Does the Labeled MGO Strength Last Until the Best-Before Date?

The labeled MGO strength is expected to remain accurate through the best-before date, as long as you store the jar correctly. With that said, the MGO level may change gradually over time, meaning the printed grade shouldn’t be treated as a permanent guarantee.

Time and temperature may all influence how MGO develops or declines. On top of this, the best-before date is a quality marker, not the moment your honey suddenly becomes unusable (it’s frequently still safe to consume the honey after this date). 

Put simply, properly stored honey may still be enjoyable beyond the date, even though flavor, texture, and MGO may shift gradually. Below, we take a closer look at what this all means in more detail.

What Does the Labeled MGO Strength Mean?

The MGO number reflects the minimum measured concentration of methylglyoxal, in milligrams per kilogram of honey.

This means MGO 600+ contains at least 600 milligrams per kilogram, MGO 850+ contains at least 850, and MGO 1000+ contains at least 1,000. In other words, these numbers are merely thresholds, but your jar may contain more MGO (or less due to improper storage or if it’s used after the best-before date). For instance, an MGO 850+ label doesn’t mean every jar holds exactly 850.

The MGO grade also simply refers to strength alone. It doesn’t describe the age, serving size, sweetness, or calorie content of the honey.

Does the MGO Level Stay Exactly the Same Over Time?

This depends.

MGO naturally develops from dihydroxyacetone, or DHA, in Manuka honey. Earlier in storage, some remaining DHA may keep converting into MGO. Over longer durations, however, MGO may gradually react with other components in the honey, causing it to naturally decline, and temperature also impacts how quickly all of this happens.

Because of this, an exact lab measurement may rise or fall. In fact, research has found that temperature impacts both DHA loss and MGO formation, with warmer storage speeding up these changes. 

In other words, MGO isn’t fixed. It also doesn’t always improve with age either. It sometimes can, but this depends on various factors, particularly how you store it (more on this below).

What Does the Best-Before Date Guarantee?

The best-before date marks the period during which we expect the honey to hold its labeled quality and MGO strength under the recommended storage conditions.

Keep in mind that “best before” and “use by” are distinctly different dates. A best-before date refers to the expected quality, and a “use by” date applies to highly perishable products where safety may become a concern after that point.

This means that after the best-before date, your honey may still be just as delicious, but the printed MGO strength may be more variable. You also can’t confirm the exact current MGO level through appearance, taste, or texture alone; this is partially why each jar includes a best-before date in the first place!

How Should You Store Manuka Honey to Protect Its MGO Strength?

Keep the jar tightly sealed in a cool, dry, dark place to help preserve its labeled quality through the best-before date.

More specifically:

• Store your jar between 50 and 77 degrees Fahrenheit when you can, and keep it out of direct sunlight and away from a stove, oven, kettle, or sunny window. 

• Close the lid tightly after every use

• Keep water and moisture out.

• Use a clean, dry wooden or stainless steel spoon to scoop out each heaping spoonful. 

A pantry or closed cupboard usually works well for storage. (Refrigeration isn’t necessary and can make the honey firmer or encourage crystallization.) 

What Can Affect MGO Before the Best-Before Date?

Poor storage may impact your Manuka honey before its printed date; the date assumes you’ve handled and stored the jar correctly.

The main factors that may impact its freshness and quality include:

• Prolonged exposure to high temperatures

• Direct sunlight

• Significant temperature changes

• Moisture getting into the jar

• A loosely closed lid

• Contamination from wet or used utensils

• Repeatedly heating the whole jar

• Adding honey straight into boiling liquids

Laboratory research has shown that MGO may decline during storage at higher temperatures and after intense heating. With that said, one brief spell at normal room temperature won’t likely invalidate the MGO amount.

How Manukora Helps Readers Verify Their Jar

At Manukora, our labeling and batch traceability help you identify your product’s tested strength, source, and best-before information.

Every jar carries a clear MGO grade on the front label, a printed best-before date, and storage guidance, along with a QR code that you can scan to view your honey’s origin and beekeeper details. If your jar has been exposed to unusual conditions or kept beyond the date, our customer support team is here to help.

Overall, check the best-before date and batch details on your Manukora jar, store it tightly sealed in a cool, dry cupboard, and enjoy it within the labeled quality period.

FAQs

Is the MGO number guaranteed until the best-before date? 

The labeled grade is expected to remain accurate through the best-before date when the honey is stored as directed. For the exact quality-assurance wording, check your jar and our official product information.

Does MGO decrease as soon as the jar is opened?

Not simply because you’ve opened the lid. Proper sealing, temperature, light exposure, moisture, and handling are all more likely to impact MGO than simply opening your jar.

Can MGO increase while Manuka honey is stored?

It can. MGO may keep developing from remaining DHA during storage, especially earlier in the honey’s life. Over longer periods MGO can also gradually decline, and temperature influences both processes.

Does heat lower the MGO level?

Prolonged exposure to elevated temperatures can affect MGO and other components in Manuka honey. Store the jar in a cool place and avoid intense or repeated heating.

Is Manuka honey still usable after the best-before date?

It may still be enjoyable if it was stored properly and shows no signs of contamination. The labeled MGO grade shouldn’t automatically be assumed after the date, though.

Does crystallized Manuka honey have less MGO?

Crystallization alone doesn’t show that MGO has declined. It’s actually a normal texture change in raw honey, which doesn’t impact quality.

Sources

Studies on the formation of methylglyoxal from dihydroxyacetone in Manuka (Leptospermum scoparium) honey - ScienceDirect 

The Antibacterial Activity of Australian Leptospermum Honey Correlates with Methylglyoxal Levels - PMC