Puff pastry for my lamb Wellington didn’t puff up

Wrapped the pastry around some sous vide medium rare lamb steaks, with leek and mushrooms stuffing, brushed with egg wash and baked it at 500 for 10-12 minutes. The pastry ended up flat, and greasy and barely brown. Decoration on top did brown.

Mary Lindquist


702551 October 18, 2021
When puff dough doesn't puff up but gets greasy or starts leaking butter it means the dough was too warm, either by being left out at room temperature too long or overhandling (or both).

I don't know what recipe was followed here but usually one doesn't want to wrap raw puff dough around a warm object. That melts all of the butter in the puff dough layers which would explain the OP's unfortunate outcome.

Butter melts at 90–95 °F (32–35 °C).

In fact, some beef Wellington recipes instruct to chill the (raw) meat in the freezer for a short time to make sure it is extra cold to start.
Nancy October 17, 2021
Mary Lindquist...not sure why the pastry didn't rise. A few questions or possible problems occure to me:
was the leek and mushroom stuffing very wet?
was the pastry commercial and thawed completely?
a brand new to you?
or handled too much before baking?
was the oven heated before putting the lamb wellington in?
Have a look at articles like this one for troubleshooting.
was the oven too hot (many recipes calls for 400F)?
Mary L. October 18, 2021
Thank you. Familiar brand. But maybe too much handling before and recipe I based it on called for 500 degree oven. Thank for reference to bakingneeds. Will check it out.
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