If I put a Kosher condiment on a non-Kosher sandwitch does that mean I am going to eat a Kosher sandwitch.
No.
ETA: If you put a slice of tomato on an hamburger, does that make it vegetarian?
Absolutely not. All ingredients must be kosher.
Thank you all in one
OK, now tell us about the effect non-kosher condiments have on kosher sandwiches.
The rule is
kosher + nonkosher = nonkosher
If any single element in a dish is non-kosher, then the whole thing is rendered non-kosher. The analogy to vegetarianism is apt.
I’m not Jewish, but I think this is correct. If you are a devout Jew and are concerned over whether or not something you prepared or want to prepare is Kosher, I’d think that a call to your rabbi would be best.
Yeah. A drop makes the whole thing treif.
I’m sort of curious how anyone could think it could be otherwise. I mean, if it were that simple, then observant Jews wouldn’t, in effect, have any dietary restrictions at all: Just sprinkle a few grains of salt on everything, and it’s fine.
My brother the plumber once called a rabbi friend of his for advice on the drains in a kosher kitchen. This kitchen had separate milk and meat dishwashers, and he needed to re-plumb the drain lines to make them drain correctly. The customer was very happy that he went the extra mile to ensure that the kitchen would remain kosher.
Thanks. The three Jews that posted prior to you have confirmed your speculation.
make the 3 Jews 3 opinions joke, or was it 2 Jews 3 opinions?
I think it’s the latter. 
Oh it was “Two Jews, three opinions”. But in this case, they were unanimous.
I have to admit that I have never heard of meat and milk dishwashers. There is a conceptual problem. You might think that a “parve” dish might be go in either. But the logic of having separate dishwashers is that a dish becomes contaminated by anything it shares dishwasher with. Therefore you would need a third for dishes (such as serving dishes for vegetables) that you might use with either a meat or dairy meal.
No problem. You’ve got one set of dishes for meat (and non-meat products in meat-based meals), and one set for dairy (and dairy-based meals). One set is washed in each dishwasher, and never the twain shall meet.
Never the drain shall meat? Hmm. There’s a pun in there somewhere…
For most circumstances, this isn’t quite accurate:
http://www.chabad.org/library/howto/wizard_cdo/aid/113636/jewish/The-160th-Rule.htm
It has to be more than one-sixtieth by volume.
Why don’t we ask 2 Jews and find out?
What’s the rule for making a cooking pot “reKosherized”? That is, if I use a Kosher pot to cook some ham, can I make it clean again? Something about burying it in the yard for “x” amount of time comes to mind, but I could be wrong.
John Mace:
No burying. The rule is “The way it (the flavor) goes in, that’s how it comes out.” Leave the pot unused for 24 hours, scrub the surface clean. Then, if the pot was used to cook it with liquid, fill it with boiling water and cause the water to overflow the rim (e.g., throw a rock in). If it was used over dry fire, run over the entire thing with a hot flame (e.g., a blowtorch).
That’s for metal pots. Earthenware can’t be re-made Kosher, it must be discarded if rendered non-kosher.