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I found this recipe which features Italian meringue as topping. After preparation, the meringue is not cooked further, yet the author claims that adding the sugar syrup alones has pasteurized (i.e. killed all germs) the eggs. Can this really be assumed?

The basic steps in this recipe in this regard are:

  1. Beat 100g of egg whites until stiff
  2. Add 200g of sugar, dissolved in 30g of water and heated to 120°C

Assuming that the 100g of egg is at room temperature, or slightly cooler, then the mixture would probably exceed 70°C, but I am concerned that the time it would be this hot would be long enough to actually consider the final product pasteurized.

Glorfindel
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FlyingTeller
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4 Answers4

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For the pasteurization of egg whites, the time required is at most 48 seconds at 140 F (60 C). (Source: FSIS, table on page 39)

This means that you can easily use the method to know if you've pasteurized the egg whites. Simply keep the thermometer in the bowl while beating your meringue. If it takes more than 48 seconds to fall under 60 C, you've pasteurized them. And if you should find out that it fails too often, you can change your setup - e.g. start beating the meringue over a water bath - to ensure you reach the required duration. In practice, I think that it would be difficult for you to make a meringue that cools down in less than 48 seconds.

Note that this requirement is for egg whites specifically! The times for whole eggs and egg yolks is given in the same source, in a chart on page 17, and they need more time for pasteurization.

Glorfindel
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rumtscho
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I would not consider this "pasteurization," which has a specific meaning in food science, but the method of "cooking" sugar to around 240°F or 116°C and threading it into an egg foam is an accepted and proved method of ensuring the food safety in your meringue. You do not need to check the temperature, but you can feel the mixing bowl (especially if it's metal) and you'll get an idea of how hot it is and how long it takes to cool to room temp.

As a side note, I would not employ the method you state exactly. I find it's best to use about 1/3 of the sugar uncooked and add it to the eggs (French meringue-style) after it has reached soft peaks (or at least a decent foam, depending on your sugar grain size) and then beat the whites to a a medium peak before threading in your sugar. There are many methods that work well, so if the recipe you're following works for you then that's great as well.

You can also add an acid (like cream of tartar) to the whites before beating them which helps prevent the proteins from bonding too tightly and also helps the foam form.

If you're very concerned with food safety another method you can use is the Swiss method where you cook the egg whites and sugar over a double-boiler first (to 160°F or 70°C) and then beat them in your stand mixer with the whisk. I prefer the Italian method, but this works well and is easier to do.

myklbykl
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Jurisdiction disclaimer: If you are in the US raw egg whites are not considered food save and may not be served in a commercial setting. Whether you want to personally take the risk is up to you.

If you are in Europe, raw beaten egg whites are used in some recipes and are considered food save. A common example is a mousse au chocolat. Of course one should only do that with very fresh eggs from a reputable source and possibly avoid recipes like that if you are in a risk group like being pregnant.

I don't know whether the difference is due to the US having stricter standards on food safety or due to Europe have stricter standards on producing and selling eggs. If you are somewhere else in the world, check your local health authorities.

quarague
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Harmful microbes are not your only concern. Raw egg whites contain protein named avidin, which is an antinutrient that severely interferes with vitamin B7 absorption. Prolonged consumption could cause vitamin B7 deficiency. Avidin is quite heat resistant and remains stable below 70 °C. Just mixing raw egg whites with melted sugar is not going to destroy that protein.

More from Wikipedia:

A 1991 assay for the Journal of Food Science detected substantial avidin activity in cooked egg white: "mean residual avidin activity in fried, poached and boiled (2 min) egg white was 33, 71 and 40% of the activity in raw egg white." The assay surmised that cooking times were not sufficient to adequately heat all cold spot areas within the egg white. Complete inactivation of avidin's biotin binding capacity required boiling for over 4 minutes.

user108249
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