Refractometers, How Do They Work? (And Should You Buy One?) 

More to come!

Glad you enjoyed it!

Looks like Lance answered this in his video ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-yF2fIaQS70k.html

Yes you can! The rule of thumb is multiply by Brix by 0.85 to get TDS.

You should use the same water you use to make your coffee, as long as you use filtered water (i.e. bottle water, not natural water)

You can message renegadeguru in the espresso aficionados discord

@@jkimmakes This metal piece that you use instead of the plastic door on the refractometer. Can you explain the benefits? Does it have a name. I have tried to contact renegadeguru.

@@NebbieLoon I'm the one who makes these 👋 (I'll answer your Discord message too) It's nicknamed the "magic mushroom", mostly because of the shape. The 'shroom's purpose is to rapidly cool a sample and prevent evaporation, because temperature has a large impact on refractive index and therefore on TDS reading. While not necessarily quite as accurate as cooling each sample in a carefully cleaned separate closed container, it's much faster/more convenient, and far more accurate and consistent than dropping a hot sample into the refractometer.

Hey coffee machinest thanks for the response! Are familiar with this specific refractometer that jkim is using? Is it accurate enough for general coffee nerd purposes?

@@Andrew-wp1bz Just saw this - yes, the yellow refractometer (sold under a number of different chinese-based brands, on Amazon/ebay/Ali, colloquially the "yellowboi") is one of the cheapest available refractometers with enough accuracy and precision to use with filter coffee. Make sure you get one intended for coffee, as coffee has a different TDS:refractive index curve than sugar (brix)/alcohol/saline. It's a little more finicky than an Atago or VST, but with careful use it can produce good results

Link to AliExpress page in the description