What Is Diastase Activity in Honey and Why the Number Matters More Than the Label

Introduction

A few years ago a beekeeper in Uttarakhand sent a batch of honey for lab testing before export. The honey looked perfect. Dark, thick, fragrant. Exactly what you would want. The lab report came back and everything looked fine except one number. The diastase number had dropped below the minimum international threshold.

The honey was rejected.

Not because it tasted bad. Not because anything visible was wrong with it. But because that one number told the laboratory something the label never could, this honey had been handled in a way that quietly destroyed one of its most important natural markers.

That number is called the diastase activity score, or diastase number. And if you are serious about understanding honey quality, whether you are a consumer, a buyer or a producer, this is one of the most important things you can learn to read.

This blog explains what diastase activity is in plain language, what the number means, what international standards say, and what a low score actually tells you that a label never will.

Key Takeaways

• Diastase is a natural enzyme that bees add to honey during collection and ripening. It is measured as a diastase number (DN) in Schade units.

• Diastase is highly sensitive to heat. When honey is heated above safe temperatures, diastase breaks down and the number drops. This makes it one of the most reliable indicators of how honey was processed and handled.

• The international standard set by the Codex Alimentarius requires a minimum diastase number of 8 for most commercial honeys. A DN below 8 is considered a red flag for overheating or improper storage.

• Some honey types, such as acacia and citrus, are naturally low in diastase. For these, the standard allows a DN as low as 3, but only if the HMF level is also below 15 mg/kg.

• Fresh, raw honey typically has a DN of 15 to 30 or higher. Dark honeys like forest or sidr honey can naturally reach even higher values.

• Diastase can be artificially added to honey to fake a passing score. This is why the diastase number works best when read alongside HMF content and other quality markers.

• A honey that passes on diastase and fails on HMF, or vice versa, tells a more complete story than either number alone. The two markers are best read together.

• For brands, a published diastase number is not just a regulatory compliance figure. It is a proof point. It shows the honey was never quietly cooked before it reached you.

What This Blog Covers

• What Is Diastase Activity in Honey?

• Where Does Diastase in Honey Come From?

• What Is the Diastase Number and How Is It Measured?

• What Does a Good Diastase Number Look Like? International Standards Explained

• Why Heat Is the Enemy of Diastase Activity

• Which Honeys Naturally Have Low Diastase and Why That Is Not Always a Problem

• Diastase and HMF: Why You Need to Read Both Numbers Together

• Can Diastase Be Faked? What Sophisticated Fraud Looks Like

• How to Read a Honey Lab Report: Diastase in Context

• Diastase Activity at a Glance

• Conclusion

• FAQs

What Is Diastase Activity in Honey?

Start with the simplest version.

Diastase is an enzyme. Enzymes are proteins that trigger chemical reactions inside living things. In honey, diastase belongs to a group called amylases, which break down starch into simpler sugars.

Diastase, also known as alpha-amylase, is one of the dominant enzymes in honey alongside invertase and glucose oxidase. It is added to honey by the bee during the collection and maturation of flower nectar. Nano-lab

The reason diastase matters so much as a quality marker is not really about what it does to starch. It is about what happens to it when honey gets hot.

Diastase has become the gold-standard marker for honey quality testing because of one critical property: it is highly sensitive to heat. When honey is heated during pasteurisation, improper storage or adulteration processing, diastase is progressively destroyed. Goodfriend Honey Co.

Think of diastase as a living witness inside every jar. If the honey was handled carefully, kept cool and never overheated, the witness is still there and the score is high. If the honey was rushed, heated, stored badly or interfered with, the witness starts to disappear and the number falls.

That is what diastase activity measures. Not just an enzyme level. A handling history.

Where Does Diastase in Honey Come From?

This is worth understanding because it explains why diastase is such a reliable quality marker.

As honeybees collect nectar, they add enzymes from their hypopharyngeal glands, which are specialised glands in the head. The ripening process, where bees fan their wings to evaporate moisture and gradually transform the composition of the nectar, develops and concentrates this enzymatic activity over several weeks. By the time the cells are capped with wax, the honey's sugar chemistry has been fundamentally changed from what the bees originally collected. Nettiesbees

Diastase is not something added by a manufacturer. It is not a supplement or an additive. It comes from the bee itself, built up slowly during the natural ripening of the honey inside the hive.

This is why its presence and strength tell you something meaningful. A high diastase number means that the natural process the bee started was not interrupted or damaged before the honey reached you.

Diastase activity is a proxy for the preservation of all heat-sensitive compounds in honey. If the diastase is intact, the other beneficial enzymes, vitamins and volatile aromatic compounds are likely intact as well. Nettiesbees

In other words, diastase is not just one quality marker. It is a signal about the condition of everything else in the jar.

What Is the Diastase Number and How Is It Measured?

The diastase number, often written as DN, is the unit used to express how much diastase activity is present in a honey sample.

The diastase activity is expressed in Schade units, also known as the diastase number. It is defined as the amount of enzyme that will convert 0.01 grams of starch to the prescribed endpoint in one hour at 40 degrees Celsius under controlled test conditions. nih

The test is done in a certified laboratory. A sample of honey is prepared, mixed under controlled temperature and the activity of the enzyme is measured against a standard. The resulting number is the DN.

For all three recognised testing methods, the activity is given as the diastase number in accordance with the Schade scale and can therefore be used for quality assessment in accordance with international standards. Qsi-q3

The three main testing methods used globally are the Schade method, the Phadebas method and the Nitrophenol method. All three express results on the same Schade scale, which means results should be broadly comparable across labs using different methods.

What Does a Good Diastase Number Look Like? International Standards Explained

This is the section that matters most if you are trying to read a lab report or evaluate a honey's quality claim.

The Codex Alimentarius international honey standard requires a minimum diastase number of 8 for commercial honey. Fresh, raw honey typically has a DN of 15 to 30 or higher, depending on the floral source and the bee subspecies. A DN below 8 raises red flags: the honey has either been heated above safe thresholds, stored improperly for extended periods, or both. Goodfriend Honey Co.

Dark honeys like forest or sidr honey can naturally reach DN values of 17 to 32. Higher numbers mean fresher, less processed honey. Kashmiril

It is important to note that the minimum of 8 is a floor, not a target. A honey scraping by at DN 9 has technically passed the standard. But a honey sitting at DN 25 is telling a very different story about how it was made and kept.

Why Heat Is the Enemy of Diastase Activity

This is where science becomes practically important for everyone in the supply chain.

Active enzymes are very sensitive to high temperatures and will lose their activity when they exceed a certain temperature. Beekeepers often use concentrators to process natural honey into concentrated honey at high temperatures, and this leads to inactivation of a large number of active substances. nih

Diastase activity decreases with increases in temperature and heating time. Honey with a higher initial DN, such as acacia at 18.30 DN and longan at 22.63 DN, showed a sharp decline in diastase activity in the first two hours at 80 degrees Celsius. Heating at 40 degrees Celsius and 60 degrees Celsius for two hours had only a minor effect on diastase activity, suggesting that 35- 40 degrees Celsius is considered the best processing temperature for honey to preserve enzyme activity. nih

What this means in practice is straightforward. Every time honey is heated above 40 degrees Celsius, it loses diastase faster. Every time it sits in a warm warehouse, it loses a little more. By the time heavily processed commercial honey reaches a supermarket shelf, much of what made it biologically interesting may already be gone. The label will still say honey. The DN will tell you what actually happened to it.

Honeys exhibiting lower HMF content and higher diastase activity are generally considered to be fresher and less overheated. Storage conditions can impact diastase activity, as enzymatic inactivation may also occur upon prolonged storage. ResearchGate

Which Honeys Naturally Have Low Diastase and Why That Is Not Always a Problem

This is an important nuance that stops the diastase number from being misread in both directions.

Not every honey with a low DN has been mishandled. Some honeys are naturally lower in diastase because of the type of nectar the bees collected.

Concessions have been made for honeys with naturally low diastase activity, such as citrus honey which has a lower moisture content in the nectar and therefore requires less manipulation by the bee. For these honeys, the enzyme activity should not be less than DN 3, and the HMF concentration should not exceed 15 mg/kg. ScienceDirect

Acacia honey can have naturally low DN, sometimes around 3 to 8. Orange blossom and citrus honey have a similar low-enzyme profile. This is not a sign of poor quality. It is simply the nature of that flower. The international standards account for this by allowing a DN as low as 3, provided HMF stays below 15 mg/kg. Kashmiril

The key distinction to understand is this:

A low DN in acacia honey with low HMF is normal. A low DN in forest honey with rising HMF is a problem. Context is everything.

Diastase and HMF: Why You Need to Read Both Numbers Together

If diastase is the most important enzyme marker in honey, HMF is its essential partner.

HMF stands for hydroxymethylfurfural. It is a compound that forms naturally in honey when sugars break down over time or under heat. In fresh raw honey, HMF is close to zero. As honey ages or is heated, HMF rises.

Fresh raw honey has almost zero HMF. High HMF above 40 mg/kg signals that honey has been overheated, stored improperly or is very old. Diastase and HMF have an inverse relationship. They move in opposite directions. Kashmiril

The Codex Alimentarius has established that in honeys with a DN less than 8 and higher than or equal to 3, the HMF must not be higher than 15 mg/kg. If DN is equal to or higher than 8, the HMF limit is 60 mg/kg. ScienceDirect

Reading the two numbers together gives you a much more complete picture:

A honey with DN of 12 and HMF of 8 mg/kg is outstanding. A honey with DN of 4 and HMF of 55 mg/kg is a serious concern. Kashmiril

Can Diastase Be Faked? What Sophisticated Fraud Looks Like

This is the part that matters most for serious buyers and brand owners.

The short answer is yes. Diastase can be artificially added to honey to make a failing batch appear to pass.

In practice, diastase is sometimes artificially added to honey to meet legal requirements, to cover ion exchange treatment, heat or storage damage, or after dilution with sugar syrups which have no natural diastase activity. Such manipulated honeys can show differences between the results of the three diastase determination methods, which may indicate the presence of foreign sugars or adulteration. Qsi-q3

This is why running all three recognised diastase tests and cross-checking results is considered important for any serious quality verification. Authentic honey should produce broadly comparable results across all three methods. Significant inconsistencies between methods are themselves a signal worth investigating.

It is also why the diastase number should never be read in isolation. A honey that passes on diastase but shows unusual sugar profiles, atypical HMF patterns or unexpected pollen results deserves closer scrutiny. Good honey quality verification uses a panel of tests, not a single number.

How to Read a Honey Lab Report: Diastase in Context

If you have a honey lab report in front of you and want to understand what the diastase number is telling you, here is a practical guide to reading it in context.

The most important habit when reading a lab report is to never read one number in isolation. A single metric can be managed or manipulated. A consistent set of metrics that all tell the same story is much harder to fake.

 

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Diastase Activity at a Glance

Conclusion

The beekeeper in Himachal Pradesh whose honey got rejected did not set out to produce bad honey. He just did not know that one number, measured in a lab he had never visited, was recording exactly what happened to his honey between the hive and the export container.

That is what diastase activity does. It keeps a quiet, factual record. It does not care what the label says, what the colour looks like or how the honey is marketed. It only responds to what actually happened: the temperature, the time, the handling, the care.

For consumers, the practical lesson is this. A honey with a published diastase number above 15, alongside a low HMF reading, has cleared a bar that most commercial honeys never reach. It is not proof of perfection. But it is evidence of intent. It means someone in that supply chain understood what these numbers mean and cared enough to keep them high.

For wholesale buyers and food professionals, the diastase number is one of the most reliable first questions you can ask a supplier. Not what it looks like. Not what the label says. What is the DN?

For brands, publishing this number is an act of transparency that most competitors avoid. And the reason most competitors avoid it is the same reason it matters. Because an honest diastase number, sitting alongside honest HMF data and a clear statement of floral origin, is one of the hardest things to argue with in the honey world.

Numbers do not have an agenda. They just tell you what happened.

FAQs

1. What is diastase activity in honey?
Diastase activity is a measure of how much of a natural enzyme called diastase is present in honey. The enzyme is added by bees during nectar collection and ripening. Its level is expressed as a diastase number (DN) and is used as one of the most important international indicators of honey quality because it breaks down rapidly when honey is overheated or stored badly.

2. What is a good diastase number for honey?
For most commercial honeys, the international minimum is a DN of 8, as set by the Codex Alimentarius. However, fresh raw honey typically scores between 15 and 30 or above. Dark honeys like forest or sidr honey can naturally reach even higher. A DN above 20 alongside a low HMF reading is generally considered a strong quality indicator.

3. Why is diastase used to test honey quality?
Because it is highly sensitive to heat and time. When honey is overheated during processing or stored incorrectly for long periods, diastase activity drops in a measurable and predictable way. This makes it a reliable indicator of how honey was handled between the hive and the consumer, something a label alone can never tell you.

4. Can some honeys naturally have low diastase?
Yes. Acacia honey, citrus honey and orange blossom honey are examples of honeys that naturally have lower diastase levels because of the type of nectar the bees collected. International standards allow a DN as low as 3 for these varieties, but only if the HMF level is also below 15 mg/kg. A low DN in these specific honeys is not automatically a quality concern. A low DN in forest or dark floral honey is.

5. What is the difference between diastase number and HMF in honey?
Diastase number measures how much natural enzyme activity remains in the honey. HMF measures how much of a degradation compound has built up. The two move in opposite directions. Fresh well-handled honey has a high DN and a low HMF. Overheated or old honey has a low DN and a high HMF. Reading both together gives a far more accurate picture of honey quality than either number alone.

6. Can diastase be added artificially to honey?
Yes, and this is a documented form of honey fraud. Diastase can be added to a failing or adulterated honey to make it appear to meet quality standards. Cross-checking results from multiple testing methods and reading DN alongside HMF, sugar profiles and pollen analysis makes this harder to disguise. Significant inconsistencies between test methods can be a sign of artificial addition.

7. Does diastase activity decrease over time even without heating?
Yes. Diastase naturally decreases slowly over time even in honey stored at room temperature. This is one reason test date relative to harvest matters when reading a lab report. Long storage at warm temperatures accelerates this natural decline, which is why proper temperature-controlled storage is important throughout the supply chain.

Sources

1. Codex Alimentarius Commission. Revised Codex Standard for Honey. CXS 12-1981. https://www.fao.org/fao-who-codexalimentarius

2. ScienceDirect. Honey diastase activity modified by heating. https://www.sciencedirect.com/science/article/abs/pii/S0308814607003767

3. PMC National Library of Medicine. Nondestructive Determination of Diastase Activity of Honey Based on Visible and Near-Infrared Spectroscopy. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6480106/

4. ScienceDirect. Accelerated loss of diastase in manuka honey: Investigation of manuka specific compounds. https://www.sciencedirect.com/science/article/abs/pii/S0308814623012323

5. QSI Laboratories. Diastase Testing: Different Methods Schade, Phadebas and Nitrophenol. https://www.qsi-q3.com/wp-content/uploads/2024/05/Newsletter_Diastase-Methods_updated-2022.pdf

6. Phadebas. Diastase Activity in Honey. https://www.phadebas.com/areas-of-use/alimentary/diastase-in-honey/

7. Nettie's Bees. Enzymes in Raw Honey: What Heating Destroys and Why It Matters. https://www.nettiesbees.com/post/the-living-enzymes-in-raw-honey-natures-active-ingredients