brix refractometer

[barry]

hi guys i got to go out so thought i would ask this now and catch up later. Ive got myself a brix refractometer from ebay (hong kong) but it needs calibrating. says to use dioptric oil but have none with it, also mentions distilled water but being a bit thick the instructions dont seem to clear. im sure there are plenty of you clever clogs out there that can explain how to do it for a simpleton such as myself.
cheers all
barry

 

[mexbigshow]

is this any help,

How to Calibrate and Use Your Refractometer
Before you start taking readings, it's very important to calibrate the refractometer. Some refractometers require the use of a special calibration liquid to perform this task, while others are calibrated with distilled water.
Begin the calibration of your refractometer by lifting up the daylight plate and placing 2-3 drops of distilled water on top of the prism assembly. Close the daylight plate so the water spreads across the entire surface of the prism without any air bubbles or dry spots.

Allow the test sample to sit on the prism for approximately 30 seconds before you attempt calibration in the next step. This allows the sample to adjust to the ambient temperature of the refractometer.
Hold the refractometer in the direction of a natural light source and look into the eyepiece. You will see a circular field with graduations down the center. You may have to focus the eyepiece to clearly see the graduations.
Turn the calibration screw until the boundary between the upper blue field and the lower white field meet exactly at ZERO on the scale.
Once the refractometer has been properly calibrated, you are ready to take readings of grape juice or whatever else you want to sample. Put away the calibration screwdriver. Clean the instrument (both the daylight plate and the top of the main prism assembly) using a soft, damp cloth, then place 2-3 drops of the desired sample on top of the prism. Close the daylight plate and take your reading as before.

 

[Erichalfbee]

You can't use water as the scale doesn't go as low as zero
Below is what I found on my Google travels so I calibrated mine to 71.5 Brix


Refractometers can be calibrated using a known calibration liquid. Calibration oils with refractive index equivalent to around 70°Bx are expensive and difficult to obtain.
Virgin olive oil is specified by the UN FAO in CODEX STANDARD FOR OLIVE OILS AND OLIVE POMACE OILS CODEX STAN 33-1981 (Rev. 2-2003) to have a refractive index from 1.4677 to 1.4705 at 20°C which corresponds to 71°Bx to 72°Bx.

 

[Midland Beek]

I assume that mine came calibrated.

 

[Erichalfbee]

Probably did. When I calibrated mine with Extra Virgin Olive Oil the reading was 72

 

[Winker]

I assume that mine came calibrated.

Me too, so i just tested mine with some extra virgin olive oil the reading was 71

 

[barry]

Thanks for the advice, have just used extra virgin olive oil and it came out at 71. Have just tested two very small buckets of honey , one came out at 20%, the other at just under 21%. Do you think the 20% will be ok to jar up and the 21% ok to use for making mead,

 

[drstitson]

if you're talking two small buckets - even the 21% will be fine for personal use over a relatively short timespan. just keep it airtight as much as possible.

 

[barry]

thats good news, we'll start tucking in now then

 

[oliver90owner]

Low temperatures inhibit yeast growth. Keeping it in a freezer would reduce the yeast activity to approximately zero. Even a fridge near zero would virtually stop any fermentation.