Kah22.  You didn't divulge what fat Sainsbury's used in their rough puff pastry!

I think a lot of commercial puff pastry uses margarine or shortening.

The one and only time I made puff pastry was in school, and we used half butter, half Cookeen, which is a hard vegetable shortening like Trex or Crisco. I don't know if they were saving money or if the harder fat gave a better texture. I know shortcrust is better made with lard or shortening than with butter.

My grandmother used to make the pastry with lard .. Or sometimes half lard and half. Margarine . My mother also used to make pastry like that . Neither would have dreamt of using butter in pastry .

Me .. I just like the flavour of butter in baking .

Sorry I always still think of margarine as the blocks of hard margarine.
I always think of the soft stuff in tubs as 'spread' .

That's interesting what you say about the president butter , I had not realised that .
I have some in the fridge at the moment but its the spreadable pot rather than the block. I have not tried it yet .

hmm,

There are mainly 2 reasons that the industry mostly don't use butter in puff pastry (unless the package says so to add value of course):
- Milk fat is expensive: more expensive than most fats from vegetable origin.
- Milk fat is not the ideal fat for making puff pastry: Although there are a few techniques for making puff pastry it all comes down to this: between the various dough layers there is a very thin layer of fat. This fat keeps the various layers of dough 'apart' enabling a nice puffing during baking. So what you want is NOT TO BREAK this very thin fat layer. Butter 'breaks' / spreads easily uneven while making puff pastry dough. Therefore the best fat for industrial puff pastry is actually quite hard and kneadable. It doesnt feel fatty and it's texture is well... more like clay. With this fat you can make very thin WHOLE layers of fat between the dough layers.