Mix formula with water above 70 °C, let it cool before feeding, and throw away what is left

Formula is not sterile. It can carry a bacterium that kills 4 in 10 to 8 in 10 of the newborns who catch it. Pour the hot water in first, wait until it falls to about 73.8 °C, then add the powder. In most cases that can kill this bacterium down to below 1/100000 of what it was. Hot water leaves a bit less vitamin C, but the formulas that were measured still met the standard. Let it cool after mixing, then feed. Throw away what is left.

Cost

No money. Each time, wait a few extra minutes for the milk to cool. The hard part is that when the child is hungry and crying, you still wait for the water to cool before you mix.

Benefit

Formula is not sterile. It can carry Cronobacter (阪崎克罗诺杆菌). The reported death rate after a newborn is infected is 40% to 80%. Experimental work shows: pour the hot water into the bottle first, wait until the water falls to about 73.8 °C, then add the powder, and in the great majority of cases the milk is still above 70 °C. That can cut this bacterium by 5 or more orders of magnitude, down to below 1/100000 of what it was. The price of hot water shows up in vitamin C. The World Health Organization and the UN Food and Agriculture Organization held an expert meeting in 2006. The figures seen at that meeting were: when formula is mixed with boiling water, only vitamin C falls clearly, by 5.6% to 65.6% across 4 formulas. Formula leaves the factory with extra vitamin C already added. The formula that lost the most still had 9.0 milligrams per 100 kilocalories after mixing, above the Codex Alimentarius floor of 8 milligrams. The meeting saw only this 1 study, so it drew no conclusion on it.

Notes

Disputed. The 2022 opinion of the German Federal Institute for Risk Assessment is that a healthy full-term baby can be mixed with water at 20 to 50 °C. It notes that most manufacturers also print 40 to 50 °C on the tin. Its reason is that 70 °C water cools quickly after it is in the bottle, so the kill is not as large as the calculation. Hot water also loses some nutrients, and feeding before it has cooled can burn the child. The European Society for Paediatric Gastroenterology, Hepatology and Nutrition, in 2004, also did not favor mixing with boiling water, worrying that it would damage vitamins and the probiotics added to the formula. The World Health Organization and the UN Food and Agriculture Organization still recommend above 70 °C. The highest risk is for babies born early, babies with a birth weight under 2500 grams, babies under 2 months, and babies with weak immunity. Mix those at 70 °C, or ask a doctor. For a healthy full-term baby mixed at the temperature on the tin, this German opinion considers the infection risk extremely low. The 70 °C threshold comes from public-health guidance. Beary and colleagues' own words were: "public-health guidance for caregivers of high-risk infants recommends reconstituting formula with water heated to at least 70 °C (158 °F) to inactivate microorganisms." Do not mix with water that has sat in a thermos for 1 day. Do not leave mixed milk at room temperature for the next feed.

Sources · 7

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