Flash heating

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How to flash-heat

Below is a transcript from this explanation:

  • “Always wash all utensils that you will use to express and heat treat your breast milk with clean water and soap. It is best to boil these utensils after washing to make sure that they are clean.
  • Put all the milk you have expressed in a heat resistant glass (not plastic) jar. The amount of milk should be between 50 ml and 150 ml. If you have more milk, you may divide it into 2 jars.
  • Place the jar of milk in a small pan of water. Make sure the water is about two fingers above the level of milk so that all the milk will be heated well.
  • Heat the water on a very hot fire or on the highest levelof your stove until it reaches a rolling boil (when the water has large bubbles). Stay close by because this should only take a few minutes. Leaving the water to boil too long will damage some of the nutrients in the milk.
  • Remove the jar of milk from the boiling water immediately after the water comes to a boil. Place the jar in a container of cool water, or let it stand alone to cool until it reaches room temperature.
  • Protect the milk as it cools and during storage by placing a clean lid or small plate on it.
  • You can safely feed your baby this heated milk within 6 hours.
  • Always feed the baby using a clean open cup. Even a newborn baby learns quickly how to drink from a cup. Avoid using bottles and nipples. They are difficult to clean and may make your baby sick.”1

A simple how-to explanation can also be found here.

For a visual on how flash-heating can work at home, please watch this video from UC Berkeley School of Public Health.

Flash heat and HIV
Given the specific risks for lactating parents in developing country settings, research studies focused on determining the impact of flash-heat on HIV, bacteria and breast milk’s protective elements, such as immunoglobulins, vitamins and the immunoreactive proteins lactoferrin and lysozyme. Studies by a research team lead by Israel-Ballard,2 have shown that FH breastmilk inactivates HIV and 4 common bacteria while retaining high levels of vitamins, lactoferrin,3 and immunoglobulin,4 which are important for the health of a baby and its immunity to infections. See ‘Why breastmilk’ for more information on the importance of the anti-infective components of breastmilk.

Safety of flash-heating
When researchers designed the flash-heat method for lactating parents in developing countries, it was an attempt to replicate the flash-pasteurization methodology for a low resource setting. Flash-heating is a simplified in-home process and as such is not as controlled as the actual flash pasteurization method. Altitude, breast milk volumes, water volumes and human error could contribute to differences in the flash-heat process. Although researchers hypothesize that the temperatures achieved during flash-heat render it safe, it should be noted that its effectiveness to inactive all viruses and spores5 has not been thoroughly researched. Please see the section ‘Flash heating vs. Flash-pasteurizing’ for more information.

When heat-treating breastmilk, especially when using the Holder Method, many important anti-infective factors are reduced. Also, lipase, an enzyme that helps with the break-down and absorption of fats, is significantly reduced by flash-heating and deactivated by Holder pasteurizing. Please also see ‘What about premature babies?’ for information about the effect of heat-treating on some important components of breastmilk. Wet-nursing and/or raw, fresh (not frozen) when possible, screened and properly handled breastmilk is a better option when available.


  1. For more information on cup feeding, please see ‘How do I feed the milk to my baby?’ []
  2. –‘Heat Treatment of Expressed Breast Milk Is a Feasible Option for Feeding HIV-Exposed, Uninfected Children after 6 Months of Age in Rural Zimbabwe’
    –‘Flash-Heat Inactivation of HIV-1 in Human Milk’
    –‘Inactivation of Cell-Associated and Cell-Free HIV-1 by Flash-Heat Treatment of Breast Milk’ []
  3. Lactoferrin is a round multifunctional protein with antimicrobial activity (bacteriocide, fungicide) and is part of the innate defense, mainly at mucoses. Lactoferrin is found in milk and many mucosal secretions such as tears and saliva. []
  4. Immunoglobulins are a class of proteins produced in lymph tissue in vertebrates and that function as antibodies in the immune response. []
  5. Please see ‘Bacteria’ for more information. []

2 Responses to Flash heating

  1. DadyAlicia89 says:

    I am very confused at to what I could have possibly gone wrong. I followed these steps exactly as written. When it started to boil I took it out. The bottom broke off and I lost all of my donor milk into the water. Have there been other issues with this method?

    • admin says:

      Did you use a heat resistant glass? Most baby bottles are most likely not.

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