I have been testing this variable as I went along, comparing 180C and 200C with each batch. Every time, it seemed that 200C made the choux puff up more dramatically, resulting in bigger puffs but also ones that looked a bit messier precisely because they’d expanded to rapidly. Now it was time to just test temperature and to brave an attempt at baking at 160C, which had always ended in disaster. This test would be the ultimate answer … or so I thought.
I made one large batch of what is now my standard recipe – Buttery Cake Flour. I used a star nozzle because, well, it seemed like fun. And I made three trays to bake at 200C, 180C and 160C. The results are surprising. First, 160C was not a disaster. Colour me shocked. It was fine. Not such big puffs, but fine. Second, 180C and 200C this time resulted in nearly the same outcome. As you can see above, 200C led to only a little more puffing up than both, and 180C more puffed than 160C.
When cut, you can see they are all pretty hollow. The main difference is that the walls of the 200C ones are thinner than 180C and then 160C are perhaps a little thicker than both. It’s not completely obvious from the photo, but they were a bit ‘clumsier’.
180C seems fine. 200C is safe and will produce nicely, easily puffed choux. 160C will probably yield less scruffy looking choux, but they probably won’t puff as much and will be thicker (and therefore less fragile). So it depends on what you want to achieve. Also, I think higher temperatures are more forgiving of imperfect paste, so it’s also about how confident you are that your paste is well-made.