Extreme Specific Gravity

[ahwinney]

I'm planning on brewing a 20% beer very soon, but I just realized that my hydrometer and refractometer don't read high enough (1.2-1.25). Any suggestions on how to measure it and subsequently the beers progress?

 

[Psylocide]

Get a bigger hydrometer.

 

[ahwinney]

I just had at thought. I'll use a measuring cup, dilute the wort by 50%, multiply that gravity by 2.

 

[ajdelange]

Measure out 100 mL of wort. Add 100 mL of water. Measure the specific gravity and °P (or measure one and convert to the other with appropriate tables or formula). Determine the mass of the diluted wort as 200*SG*.998203. Determine the mass of extract as °P*mass_of_diluted_wort/100. Determine the mass of the water as (100 - °P)*mass_of_diluted_wort/100. Subtract the mass of 100 mL of water (100g) from the mass of water. Determine new Plato value from mass_of_extract*100/(mass_of_water - 100 + mass_of_extract). Convert to SG using formula or tables.