Oil Management

What is the Best Way to Check Oil Quality?

Resolving the TPM vs FFA Debate

At Klipspringer, we’ve been helping manufacturing and hospitality businesses to ensure food compliance for over 20 years. By removing all guesswork from food oil management, we’ve modernised food safety for the likes of McDonalds, Whitbread, Chopstix, Wasabi, and Five Guys.  

One of the most frequent questions we receive from our customers is: which method of checking oil quality is most accurate, compliant, and objective? This article aims to answer that question, addressing a much-contested area of food oil management: the TPM (Total Polar Materials) vs FFA (Free Fatty Acids) debate.

Read on to find out more.  

Why does frying oil need testing?

Frying produces exceptionally flavoursome food. It is an inexpensive, rapid, and popular way of cooking, which delivers the ultimate food sensory trifecta of “golden, brown, and delicious”, or “GBD”.  

However, this trifecta is only guaranteed if the food in question is fried in safe, high-quality oil. Past a certain level – where the oil is not brand new, but rather from B-C on the below graph – this quality is jeopardised by the repeated use of oil, which causes it to degrade. When oil is used continually, an increasing number of chemical reactions occur, leading to alterations in its composition.  

As cooking oil degrades, so does the taste, texture, and overall flavour of the food. For manufacturers and hospitality businesses that prioritise product consistency, this can be a pressing issue.  

Product integrity is another area compromised by flawed oil management processes. In the worst-case scenario, it can expose customers to the build-up of acrylamide – a cancer-causing chemical.  

On the other side of the coin is oil wastage. Research has shown that, surprisingly, most businesses prematurely discard usable oil due to basic or outdated testing methods. Amid astronomical rises in oil prices, a growing number of restaurant operators are arriving at the same conclusion: monitoring oil quality ensures compliance, prioritises sustainability, and significantly cuts costs. The only question remaining is how best to do it.  

What are the most common oil testing methods?

Currently, there are three predominant oil testing methods used in the industry. The first is simple, but amateurish. The second is relatively accurate, but subjective. The third is eco-friendly, cost-saving, and entirely objective.  

Read on to learn about the core differences, pros, and cons of each method.   


Method #1 – Visual Inspection 

Unfortunately, many restaurants still change their oil based on a quick visual check. While some chefs with vast amounts of experience can make informed guesses about when to change their oil, their decision is still subjective. It stems from the “we’ve always done it that way” rationale which has come to harm many businesses over the years, whether it be through unnecessary expenditures, unsustainable practices, or audit non-conformances.  

In this day and age, taking a quick glance at a batch of cooking oil and deciding if it’s safe simply doesn’t cut it. This is twofold: the rate of darkening differs from oil to oil, and is also dependent on filtering practices and product types. Overall, visual inspection is better than no method of oil monitoring, but there are more accurate options available.  

Method #2 – FFA Measurement (Test Strips) 

High levels of FFA, or Free Fatty Acids, directly correlate to off-colours, off-odours, and off-flavours in fried food products. FFA is typically measured using test strips. After being dipped into the oil, a range of colours appear on the strip. This is then compared to a colour reference chart to determine FFA levels. Standard test strips measure free fatty acid levels from 2% up to 7%, with 5.5% to 7% as the discard range.  

So, just how effective are FFA Test Strips?  

With an overall accuracy of roughly 80%, these strips offer greater compliance than any visual inspection, but don’t provide the same assurance nor peace of mind as other methods. This is primarily because the comparison of the strips’ colouring with the colour chart is still subjective to inadequate or distorted lighting, and strips can also easily be contaminated by improper storage.  

Studies have found that monitoring methods based on dielectric constant provide more “objective and valuable results” than those based on colorimetric reactions. In other words, methods that go beyond surface-level colouring – outlined below – are more reliable.

Dielectric constant-based methods are also less likely to be single-use, unlike test strips, which result in an ongoing cost of around £300 per year.  

Overall, FFA Measurement is still a reasonable solution for food oil monitoring, but isn’t particularly ground-breaking given modern technological advances. As explained above, there is nothing inherently wrong or non-compliant about it. But, for businesses seeking to go the extra mile, other more innovative options are out there.    

Method #3 – TPM Measurement (Food Oil Monitors) 

Devices which determine cooking oil quality by TPM, or Total Polar Materials, remove the subjectivity found with previously summarised methods. By basing data on changes in the dielectric constant, handheld TPM devices – usually a Food Oil Monitor – are greater in accuracy than FFA-based methods.  

TPM Measurements is the most current method utilised in commercial kitchens. Legislatively encouraged across Europe, the go-to critical parameter for TPM limits falls between 24% to 27%. A TPM reading of higher than 25% is considered the discard point in many European countries.  

Best used at the end of each trading day, when the oil is still hot, Food Oil Monitors are efficient and fast to operate. Kitchen staff simply have to place the sensor stem into the vat of oil, and then use a gentle stirring motion until the light at the top of the instrument begins to flash. If the Monitor flashes green, the oil is safe to use again. If it flashes amber, the oil needs changing soon. If it flashes red, the oil requires immediate changing.  

For smaller establishments, a potential drawback of Food Oil Monitors is the upfront cost – usually in the region of £400. However, once purchased and implemented, the Monitors typically show a return on investment within six months, and should last for three or more years. What’s more, these Monitors can be specifically calibrated to various oil types, and are able to verify temperature, as well as oil quality.  





Visual Inspection

Simple eye test based on oil colour

  • Speedy

  • Inaccurate

  • Dependent on individual judgement

  • Lack of product integrity & consistency

FFA Measurement

Uses test strips and a colour chart to measure Free Fatty Acids

  • Relatively accurate (around 80%)

  • Compliant

  • Single-use (£300 per year in ongoing costs & wastage)

  • Subjective to inadequate or distorted lighting

  • Contaminated by improper storage

TPM Measurement

Uses a Food Oil Monitor to measure Total Polar Materials

  • Uses the dielectric constant for high accuracy

  • Compliant

  • Objective

  • ROI within 6 months

1. Upfront cost of around £400

Hopefully this summary has given you a structured insight into the best ways to check oil quality, and has provided some clarity in settling the age-old debate between FFA and TPM.  

Want to quickly outline each oil monitoring method’s pros and cons with your team? Refer to the above table for a concise overview.  

For a concrete example of how Food Oil Monitors have helped companies increase compliance and cut oil usage, read about how Whitbread made savings of up to 52%. 

Cooking Oil – Rising Prices, Needless Costs and Unsustainable Practices

In 2022, oil dominated global headlines: a constantly revolving door of rising oil prices, supply chain issues, and sustainability breaches.

Countries worldwide are admitting to massive shortages, with even oil-rich countries like Saudi Arabia revealing that their reserves are running out.

Lower-income households struggled to afford cooking oil – let alone fill up their petrol tanks – while protests called for windfall taxes on the soaring profits of energy giants like Shell and BP.

Rising Oil Prices

On June 8, the global oil price rose above £123 per barrel ($147), matching the all-time high price points of the 2008 recession.

Cooking oil prices have also increased astronomically, doubling to $1.90 (£1.60) per litre in the UK, and $2.72 (£2.29) per litre on international average.

The current rises in oil prices are unprecedented, and are being caused by factors such as:

  • The COVID-19 pandemic
  • Increased biodiesel demand in the EU
  • Russia’s invasion of Ukraine
  • Extreme weather in Western Canada and South America (prominent areas of global oil exportation)

These circumstances culminated in strong global demand for oil, but extraordinarily weak supply.

At Klipspringer, we watched in disbelief as oil prices reached near-unaffordable levels, but few companies implemented failsafe methods to cut waste, save on costs, and increase sustainability.

In commercial kitchens, the dangers of unsafe oil are well-known, particularly relating to acrylamide build-up.

Despite this, research has indicated that most companies actually discard their cooking oil more often than necessary.

Why is this?

Why Are Most Companies Changing Oil Unnecessarily?

In our experience, there are three key reasons why food cooking oil is being changed prematurely…

1) Status quo. “It’s always been done this way”. Nobody knows why, but the procedure hasn’t changed, and nobody wants to be the person who risks changing it. This line of thinking typically sees oil changed once or twice a week, or every Friday morning, or when fish and chips are on the menu.

2) Visual checks. “It looks like it needs changing.” This is always based on experience, and whilst there are many trained eyes in commercial kitchens, colour is subjective. What looks like a subtle difference in oil appearance can make a massive difference to its working life.

3) Colorimetric methods. The most common colorimetric method is test strips and a colour chart. This measures FFA, or Free Fatty Acids, which directly correlate to off-colours, off-odours, and off-flavours in fried food products. While compliant and reasonably accurate (usually around 80% accuracy), colorimetric methods are still subjective to human error, and can be contaminated by improper storage.

What Is the Best Way of Knowing When Oil Needs Changing?

At Klipspringer, based on our twenty-plus-years’ experience as the industry leaders in removing the guesswork from food oil management, we recommend the following steps to maximise your oil life, in-keeping with the below graph of oil degradation.

  • Make it measurable. Oil quality should be measured as an arbitrary number, and a threshold set for changing the oil. Regular checks mean oil life is then extended to its maximum without compromising product quality.
  • De-technicalise oil management. All unnecessary complexity should be removed from oil-checking and changing procedures. Any team member should be able to check the oil quality and then make an entirely objective decision as to whether it needs replacing. This is only possible once arbitrary, digital measurement has been implemented.
  • Report. Every oil quality measurement should be recorded. As should the date and time when the oil was last changed. Management should review this on a regular basis to make sure oil is not being changed too regularly or too late. A fully documented ‘audit trail’ also supports effective kitchen management and circumvents non-conformances.

In terms of practically implementing these steps, we recommend a solution based on neither status quo, nor visual checks, nor colorimetric methods.

This solution has been used by the likes of Five Guys, McDonalds, and Whitbread to refine their frying process, conduct eco-friendly practices, and cut their oil usage by half.

Click here to find more about this solution.

WEBINAR: Six Strategies for Maximising Oil Life Without Compromising Quality

On 1 June 2022, for the first time since late March, the global oil price rose about $117 per barrel (£93.47). Amid supply chain uncertainty and soaring prices, it has never been more crucial for the hospitality industry to maximise the life of cooking oil. But how can that be done without negatively impacting the safety and quality of your menu?  

At Klipspringer, we decided to host a webinar answering exactly that. Led by a panel of oil management experts, this webinar detailed six actionable steps to ensuring that your food oil is compliant, consistent, and methodically conserved.

Using relevant clips from the webinar, this article breaks down each step into concise, digestible chunks. It answers some of our mostly commonly asked questions, including: 

When should I change cooking oil? 

How do I check oil quality? 

Does filtering help to extend oil life? 

Navigate the menu below to be directed to the step most applicable for your food oil needs, or keep reading for a holistic insight into one of the most pressing issues the hospitality sector faces today.   

You can also view the webinar in full below:

Step 1 - Choosing the Right Oil

As put by Vincent Igoe, Managing Director for Olleco Scotland: “In my 25 years in the industry, I’ve never seen markets like this”. The astronomical current price of oil is unprecedented, and is being caused by factors such as: 

  • A knock-on from the Covid-19 pandemic 
  • Extreme weather in Western Canada 
  • Increased biodiesel demand in the EU  
  • Adverse weather across South America 
  • Russia’s invasion of Ukraine  

These circumstances have culminated in strong global demand for oil, but extraordinarily weak supply. In light of this, selecting the right type of oil has never been more crucial.  

When choosing the best oil for frying, there are five overarching aspects to consider: 

a) Taste 

b) Performance 

c) Cost 

d) Safety 

e) Sustainability 

Once you’ve evaluated each of these aspects and narrowed your search down to one or two types of oil, refer to the below chart for the specific benefits of three widely used oil types.  

Rapeseed Oil

Vegetable Oil

Long-Life Oil

Non-genetically modified seed

Produced from genetically modified soya 

Non-genetically modified seed 

Extended life

Extended life

Lasts 2x longer than extended life oils 

Anti-foaming agent (makes it safe for use in fryers) 

Contains anti-foaming agent 

Lasts 2x longer than extended life oils 

Anti-foaming agent (makes it safe for use in fryers) 

Contains anti-foaming agent 

Contains anti-foaming agent 

High smoke point 

One of the UK’s best-selling standard cooking oils 

Certified by RSPO (Roundtable on Sustainable Palm Oil) 

Step 2 - Choosing the Right Fryer

Once you’ve selected the right oil type for your needs, an effective oil fryer is the next requirement. Watch the above clip for advice from Michael Eyre, Culinary Director at Jestic Ltd, on various industry staples, including:

  • Simple Fryers (£)
  • Gravity (External) Filtration Fryers (££)
  • Pumped (Internal) Filtration Fryers (££)
  • Digital Fryers with Built-In Filtration (£££)
  • Low Oil Volume Fryers (££££)

Step 3 - Fryer Operation and Filtering

After selecting an appropriate oil fryer, it’s important to learn how it operates. This requires thought about food types, (auto)filtering, skimming, loading, and frying temperatures. For example, does your food type contain crumbs (e.g. breaded chicken)? If so, do you have a workable particulate filtration system in place to catch solid impurities that might fall into your oil?

Read on for a three-part process to ensure the best frying practices.

Before Frying:

  • Don’t skip ‘melt-mode’ in your morning check-ups and clean
  • Never fill the basket over the vat
  • Respect the recommended quantity per basket (don’t overfill the basket)
  • Ensure that oil is at cooking temperature before dropping the basket in
  • Cook food items either always from frozen or always from fresh (for better consistency)

During Frying: 

  • Ensure correct frying temperatures (frying at higher temperatures does NOT decrease frying time) 
  • Never place a basket in the oil without using a timer 
  • After placing the first basket in oil, allow 30 seconds before dropping the second basket into the same vat
  • Program an alarm to remind cooks to shake the basket during the cooking cycle  

After Frying:  

  • Drain/shake the basket over the vat 
  • Skim the vat regularly throughout the day 
  • Top-up oil throughout the day 
  • Use ‘night’ covers (to prevent debris falling into the oil and reduce contact time with light) 
  • Test quality of oil at least once daily (after the daily filtration/clean) 
  • Proactively filter the vats during the day (the more often the better) 
  • Use the ‘idle’ feature when the fryer is not in use 
  • Change filter paper daily 
  • Polish oil daily 

Step 4 - Monitoring Oil Quality

As summarised by Murray Carlyon, Managing Director at Klipspringer, there are three overarching reasons to monitor oil quality.  

Firstly, to reduce costs and wastage. An effective oil monitoring system results in significant savings, both economically (costs) and environmentally (wastage). Instead of discarding perfectly usable oil – a costly and unsustainable outcome – businesses are now using Food Oil Monitors for maximum accuracy. For a minimal upfront cost, these monitors offer a comfortable ROI, usually within just six months. Click here to read about how Whitbread’s use of a Food Oil Monitor reduced their oil consumption by up to 52% across their 1,200 different venues 

Secondly, to maintain product consistency. Most kitchens change their oil either based on colour (when it goes dark/black, using single-use test strips and a simplistic colour chart) or schedule (twice a week – because it has always been done that way). Led by the likes of Wasabi, McDonalds, and Five Guys, hospitality businesses seeking to distinguish themselves from the crowd are standardising the use of Food Oil Monitors to guarantee such consistent menu quality  

Thirdly, to ensure product safety. Paramount to any hospitality business is consumer welfare. As shown by the figure below, the frying process can release a variety of polar compounds (e.g. free fatty acids), which are in turn associated with acrylamide build-up. This customer-harming, cancer-causing chemical can reach dangerous levels when relying on subjective oil quality monitoring methods.  

A percentage reading of Total Polar Compounds or Total Polar Matter (TPC% / TPM%) is reliably used in the food industry as a measure of oil degradation. High levels of TPC can negatively impact product taste, texture, and appearance, as well as causing various health disorders, both short-term (e.g. gastrointestinal disorders) and long-term (e.g. risk of heart disease).  

A growing number of countries across Europe are legislating TPC percentages, typically around the 24-27% mark. While there is no existing legislation in the UK, leading companies are setting their own standards around a similar benchmark, using digital solutions to take the subjective guesswork out of monitoring oil quality.  

Step 5 - Pumping and Storing Waste Oil

Watch the above clip for advice regarding pump stations, filtration, and waste oil tanks. It addresses the following questions: 

  • How do I get oil into a fryer? 
  • How do I remove waste oil from my fryer? 
  • Where do I store waste oil? 
  • How can my waste oil get collected? 
  • How can I monitor waste oil? 

Step 6 - Returning Used Oil

Getting the most longevity and value out of your oil supplies is imperative for two reasons: profitability and sustainability. As one of the largest contributors to carbon footprints in commercial kitchens, oil is best suited to a circular economic system (illustrated below). Leading oil suppliers now offer the service of collecting ‘waste’ oil in the same containers it is delivered in – and they even pay for it, balancing the value of your reused oil against the costs of your fresh oil.  

Implementing these six steps will ensure that your oil quality remains compliant, consistent, and methodically conserved. Customer satisfaction will increase, costs will decrease, and your business will be more adeptly prepared to meet any sustainability targets and initiatives.  

Watch the below clip to hear Surendra Yejju, Executive Chef at Wagamama, outline how these six steps have helped teams across Wagamama venues nationwide.  

Interested in learning how other leading food and hospitality companies have benefitted from food oil monitoring?  

Click to learn how Whitbread reduced oil savings by 52%

Reducing the Risks of Acrylamide in Cooking Oil

In October 1997, cows and fish on the Swedish Bjare peninsula suddenly started dying.

The cause was eventually discovered – construction workers had been pumping sealant into holes in a nearby railway tunnel which contaminated the water with acrylamide. Not only did this kill those cows and fish, it is a proven carcinogen for animals – and a probable carcinogen for humans.

The problem with acrylamide is that it is found in many of the foods that we eat, especially starchy food with higher levels of asparagine such as crisps, chips, toast, cakes, and biscuits. One other place where people might not think acrylamide resides is in cooking oil.

Acrylamide in food

Acrylamide has long been seen as a risk factor in some foods. It develops as a natural by-product in food through the Maillard reaction, a form of non-enzymatic browning where a chemical reaction occurs between amino acids and reducing sugars.

Food safety experts have been studying acrylamide since the early 2000s, and in 2013, the European Commission introduced ‘indicative values’ for food groups most associated with acrylamide. These were a guide rather than regulatory limits, but as of April 2018 food businesses in Europe have been required to put in place practical steps to manage acrylamide in their food management systems. Acrylamide cannot be fully eliminated, but it can be reduced and this is what new EU regulation is aiming for.

What are the risks?

Potential health risks of acrylamide include cancer and damage to the nervous and reproductive systems, although risk levels differ depending on lifestyle and consumption levels.

The Committee on Mutagenicity have suggested that acrylamide could damage DNA, stating that ‘there is no level of exposure to this genotoxic carcinogen that is without some risk’. In 2014, the European Food Safety Authority supported the CoM’s views, and the Food Standards Agency has been keeping an eye on acrylamide levels in food since 2007, recommending that when cooking foods like bread and potatoes, they are cooked to the lightest colour acceptable.

Cooking oil and acrylamide

Acrylamide is not naturally found in cooking oil, but if starchy foods such as potatoes are fried in oil, and that oil is reused, then acrylamide can build up to dangerous levels. This is not a huge concern for domestic cookery (unless chip fryers are used and oil is not replaced) but it might worry a lot of people who work in the food industry and use cooking oil on a daily basis, because if cooking oil is used beyond its working life, acrylamide is likely to build up and could harm consumers.

It is recommended that cooking oil should be replaced when it reaches 25% Total Polar Compound (TPC). There isn’t a direct correlation between acrylamide and TPC levels but it’s widely acknowledged that oils with a high TPC level also contain higher levels of acrylamide.

Both sides of the coin

A common problem in the food sector is knowing when oil has reached an unacceptable TPC level. Some kitchens keep reusing their oil, unaware that it has become dangerous for consumers. This is often due to traditional oil changing schedules, subjective oil checks based on colour or test strips, poor awareness of acrylamide dangers or attempting to increase oil life and cut costs.

Perhaps surprisingly, our research has shown that many businesses are actually erring on the side of caution and discarding oil which is still safe to reuse. As sustainability programmes are given greater focus, key foodservice and hospitality brands such as Whitbread are leading the way in reducing oil usage by up to 52% – simply by implementing regular oil quality checks using an electronic food oil monitor.

One of the best ways to ensure that your cooking oil is safe to use is to invest in a food oil monitor. At Klipspringer, we recommend the FOM330 Ebro oil monitor to check your oil at regular intervals. It is a handheld and portable instrument which is extremely simple to use, quickly measuring TPC levels in oil to a high standard of accuracy. This monitor not only makes companies more efficient, by preventing oil wastage, it also makes them safer and prevents acrylamide build up.

Advice for the Food Industry

There are a few simple pieces of advice that any business in the food industry which cooks with oil, or cooks food containing acrylamide, should follow:

  • Abide by the acrylamide standards relevant to your region
  • Where possible, cook food at lower temperatures for less time
  • Cook food to a maximum light golden brown colour
  • Regularly check the levels of TPC in your oil and discard at 25%