Why Heat Treat Flour?

You might be tempted to snack on the uncooked cookie dough when cooking cookies at home. However, if you’re making your own cookie dough from scratch, you might want to think twice before eating it uncooked. It may make you feel ill!

At Dough Dreamery, we are aware of how alluring it is to nibble on that delicious raw cookie dough. However, the common components you keep in your kitchen cupboard might not be suitable for consumption without being baked. For this reason, if you wish to consume the cookie dough raw, you must get it from us.

Without needing to bake it into cookies, we make cookie dough that is suitable for consumption. Even while you can bake using our cookie dough if you want to, you are not required to. Heat-treated flour is one of the elements we utilize to make our dough safe, which you probably don’t have at home.

E. coli bacteria can be found in regular flour that has not been heat-treated. When batches of flour are recalled due to illness, you’ve probably heard about it in the news or on the internet. That is contaminated flour, which is why it is dangerous to consume it uncooked (even when it is combined with cookie dough) if it has not been specifically treated to get rid of those harmful bacteria. While eliminating the harmful microorganisms, heat treatment maintains the flour viable for use in cookie dough. The uncooked flour is thoroughly roasted at high temperatures to ensure that any harmful microorganisms are eliminated. We utilize flour that has been heat-treated commercially at Dough Dreamery. This guarantees that the heating procedure was carried out accurately and thoroughly, allowing you to feel secure eating it when it is combined with unbaked raw cookie dough.

When it comes to consuming raw cookie dough, heat-treated flour and pasteurized eggs are crucial! We refer to our dough as “edible cookie dough” to allay any concerns. Feel free to indulge! Visit our Parker store right away to get that sweet treat you’ve been craving!

Does flour need to be heat treated?

For any dish that will be baked or cooked on the stovetop, flour does not need to be heat-treated.

You don’t need to heat treat your flour, for instance, if you’re creating cake batter that will be cooked at 350 F / 175 C before being consumed.

If you are cooking a dish that calls for flour but won’t be cooked or heated, you do need to heat treat your flour.

What is Heat Treated Flour?

The ideal temperature range for heat-treated flour is 210F to 230F, which has been cooked for 60 minutes. 1 It can:

  • Increase shelf life
  • increase cake production
  • Produce finished goods with a fine, uniform grain.
  • 6

The ability of heat-treated flour to absorb moisture and the inability of its protein content to produce gluten when the flour is hydrated are its distinguishing qualities. It is most frequently used with baked items with a high ratio.


The heat treatment is done to prevent microorganisms from growing during the flour’s shelf life. Most shoppers are unaware that flour is a raw ingredient. The ingestion of raw dough was linked to an E. coli outbreak that affected 64 persons and spread to 24 states. 6 Prior to employing heat to cure flour, transportation and preservation of flour were challenging since it would spoil quickly.

There is a safer method of treating flour than chlorination and irradiation, which was first patented in 1970.

2 Because it gives flour more softness and makes it more palatable, the capacity of heat-treated flour to absorb moisture is appreciated in food. 2


According to research, the protein content of heat-treated flour may be more easily digestible than that of raw flour. 3 The heating procedure results in an improvement in palatability. 2 The body needs vitamins, proteins, fiber, and other complex carbs for daily function, all of which are abundant in flour.

Commercial Production

There are several procedures involved in producing heat-treated flour for commercial use. 5

  • Until the moisture level is low, flour is thermally dehydrated.
  • The heated flour is allowed to cool to room temperature.
  • The moisture content is preserved by heating the dehydrated flour once more.

The proteins are denatured and moisture absorption is boosted by starch gelatinization as a result of these heating processes. 7


With high ratio baked items like cakes, cookies, and muffins, heat treated flour works well. When flour is heated, starch granules become gelatinized, which increases their ability to absorb water. 7 Starch granules swell when they come into contact with water, thickening the batter and stabilizing the baking process. Heat-treated flour produces baked items with better texture, volume, and height.

When utilizing heat treated flour, breads and other yeasted items do not rise or develop as well because of the weaker protein structure.

FDA Regulation

FDA regulations regulating heat-treated flour are not yet in place. The FDA advises against consuming uncooked dough items prepared with any brand of flour or baking mix, though. When handling flour, consumers should always use safe food handling and preparation techniques. 6

Why should flour be microwaved?

Cooks have long been aware that licking the spoon after preparing cake batter or sneaking a piece of cookie dough puts them at danger of getting salmonella from raw eggs. Recently, some people have even heard that raw flour can make them sick, leading to advice to sterilize flour before mixing by heating it in the microwave or in the oven.

Yaohua “Betty Feng, a food scientist at Purdue University, contends that this knowledge has created a false sense of security because there is no guarantee that these treatments can completely get rid of any foodborne viruses that might be present in the flour. Salmonella and E. coli can be killed by heating meats and other wet items to specific temperatures, but they behave differently when exposed to dry components like wheat.

Salmonella in chicken is killed by cooking it to 165 degrees, according to Feng. But because Salmonella is more heat resistant when moisture levels are low, it’s not that easy with flour. To confirm how hot the flour would have to be or how long you’d have to hold it at that temperature to make the flour safe to eat, we still need more research data.

Some cooks are taken aback to see labels on flour sacks cautioning against consuming the product raw. After wheat is milled, packaged, and delivered to grocery stores, it is sold as raw flour.

To eliminate any potential foodborne bacteria, several chefs and food bloggers advise either microwaving flour or spreading it out on a baking pan and baking it in the oven. Some even provide precise temperature goals, which are typically 165 degrees. Feng cautions that there are no assurances that flour that has undergone those unproven heat treatments is safe to eat.

A raw component that may be a foodborne disease carrier is flour. There is no proof that heat-treating flour in an oven or microwave, as many food blogs advise, eliminates these pathogens, even if proper cooking can get rid of dangerous microorganisms.

Heat transfer can be impacted by the sort of container you use, how the flour is mounded, and other variables, according to Feng. ” Although it may seem like being cautious to heat your flour, those techniques are not supported by science.

In a research Feng conducted to examine consumer understanding, 66 percent of flour consumers confessed eating uncooked dough or cake batter; 85 percent of consumers were not aware of recalls or outbreaks involving flour; and just 17 percent thought they would be negatively impacted by such events.

Overall, consumers have very little knowledge of flour as a raw material. More education and communication are required, according to Feng.

Feng is a member of the team of the Michigan State University-based Center for Low-Moisture Food Safety, which deals with issues related to the microbiological food safety of low-moisture commodities like wheat flour. The center, which carries out research to assist customers in making educated decisions, is funded by the United States Department of Agriculture.

But until further information is available, Feng advises baking all that batter and dough and restraining yourself from licking the spoon.

What does it mean when flour is heat treated?

It is first vital to comprehend why you shouldn’t consume raw flour in order to comprehend why you should heat-treat flour. Wheat kernels are exposed to salmonella and E. coli germs while they are growing outside. Before being made into flour, wheat kernels are washed and sifted, but the bacteria isn’t totally eliminated.

By heating the flour, the harmful germs are eliminated, allowing it to be utilized in a variety of recipes, including no-bake sweets.

Fortunately, heating flour is a simple process. The simplest method is to microwave flour in a bowl on high until it reaches 165 degrees. The flour can be heated in the oven as a second alternative. For this method, preheat the oven to 300 degrees, spread the flour over a baking sheet, and bake it for two minutes at a time, checking the temperature after each two minutes, until it reaches 165 degrees.

Is it safe to eat raw flour?

  • The majority of flours used in baking and cooking at home are created directly from uncooked grains.
  • Creating flour from raw grains does not eradicate dangerous microorganisms.
  • Numerous items prepared with flour also include raw eggs, which could be contaminated with dangerous pathogens.
  • The only method to guarantee the safety of foods produced with wheat and raw eggs is to cook them.
  • Never consume or taste uncooked dough, batter, or flour.


Since 2009, there have been a number of outbreaks of foodborne disease involving raw flour or foods like cake mixes and cookie dough that contain raw flour. 20 hospitalizations and 168 known diseases as a result of them.

How long should flour be heat treated?

  • 350°F oven temperature.
  • Spread a thin coating of flour on a cookie sheet after covering it with parchment paper (or the exact amount you need for your recipe).
  • Use a food thermometer to verify the temperature of the flour after baking it for about 5 minutes. It need to say 160 degrees. Give it a minute more if it isn’t quite heated enough, then check again.

Does heat treatment of gluten-free flour become necessary?

The gluten-free flour is heated to help kill any bacteria and make the cookie dough safe to eat. To heat treat flour, there are two techniques.

The gluten-free flour is heated in the microwave for one minute, or until it reaches 165°F, in the microwave technique.

I check the temperature of the flour using an instant-read thermometer to make sure it reaches 165F. I like using a microwave.

How can raw flour be made safe to consume?

Follow these steps to confirm that raw flour is safe to consume or taste: It’s as easy as this: to destroy the germs, raw flour must be cooked to at least 165 F (74 C). Both the oven and the microwave can be used to heat-treat the flour.

Can you heat treat flour in a microwave?

Using your oven or microwave to bake flour is simple. So that you have some on hand for when you want to consume raw cookie dough, go ahead and start a batch now.

When using flour in oven- or stovetop-baking or cooking recipes, there is no need to heat treat the flour.

Heat Treat Flour in the Oven

Because you can produce more heat-treated flour at once using a baking sheet, this method is the most practical.

  • the oven to 300 degrees.
  • On a baking sheet with a rim, distribute 2 to 3 cups of flour. If you’d like, you can line the pan with Silpat or parchment paper to prevent the flour from sticking.
  • Bake in increments of two minutes, stirring and rearranging the flour between each. Continue doing this until the flour reaches 165 degrees.
  • Flour should be taken out of the hot pan and placed in a fresh bowl. Use none of the flour that has become on to the pan.

Heat Treat Flour in the Microwave

The quickest and simplest approach to produce tiny quantities of heat-treated flour is using a microwave. When it’s hot outside and you don’t want to heat up the kitchen, this is a terrific option.

  • In a heat-safe bowl, add half to one cup of all-purpose flour.
  • 30 second intervals in the microwave, stirring after each one to prevent “hot” patches.
  • Every microwave works differently, so the time it takes to reach 165 degrees can vary. Check the temperature using a food thermometer at regular intervals.
  • Avoid overheating the flour to prevent it from becoming lumpy and brown. Brown flour can still be used, but it will taste like it has been roasted.

How frequently is E. coli found in flour?

The German Federal Institute for Risk Assessment (BfR) released a comprehensive paper early in 2020 on the causes, dangers, and mitigation of pathogenic E. coli in flour (and products containing raw flour). According to a survey conducted in Germany, between 10% and 30% of flour samples tested contained Shiga Toxin Producing E. coli (STEC), a virus that can lead to widespread outbreaks of serious illness.

Products containing raw flour that are not thoroughly boiled before consumption are clearly the sources of the dangers. Raw doughs, cake, and cookie mix are among examples. These threats are not hypothetical. A STEC outbreak connected to uncooked flour in the USA in 2019 impacted 21 people, while a flour-related outbreak in 2016 affected 63 people and resulted in 17 hospitalizations and one person developing a severe kidney illness.

The BfR report states that these organisms can survive in flour stored under ambient temperatures for at least nine months in addition to their high prevalence in recently manufactured flour. This period is shorter at high temperatures but lengthens as the temperature drops below ambient.

Some food producers have changed to utilizing heat-treated flour in goods that might not be fully cooked before consumption in response to this concern (e.g. cookie doughs, or products using dusting flour). However, the data demonstrates that in the low water activity conditions of flour, STEC’s heat resistance increases. The D values, or the time required to reduce cell populations by a factor of 10, were reported as ranging from 5.75 to 18.2 minutes at 70C for wheat flour with a water activity of 0.45. This indicates that the organisms in the wheat flour are far more heat resistant than the same organisms under conditions of high water activity, when a reduction of the same magnitude would take place in about 20 seconds.

The paper lists many proposed safeguards that might reduce the hazards to food safety. These are predicated on the understanding that flour is a raw material that might be contaminated with microorganisms. The controls consist of:

  • separating flour from prepared meals
  • using different tools for flour processes
  • washing hands after handling flour, and
  • avoiding eating unbaked goods

The paper also emphasizes that cooking at 70C for two minutes is adequate to kill these organisms in wet items (such as doughs) (a six log reduction). STEC are not eliminated from dry flour at a temperature of 70C unless lengthy processing durations are employed.

Microbiological risk assessment and heat process validation are services provided by Campden BRI. For accredited STEC testing, get in touch with Campden BRI or go to www.campdenbri.co.uk.

Fellow Roy Betts works for Campden BRI, a UK-based independent worldwide food consultancy and research organization. His responsibility is to keep the industry fully informed about all microbiological issues and to assist businesses in responding to and managing microbiological problems that affect them and their goods. Roy oversaw a sizable microbiology division at Campden BRI prior to embarking on this position. His areas of expertise included test method development and validation as well as incident and crisis management. In the field of food microbiology, Roy has published widely and serves on a number of committees.