In this second part of my series of blog posts about duck I am going to go over my duck prosciutto-making project. This is a somewhat exact process that involves hanging uncooked poultry for more than a week so bear with me if veer towards the technical.
This preparation really is about process. The first step (after the duck breasts are removed from the body as discussed in my earlier post) is to fill a non-metal container with a bed of kosher or coarse salt. Lay the breasts on the salt, arranged so that they aren’t touching and cover with more salt. The container–covered with plastic wrap goes into the fridge for twenty-four hours of curing.
This step starts the process of pulling liquid from the meat and adds salt to it. On top of salt’s usefulness in enhancing our perception of flavours it also works as an anti-microbial agent. It has become a foodie cliche that salting meat and fish used to be used as a means of preserving it in the days before refrigeration. After the curing, the salt is rinsed off and the duck breasts are dried very thoroughly with paper towels.
Flavourful spices and herbs are sometime rubbed into the duck breasts before they are cured in the salt–especially when the ingredients are coarse ones like peppercorns, juniper berries, or bay leaves–but because I am using ground spices I added them to two of the duck breasts (the other two will be straight up) after the cure. To connect the flavours that traditionally go with duck to Christmas I am going to flavour this preparation with orange and ground cloves. Luckily, my excellent Spice Trader spice collection includes a container of orange peel powder. Orange zest could be used instead but probably should be added as a pre-cure flavouring and then rinsed off with the salt. Ground cloves are easy.
Each rinsed and dried duck breast was weighed and then wrapped in cheesecloth. Trussed like a roast I hung them in a basement cold room. This spaced varied in temperature between 5°C and 8°C and a relative humidity between 60% and 70%.
As the duck breasts hang they do acquire that smell particular to prosciutto. There are elements of sweetness and saltiness here but that doesn’t capture the whole idea. It’s not really funky either–and some foods like Stilton and sourdough starter are quite funky–but there is a trace of fat that has gone very slightly off.
The odor doesn’t pervade or overpower and I had to put my nose almost right up to the cheesecloth to smell it but it is very distinct and did get slightly stronger near the end of the ten day process. I imagine there are prosciutto afficianados in Parma who would bristle at the application of the name to salted and dried duck breasts but for the home producer the name is useful if only because I knew I was roughly on the right track when, by the fourth day, my project had acquired the recognisable prosciutto smell.
So, how did I know when it was ready? Well, that’s a tough question. Recipes (here are two good posts: The Mad Fermentationist and The Paupered Chef) are in quite universal agreement that the goal is to reduce each duck breast’s weight by thirty percent. Unfortunately, the starting point for this measurement is before the salt cure and I neglected to way the meat until post-cure. Judging from how much moisture was pulled into the salt (a lot) I decided that a reasonable goal would be to have each duck breast lose fifteen percent of its post-salt weight through air-drying. Recipes also suggest that the duck be hung for between seven and ten days and that it should look drier and be stiffer and less yielding to pressure when it is ready. Here are the weight differences I measured after ten days of hanging:
- Duck Breast A went from 171 g to 147 g or a loss of 14%
- B went from 195 g to 170 g or a loss of 12.8%
- C went from 208 g to 181 g or a loss of 13%
- D went from 190 g to 155 g or a loss of 16.8%
I am a bit hard-pressed to explain the variation between B and D. They both started at roughly the same size and all of the subjective measures (colour, flexibility and pliability) are roughly the same. Speaking of the colour the transformation is quite remarkable as it goes from a bright livery red to a very dark purple-brown bordering on black.
When serving the duck prosciutto the first and foremost consideration is getting the stuff sliced as thinly as possible. Those with access to a meat slicer know how lucky they are and need not hear anything more from me on the matter and my related jealousy. For the rest of us, using a knife, we need to select our sharpest and longest knife. I hope it is self-evident why sharpest is best but length helps here because our goal should be to cut through the breast by dragging the knife in one direction: from heel to tip and towards us. As with pork bellly and smoked salmon it is easier to get really thin slices if you chill the duck breasts before cutting.
Duck fat has a stronger flavour than pork and a slightly chewier texture so if we can get it sliced “wafer thin” the fat should melt in the mouth before the eater begins to chew the lean. I feel pretentious explaining how to eat something but I really find this stuff is more delicious if you put it in your mouth, let the fat melt on your tongue and then start chewing the meat.
The flavour is great, especially for a first attempt. Obviously the salt comes through powerfully but it accents the contrasting and concentrated flavours of duck meat and duck fat. The Christmas spice version is subtle and definitely seasonally appropriate.