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For those of you who have rotary evaporators or other chemistry glassware in the kitchen, what do you use to grease the ground glass taper/ ball joints so that the lubricant does not either absorb or introduce flavors into the product?

Thus far I have not found anything that is a GRAS food additive marketed as a vacuum grease, but I have found some very expensive fluorinated/ PTFE compounds (Santovac 5GB) that would be insoluble in any food items being run through the system.

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up vote 4 down vote accepted

Many manufacturers and manuals say that you shouldn't grease them. However, for parts of the process you may be able to use Taylor ice cream machine lubrication or Vaseline (see below).

Dave Arnold who also runs the Cooking Issues blog, is the king of RotoVap in the kitchen. There is a full article over here on Dispensery Grade where he discusses RotoVap in the kitchen.

Here's an excerpt from the comment section of the article:

What are you using to grease the glass joints (air inlet and vacuum take-off)? Regular vacuum grease is probably not a good idea. Something like chapstick or shortening? Thanks.

Reply Dave A // Dec 12, 2009 at 11:22 am

Howdy Stephen, We use Taylor ice cream machine lubrication or Vaseline.

If you go with vaseline, make sure you get the food-grade version.

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rather than padding with dots, could you explain (even if you feel it's self evident) why it won't affect the food (just because we put something on our lips doesn't mean we're willing to eat it, eg lipstick or flavoured lip gloss) and why it will serve the purpose of lubricating the equipment or seal? – Kate Gregory Aug 16 '13 at 23:52

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