Dear Rabbi Simon
We are renewing our kitchen (a costly but rewarding endeavour). I am looking at an Indesit built-in electric double oven (£269 from John Lewis). May I simply designate one oven for meat and one for dairy, or do I need two separate single ovens?
While the luxury of two separate single ovens is preferred by some fortunate homemakers with plenty of room in their kitchens, the double oven you are considering is fine from a kosher kitchen standpoint. Some say best to designate top oven for meat, as steam rises, however this is not essential. In general, I suspect you will find it is not that frequently that you will want to use the two ovens simultaneously for meat and milk respectively.
The following edited excerpt is taken from a reliable Kosher website:
CAN I USE A DOUBLE OVEN – THE TOP ONE FOR MEATY AND THE BOTTOM ONE FOR MILKY?
To allow the two compartments of a double oven to be used for meaty and milky, one would need to establish that the two compartments are indeed totally separate ovens.
In some cases, the compartments share a single sheet of metal which acts as a barrier between the two. From a kashrus point of view, this is problematic as food flavour from one session can be imparted into the cooking during the other session.
Ideally, you will want to research your oven before purchase. A look behind the appliance will show whether the inner casing of the oven is a shared wall or two separate pieces of casing. Alternatively, call customer services to ask the company you are buying from.
Although there is further potential concern where the two ovens vent into each other, in modern ovens this is rare.
Hope this helps.
Rabbi Rashi Simon