Kosher Laws

Why do we not mix fish and meat?

Shalom! 

Thank you for your question. 

It said that eating fish and meat together was the cause of a terrible skin condition and dangerous to one’s health. As such, the rabbis instituted a prohibition against eating them together. It is therefore forbidden to eat fish and poultry together, as well. Although nowadays there are no known health concerns about eating fish and meat together, the ban against doing still applies. 

As such, one should use a clean plate, fork, and knife (or other utensil) when switching from fish to meat, or meat to fish, due to the food residue that may remain on the utensil. Both foods, however, may be on the table at the same time. One person may even eat fish while another eats meat, and there is no need for any separation as is done when milk and meat are eaten at the same table. The prohibition against mixing fish and meat is unlike the one against mixing milk and meat. It is only forbidden to eat fish and meat together. A waiting period, however, is not necessary between the two. 

However, one should “wash” one’s mouth by merely taking a drink and eating something in between the fish and meat. 

 Pesachim 76b; OC 173:2, YD 116:2 and commentaries; Chatam Sofer 2:101.