@john.jcb I just checked this and I think that the recipe might have been updated since your OP because in step 2, the recipe says: "Place each yolk in its own small zipper lock bag." Good call either way and thanks for checking!
Thanks for posting this comment @john.jcb If you’ve made yolks this way, what is the texture of the egg yolks?
Seeing this recipe has just given me an idea. Whole eggs are difficult to get right because of the different ideal temps of the yolks and whites. I am curious now what the perfect temperature would be to get a perfect texture on egg white. I am envisioning using two different temperatures of water bath with one at 143 F / 62 C for the egg yolks (assuming that yields the texture I want) and another temp for the egg whites. When the cooking is complete for both parts they could be served together as an ideal sunny side up eggs. The only problem I see would be figuring out how to get a presentable shape for the egg whites. Maybe float them on top of the water bath in ramekins or mason jars or something?
This weekend I am going to play around with eggs in a bag.
If this works out it sure seems easier to make poached and soft boiled eggs in a small Ziploc.
Hard boiled for all except deviled eggs would also work out well.