Rendered fat seeping out to water bath?

Hi, I’m using glad resealable zip lock bag. I’ve immersed my duck for almost 15 hours now at 160F. I saw that the water bath is oily now, which i assumed came from the duck fat. Is it normal to see rendered fat seeping out of the bag? I don’t think that the bag is leaking as it is brand new and the water is still clear (juice inside the bag is brown). Is the food still safe for consumption? Thanks!

Not at all normal, brad.

You don’t disclose how you sealed the bag, or if you tested the seal.

If you are using a light weight storage bag those seals are not meant to be used in a turbulent water bath,

  • nor in hot water,
  • nor do they resist internal pressures expanding the bag.
    Seasoned users who employ them often use bull-dog style clips to attach the bags to the rim of the vessel used keeping the sealed edge above water level.

I prefer to use purpose made bags and have never experienced a leak. The Glad brand did not fair as well as the other leading brand in Consumer Reports testing.

I suggest you consider using more critical thinking in your problem solving process.
What is the evidence the bag isn’t leaking? The colour difference?
And what about the significantly larger volume of cooking water as compared to the few ounces in the bag? Might that not account for some difference in color due to dilution?
Also duck fat molecules being lighter may escape from the bag while water doesn’t. It’s possible. Did you add any other fat to the cooking bag?

Your watery duck ought to be safe to eat, just unpleasant, unless you have introduced any harmful pathogens or chemicals during the cook.

Or did you have greasy hands when you were handling the bag so there was oil or fat on the outside of the bag?

How did you put the meat in the bag?

If you didn’t roll back the edge of the bag, some of the oil or fat might have scraped off and caught in the seal. It happened to me until I found on another site, the importance of rolling the edge of the bag back before putting meat in it.

Also, for long cooks over a couple of hours, vacuum bags or resealable silicon bags are best and save the zippered freezer bags for shorter cooks under 2 hours.