Monday, August 29, 2011

Not ducking the question.


Celia of Fig Jam & Lime Cordial, asks

"I've been making confit duck, and keep it for a short time in the fridge.

1. As instructed, I've been reheating the used duck fat to clarify it and then storing it in the freezer to be reused next time - is this a safe practice, and how many times can the fat be reheated and reused like this, please?

2. Secondly, confit duck (a traditional food) has been stored for generations by the French on the pantry shelf, with some instructions going so far as to say "don't worry if the bones not covered in fat go a bit green". I don't do that, I keep it in the fridge, but wondered whether it was actually safe to store meat like this unrefrigerated?

Question 1. It is a matter of taste. Over time there is a likelihood that the fat will start breaking down but that in itself is not harmful. The issue is whether the taste is affected. My Granny had a 'dripping pan' that used to hold fat that was returned time and time again to the weekend roast, with no ill-effect. Animal fats are generally too saturated to have oxidative rancidity and hydrolytic rancidity (the splitting of the fatty acids from the glycerol backbone of the fat) often cannot be tasted. A text book I read once famously said that a fat was rancid if it tasted rancid and that all other tests were, at best, just corroborating evidence.

The splitting of the triglyceride happens during digestion so it is no a health hazard as such.

So, in short: as long as the fat still tastes ok, it is fine.

Question 2. The fat layer is supposed to keep the meat protected. Despite what advertisers of disinfectants and such like would have you believe, bacteria do not spontaneously appear for no good reason. This is a habit solely retained for the start of a new Universe. If your duck is cooked, it will be sterile and the thick layer of fat will keep it sterile.

Has done so safely for many many years.

Green is more problematic but not necessarily harmful. The pigments in blood - haemoglobin and myoglobin, will oxidise and go funny colours, mostly green, grey and brown, with exposure to the air. Unsightly but not harmful. The surface of the chicken paté I make discolours quite quickly but is not harmful.

More important is to make sure that the exposed bones and such like are not handled as they do not have the layer of protective fat and will possibly give bacteria a toe-hold.


  1. Thanks so much, Lee, that's all really good to know!

  2. Thanks for posting this. I make chicken paté and
    have often been concerned about the color change.

  3. Hi I see this is a old post but i need a question answering. I cured 6 duck legs in a salt and herb mixture for about 1 days. I then confit the legs till very tender and then transfered them to sterilised kilner jars. I placed two confit duck legs in each jar so they wasnt all stuffed in together, I then poured the hot duck fat over them and filled the jars to the top and totally submerged the duck legs with no visible bone or flesh exposed. I have had then in a fridge for about 12-14 months now and was wondering if these are still ok to consume. visually and appearance they look ok with no discolouration but i was just wondering if looks can be deceiving. I confit these ducks for a very special dinner party i planned and i dont want to kill my guests knowing their duck is over a year old

    Kind Regards

    Stefan Leyland

    1. Hi Stephan, the duck and fat will have been sterile due to the cooking/heating. The jars are sterile. The fat layer acts as an air barrier. They have been kept refrigerated. In short, they will have started thier life bacteria free and there will have been no way that bacteria could enter the product and they have been kept outside of the danger window (>5degC). All the boxes are ticked. There is no reason to think they will be unsafe to eat. Wish I could have a taste, actually.


Moderation cuts in six days after posting.