Best Stainless Nozzle  

In practice almost all clear or natural coloured filaments are food safe, PETG is almost identical to the bottles many of your drinks arrive in ... but there *might* sometimes be issues with the pigment used in coloured filament 'though detectable leaching is rare.

Filament is melted at temperatures far higher than pathogenic bacteria can survive so the polymer is effectively sterile as it leaves the nozzle.

I don't know of any stainless steel nozzles but neither can  think of any need to use them, they will not be as good at transferring heat: the amount of brass worn from a conventional nozzle in each print is tiny (unless you use abrasive filament) you can expect to lose about 5 grams in a year's printing - divide that by the number of prints and then compare it with the amount transferred to an omelette from  a copper pan... 

The standard advice is to avoid printing food containers and crockery because the fine interstices especially between the layers can trap food fragments and harbour bacteria - this is true, however hot soapy water can get everywhere a bacterium can - so it really boils down to how diligently the parts are washed.  Most people apply a food safe resin coating to anything that might become a risk.

Your problem will not be in making food safe ware for your own use, but, if you wish to sell it, in getting certification (lot's of expensive testing) and insurance.

Cheerio,

RE: Best Stainless Nozzle

Unless you use PP (polypropylene) you should coat the print with a sealant like XTC-3D or Siraya Tech Aegis. Otherwise, the part will not be water tight and will start to get moldy.