Pink Slime Build-Up On Your Glasswasher


Keeping your glasswasher clean is imperative to good health and safety and ensuring proper beer taste and presentation.

Even the smallest imbalance inside your machine can have a negative effect on beer head retention, effervescence and lacing on the glass. In turn, this can damage your businesses beer yields and wastage figures.

One of the most common issues is pink slime developing inside the glasswasher cabinet. This usually appears around the door hinges, crevasse of the tank and, in the most serious cases, even the flat stainless-steel surfaces around the cabinet.

This article looks at the common causes and methods for prevention

Is It Normal?

Many operators think that pink slime building up is normal practice and just a sign that the glasswasher is due for a deep clean. Whilst it is true that build-up deep cleaning will resolve the problem, publicans should also investigate the root cause of why it is developing, particularly if it is returning frequently.

What is The Pink Slime?

Plain and simple, the pink or orange slime is bacteria growth, not too dissimilar to that which you may have seen developing in other humid areas around your home, such as a shower or bathroom.

The most common type of bacteria is a form of non-contagious salmonella mould. However, there are hundreds of different variants that could develop, some of which can pose a serious health risk for your customers, so it is important to deal with the problem quickly.

Pink Slime Bacteria on Dishwasher

What Causes It?

If not maintained correctly, a glasswasher can be a perfect place for bacteria to develop. The humid environment is ideal for bacteria growth and this can be exasperated by incorrect temperatures or a source of food inside the machine.

1. Temperature

If configured correctly, the machine should maintain a suitable temperature to prevent bacteria development. However, many external effects can impact its ability to do so. The most common issue is operators leaving the door to the machine open for prolonged periods, particularly when loading glasses. This is often exasperated in winter as the cold air meets warm air, causing excess humidity and condensation.

2. Food Sources

Any type of protein, alcohol, sugar or fat is the perfect source of food for bacteria growth. These are common introduced to your glasswashers when glasses are not appropriately emptied or pre-washed. Beer are exceptionally high in protein. Fruit juices, soft drinks and cocktails are also extremely high in sugar. Tea and coffee cups are also a significant factor, as these usually contain dairy fats.

Recommendations for Prevention

Simple changes in operation and practice can therefore prevent the pink slime from developing in the first place:

1. Keep door shut whenever turned on.

Glass trays should be loaded separately and then loaded into the glasswasher together. Never load glass trays with the machine door open.

2. Keep door open at the end of the day.

Wipe down the inside of the tank with a sanitiser and then a dry cloth to remove any damp or condensation.

3. Prevent drink waste from entering.

Ensure all glasses are fully emptied before being loaded. It is recommended to give each a quick pre-rinse to ensure any alcohols, wheats or sugars are removed.

4. Do not mix crockery & glasses.

A glasswasher should be limited to washing glasses. Avoid washing crockery used for teas and coffees and even shot glasses used for dairy based drinks, such as Baileys. These should be washed separately as glasswasher detergents cannot break down fats, greases and tanning. A dishwasher is much better suited.

5. Ensure the correct temperature.

Check the configuration of your machine to ensure it is delivering washes correctly. Our recommendation for a glasswasher is a 55c wash and a 75c rinse, as this will allow any detergents and rinse aid to work optimally. Any colder, and washes won’t be effective. Any hotter and you risk burning chemicals onto the glass, leaving etching or spotting marks.

6. Check chemical dosage

In some cases, either a lack of appropriately dosed chemical or too much chemical can cause bacteria to build up. Always refer to manufacturer’s specifications and your chemical suppliers’ concentrations.

7. Switch chemical supplier

Some cheaper chemicals that are high in caustics, bleaches or glass refurbishing agents have been found to mask the problems of dirty glasses but do very little to prevent bacteria growth. These types of chemicals are also likely to damage silicone pipework inside your machine.

8. Check the location of the machine.

In ideal cases, the machine will not be located next to any appliances that are likely to be a source of cold air, such as ice machines or fridges.

Reccomendations for Deep Cleaning

1. Wash your machine with sanitiser.

It is good housekeeping to wash out your machine with a kitchen sanitiser once a week. Simply wipe down the inside of the machine and leave for the recommended contact time (usually 30 seconds). Then perform two empty wash cycles to rinse it away.

We recommend our Jeyes C1 Liquid Cleaner Sanitiser as it is certified to EN1276 and is effective against Salmonella. Avoid any non-kitchen sanitisers and bactericidal hard surface cleaners that are commonly used in front of house cleaning, as these are not always “food-safe”.

2. Ensure regular renovation

Glass refurbishing powder can also help but shouldn’t be completed too regularly as it can damage glasses and machine components if they are overcleaned.

3. Get your machine serviced.

We recommend an annual service by a qualified engineer to ensure that there are no hidden blockages, build-ups in pipework, filters or pumps that could be aiding bacteria growth.