From the Rav’s Desk: The dairy or meaty status of a sous vide cooker and its container

1. Question: [Tuesday, 15^th Iyar, 5781]

I would like to know if it is permitted for one to use a sous vide cooker stick and container for both meat and dairy. Just to explain a little bit of how sous vide cookers work: One fills up a container with water and the food that is being cooked is placed in an airtight bag which is then placed inside the water which is heated with the cooker stick. The airtight bag is supposed to prevent their being any direct interaction between the food in the bag and the cooking stick, or the container and water that is in it. My question is, since there is no actual contact between the water container or stick with the meat inside the bag then perhaps it should be viewed as Pareve, and I would be allowed to use it also the cooking dairy, and foods that I would like to eat with dairy.

Answer:

A sous vide cooking stick and all of its accessories [i.e. water and container] receive the same status as the food that they are cooking even though the food is inside an airtight bag, and therefore if one used it to cook meat, it and all of its accessories are considered meaty just like a regular pot of meat, and therefore it is forbidden to use it to cook dairy products. [Regarding using it to cook Pareve foods that will then be eaten with dairy this follows the same law as using a meat pot to cook Pareve foods which will then be eaten with dairy in which case there is a difference between Sephardim and Ashkenazim and between whether the cooker is Ben Yomo or not.]

A glass container: Even if one were to use an airtight glass container [i.e. canning jar] to cook the meat, all the above laws would still apply for both Sephardim and Ashkenazim, and all the accessories would be considered meaty.

Explanation: Although to the naked eye it may seem that there is no interaction between the food in the bag and the cooking accessories when using a sous vide cooker, this is not how Halacha views things. According to Halacha whenever there is heat and moisture involved between two items it has ability to fully transfer taste throughout all the substances that contact each other, even indirectly. Thus, being that meat products in the bag contain moisture and fat, and the bag is surrounded by water, and the water reaches a temperature of Yad Soledes through a product that is inside of it, it therefore it has the full status of a Keli Rishon and the meat has the capability to transfer taste through the plastic bag and into the water and into the sous vide cooking vessel and its container. In such a case we would not even view the transfer of taste into the cooker as indirect Nat Bar Nat taste but rather as direct taste and therefore if it was used for dairy foods within 24 hours one would require 60 times versus the meat/vessel. [In truth, even if we view it as indirect taste of Nat Bar Nat we would still require it to be designated as meaty, even though we would require 60 times.] All the above is aside for the fact that it’s not uncommon for the so-called airtight bag to not be airtight, and allow for water to enter, hence making it directly similar to a case that one use the sous vide cooker to cook meat directly without a bag. Bottom line, it is clear due to all the above that a sous vide cooker must be treated like the status of a regular pot, of which we rule that if it is used to cook meat then the pot becomes the meaty. Now, regarding the use of an airtight glass canning jar, this would still be a problem due to the following reasons 1) Ashkenazim generally rule that taste gets transferred even through glass 2) even according to Sephardim, it is a problem being that at the very least the lid of the glass jar is made of metal through which taste can transfer.

Sources:  See regarding the ability for taste to penetrate through a pot: See Michaber and Rama Y.D. 92:5-7 regarding milk that fell on the side of a meat pot and a pot that was placed on top of spilled milk; Shach Y.D. 105:23 regarding if food fell on top of a Treif vessel and the difference regarding if the food was fatty or lean or dry or moist; See P”M 92 M.Z. 29 and P”M O.C. 173 A”A 1 that when food falls on top of a pot that contains liquid it possibly transfers 60x since there is liquid inside; Chavas Daas 95 that we don’t apply Nat Bar Nat regarding cooking; Maharsham 5:76 regarding if a piece of completely dried meat touched a dry hot pot of milk from the outside that even then the milk inside is forbidden and the only question is regarding the meat if it absorbs more than a clip is worth. Bottom line, even according to his more lenient response it is clear that he would agree in our case that the sous vide vessels become fully meaty!