From N., 6 December 2009, Salt crusts for beef?
Q: I have a question for you about it actually! Have you got anything to say about salt/herb crusts on roasts?
A: Thanks for your question. I haven’t prepared the recipe you referenced [from the December/January 2009 issue of Fine Cooking] so I looked it up.
Although I haven’t prepared a salt crusted beef, the technique makes sense. Although it seems that the meat would steam inside the crust, it will not. Instead, the crust bakes into a dry, clay-like oven – a secondary hot oven, if you like. Your roast should not steam inside the crust, if executed correctly. Instead, because it is a smaller environment than the larger oven, it should provide a more even heat, and allow the meat to cook without risk of the hotspots in your oven. This promotes a moister roast.
Your roast should brown inside the crust. The Maillard reaction, which is responsible for browning and involves some complex reactions among amino acides, occurs most reliably at tempratures over 110C, in the absence of water. As long as the surface of your roast is dry and the salt crust is properly executed, the roast should brown even inside the crust as long as the oven is hot enough. Also, the recipe in question provides for searing before encasing it in the crust, so you should have a nicely browned roast. You will need a hammer to remove the crust, which always provides a little drama.
That said, the salt crust does have drawbacks. You’d think saltiness would be the principal drawback, but it isn’t – since the salt combines with flour to make the dough “oven,” it doesn’t really penetrate the meat that much. The main drawback is the fact that you will not be able to use any beef drippings for gravy or pan sauce, nor can you recover them for future use as cooking fat, for they will be inedibly salty. To me, this is a fatal flaw in the use of the salt crust – the beef tallow is nearly as precious as the roast, since I use it to fry potatoes. So if I were to make this dish, I would use a cut of meat that provides little in the way of drippings, like chateaubriand or beef tenderloin.
Another note about the recipe in Fine Cooking: I’m not sure the herbs, incorporated into the dough for the salt crust, will provide meaningful herb flavor to the roast. If I were preparing the roast from this recipe, I would marinate the roast in advance by mincing the specified herbs and combining with some crushed garlic cloves, ground black pepper, and some ground coriander seed. Marinate the beef in this mixture for a day if possible, turning to coat as necessary. When ready to roast, remove large chunks of herb and garlic and then wrap the meat as specified.