eGullet scientists, I'm having a little trouble at work with some foie gras we are using oxidizing rather quickly. The end result is a 1x1x3cm piece of terrine, although the word may not be exactly suitable for what we're doing. The process is this (metric): Separate the foie gras into lobes. Brine 24-48 hours in a milk/nitrite solution. I've tried a range of percentages, from 0.5% (5g /kg) - 1.0%, with not much discernible difference. Remove from brine, pat dry, season with salt, sugar, pepper, vacuum pack, cook in 65 C water bath until 55 C at heart. Shock, and then pass through a tamis to remove veins. It's then put into an even layer on a GN tray, cooled to set, and cut to specs. It yields a smooth, consistent, nearly waste-free product - with the exception of the rate of oxidation. I have done the same process and yielded a product that remained a natural pink for up to 72 hours. I have done the process and lost the foie gras within 12 hours. I've done it and skipped the brine/nitrite altogether, which has yielded such a result that I question whether the brine/nitrite is even worth it. I've made a salt mix (94% salt, 6% nitrite) and then used this mix at 12g/kg dry. It created uneven oxidized patches on the liver. Chef de cuisine contends that putting it through the tamis, and thus exposing so much surface area, is the culprit. It makes sense, but i have reservations, as i have done this perhaps 75+ times, and gotten a beautiful result. There seems to be no consistency to the problem. I have also been making a separate terrine, in a different process - tempering the foie gras, removing the primary and secondary vein, using a minimal amount of clean straight cuts, in order not to damage the foie gras, and then brining this. Seasoning the following day, mold in cylinder, wrap in film, cryovac, cook sous vide to 55, shock. This also seems to oxidize more quickly than it should. Chef de cuisine, who recommended the brining, as practiced by french charcutiers, also mentions they are using saltpeter (potassium nitra/ite?), and possibly sugar, but it can tend to cause that bright pink unnatural look. I have ordered and received this, but another variable in this equation is that I am in mainland China, and am cautious about adding these chemicals to food, as i cannot guarantee that they are explicitly food safe - it goes without saying that we do not want to cause any harm to our customers. Other possible variables - foie gras itself is locally produced (Shanghai). Purity of nitrite (?). Thanks for any other suggestions.