use the correct plastics and be able to withstand their stated specified pressures. WRAS does not offer any independent verification of manufacturer’s claims to remove contaminants.

Due to the many options available, it is important to find a reputable filter partner such as 3M CUNO Filtration who can offer the best solution from a number of alternative technologies. This filter partner should supply products that are independently qualified e.g. by NSF or WRAS. Provision of technical backup and support can be important so water problems can be resolved quickly.