A Del-Val Food Ingredients Brand

Donut Glaze Technical Information

Donut and Sweet Goods Glazes and Icings

Key Blends brand donut glaze stabilizers are a premium brand of icing and glaze stabilizers available in two highly concentrated versions of glaze stabilizer concentrates.

Key Blends only uses the highest grades of gracilaria agar that has the highest water binding and gel strength. Agar is the most expensive ingredient in the stabilizer and there are several grades of agar. We only use agar coming from the gracilaria sp. seaweed as it is highly functional in glazes due to its high water-binding ability. It is vital to use a stabilizer with the correct agar type and grade to achieve proper water binding characteristics.


Please contact us at 856-778-6623 or This email address is being protected from spambots. You need JavaScript enabled to view it.  for samples and a trial run of Key Blends Donut Glaze Stabilizer.

How to Make Donut Glazes and Icings.

Icing and glazes for sweet goods and donuts are water icings that are nonaerated and consist of mostly sugar and water. Typically, glazes are used on yeast-raised donuts and honey buns where icings are used on pastries, Danish, honey buns, cake donuts, and yeast-raised donuts.

For icings, the water content is 12 to 15% and the sugar content is 82-85%. The icings will be more viscous and are applied to the top surface only. Icings are usually whiter in color. The lower water content and the fact that it is applied on a cooled baked good allows for a reduced syneresis of the icing.

For glazes, the water content is 20-25% and the sugar content is 70-75%. This will make a less viscous product that will flow over the entire product almost enrobing the donut. The final glaze will be slightly clear. Glazes are usually applied on hot donuts and glazes have more syneresis and other breakdown issues on shelf life.

The icing or glaze system is a two-phase system consisting of small sugar crystals dispersed in a saturated sugar solution stabilized with our stabilizer. The key to making a successful glaze or icing is to develop a product which contains the minimum amount of syrup. Therefore, maintaining the quality of a glaze or icing is dependent on controlling the syrup in the system.

The worst mistake is adding water to the glaze to thin it down. Never add water to thin down a donut glaze or icing.



Donut Glaze and Icing Ingredients

Sugars in glazes and icings

Stability of donut glazes and icings is dependent on maintaining a constant sugar crystal to syrup ratio during shelf life. Changes of more syrup during shelf life results in increased syneresis. Loss of moisture will result in cracking and chipping of the icing. Moisture loss from the glaze or icing is the result of osmotic pressure of the lower water activity glaze or icing pulling moisture from the higher water activity dough. This will cause substantial drying of the crumb and potential breakdown of the glaze or icing.

Maintaining the syrup to sugar ratio in the glaze or icing is critical in maintaining a satisfactory product over shelf life.

Granulated sugar is used in the boiling phase (syrup phase) of the process. This sugar is important for several reasons. First, the sugar will raise the boiling point of the syrup allowing a hotter glaze or icing to be made. Hotter glazes can will have lower water levels due to decreased glaze viscosity.  Lower water levels will result in more stable crystals being formed.  In addition, this hot syrup will create a supersaturated sugar solution upon cooling which will help maintain the sugar solids to syrup ratio. 

Powdered sugar usually 6x sugar is used for the fine sugar crystal phase.

Humectants such as corn syrup or invert sugar can absorb water and help prevent evaporation from the donut icing or glaze to a very limited extent. However, they can also create sticky glazes and icings and will retard drying. Melting of the glaze or icing can occur during shelf life. Humectants are used to a very limited degree usually used to help improve shine and limit cracking. Typical levels are 0-4% of the powdered sugar content in icings and glazes.

Water in glazes and icings

The amount of water in an icing or glaze is usually the controlling factor in the stability of the glaze or icing. It is very important to limit the amount of water.

Even a small amount of extra water in the syrup can have significant increases in glaze breakdown.  Increasing the application temperature is the preferred way of decreasing glaze viscosity up to a temperature of 145F.  Glaze and Icing application temperatures above this can result in severe grittiness of the glaze or icing.

Glazes and icings with higher water content are thinner and are easier to apply. This is especially true for donut glazes. Using higher water levels will result in significantly more glaze breakdown. A better way would be to add more granulated sugar to the syrup to increase the glazing temperature. Higher glaze and icing temperatures will result in thinner easier to apply glazes and icings.

Shortening in Glazes and Icings

Two types of fats are typical in glazes and icings: Hard fat flakes with a melting point of 120F and higher and standard bakery shortenings with melting points of 110-120F.

Shortenings help speed up drying rates of glazes and icings and they can provide some stability. Fat can also help maintain the sugar to syrup ratio of the glaze by making fat barriers that prevent sugar and syrups from migrating. Shortening also assists with helping the icing or glaze adhere to the baked good.

Levels vary with climate and packaging types. In the past levels of 1% to 4% or the powder, sugar levels were typical. We have seen improved packaged glaze stability for levels up to 10%. Higher levels are useful in items to be frozen. Higher levels of fat will require the use of lower melting point fats to prevent chipping of the glazes and icings. Lower melting point fats can add creaminess to the glaze or icing.

However, excess levels of hard fat flakes can produce brittle icings and glazes that can chip and flake and can set too fast and can be waxy. In packaged donuts, the fault level is well above 10% fat.

Soybean oil is occasionally used at low levels to improve gloss.

Emulsifiers in Glazes and Icings

Emulsifiers such as high melting point monoglycerides can be added to the boil phase at 1/2% of powder sugar to help bind water by creating an emulsion of bound water. Excess levels can cause a dull glaze.  Emulsifiers are critical in higher fat icings and glazes to prevent separation of the oil and water.



Processing Donut Glazes and Icings

The process of making glazes and icings is a 2 or better yet a 3 stage process.

The first stage is the boiling of the stabilizer.
The agar MUST be boiled to fully hydrate the gum. This must be done if you wish to have a stable glaze or icing.

The water and the stabilizer is added to the steam kettle and this is brought to a rolling boil for 3 minutes. Enough time and temperature is needed to fully

hydrate the agar to gain full functionality. Do not skimp on this stage.  Exact boil time is critical as well as the boiling phase reduces the water due to evaporation.  Consistent glazes and Icings need consistent boiling times.

The second stage is to add the sugar to the boil and reboil. Sugar will compete with the agar during the hydration stage. That is the reason why you should do this in 2 steps. Many do this in a single step, but the results are not as consistent. Bring the syrup to a boil a second time for 1 minutes and add the hard fat, shortening, and emulsifiers.

The syrup should then be mixed with the powdered sugar. The process for a liquifier vs. a vertical mixer is slightly different.

Vertical mixer- slowly add syrup over 2 to 3 stages to prevent lumps.

Liquidifier- add all powdered sugar and allow the high shear machine smooth out glaze.


Apply glazes and icings at 135F to 145F. This recommendation is much higher than those of the past. Lower water levels are needed in the syrup phase at these temperatures and will allow the glaze to flow well and set fast. Our experience shows much better results with this higher glaze and icing application temperatures. Do not allow the temperatures to exceed 150F. Severe crystallization will occur at 150F.  This will create a very gritty unstable glaze.

Avoid thinning glazes and icing. If it must be done use simple syrup.  NEVER USE WATER. Water will upset the balance in the glaze or icing and water will destroy the stability.

If your production staff is using simple syrup on a regular basis, this indicates the batch size is too large. Remember, the syrup ratio is critical and constantly adding simple syrup to thin out the glaze is an indicator that the syrup to sugar ratio is changing too much.