From America's Test Kitchen: Chefs are obsessed with emulsions because they combine something that is already delicious - unctuous fat - with a water-based ingredient to create something even more satisfying (think mayonnaise, butter, and cream—all emulsions). And egg yolks are one of nature’s top-notch emulsions—a creamy mixture of water, protein, and fat (a full 34 percent!). We love a good runny egg yolk and this recipe gives us the convenience of pasteurized, perfectly thickened yolks always ready to drizzle on toast, a burger, pasta carbonara, you name it.

Directions

1. Use a sous vide device to heat water bath to 149F.
2. Using spatula or ladle, push yolks through fine-mesh strainer into medium bowl; gently whisk yolks and salt until just smooth (do not overwhisk). Pour mixture into 1-quart double-zipper zipper-lock bag; seal zipper, leaving 1/4" opening on one end. Holding bag near opening, allow bag to lie flat on counter so that egg mixture fills bag and pushes air out opening. Seal bag fully.
3. Gently lower bag into water bath, allowing any remaining air bubbles to rise to top of bag (do not let go of bag). Reopen one corner of zipper, release remaining air pocket, and seal bag fully. Release bag into water bath and cook for 32 minutes.
4. Meanwhile, combine ice and water in large bowl; set aside.
5. Remove bag from water bath and immediately transfer to ice bath; let chill until cold to touch, at least 10 minutes. Transfer sauce to airtight container or squeeze bottle and refrigerate until ready to use.

Farm Team Tips

This recipe is easiest to do when using a sous vide device—either a self-contained insulated box called a water oven or a stick-style water circulator along with a pot of your choice.

This recipe safely achieves pasteurization (144F for at least 6 minutes) and then continues to heat the yolks to create a sauce with the ideal texture. The cooking time depends on the number of yolks, so this recipe cannot be scaled up or down without making adjustments.

Don’t discard the whites—save them to make angel food cake or meringue cookies or freeze them for later.

This sauce can be refrigerated for up to one week.