I mentioned in last week’s post on the mechanics of, er…mechanical leavening that steam is the force responsible for the heavy lifting in laminated doughs. Steam of course comes from water, which means the more water in your laminated dough the better.
Or so one might be tempted to think. Lots of moisture in a laminated dough is in fact a bad thing, especially where the butter is concerned. It’s a common misconception that laminated doughs need the water content of butter (and indeed most American butter is about 18% water) in order to rise. The fact is that all the water a sheet of puff pastry is ever going to need is right there in the détrempe (a French word for “dough” or “mix”, the adjective version of which [détrempé] interestingly means “soaked” or “soggy”) .
The butter’s water content actually drags the dough down, working as it does to soften the dough sheets, causing them to stick together. This is why most French pastry makers employ specialty butter by the name of “beurre sec” (“dry butter” which is only about 12% water) to make their laminated doughs.
Sadly, beurre sec is almost impossible to come by here in the states unless it’s purchased from a commercial purveyor. That’s why, for reasons of both texture and flavor, you want to use a European (or European-style) butter when making a laminated dough. It won’t be as “dry” as beurre sec, but drier than most American butters, and the more moisture you can wring out of your process, the better.
Oh, and higher-fat butters also melt a bit more slowly than their more watery counterparts, a great advantage in laminated dough-rolling.