I am using a hand held Brix scale refractometer to estimate the amount of sugar in my rye mash.
My theoretical alcohol yield per ton should be higher so I am trying some sample stepped mashes and it is increasing the Brix reading quite a bit.
They are only samples so I can't easily ferment them out to see if the increase in Brix is actually fermentable sugars.
I do know that a refractometer "assumes" that there is only sugar and water present in the sample but there are a lot of other chemicals in the mix that will "obscure" the reading (same problem with obscuration with a hydrometer)
If any of you have a good understand the limitations of refractometers, I would like to be educated.
If you are not using beta-glucanase enzyme, the beta glucan is obscuring your refractometer. I have seen it add 20 point SG to a 1.060 mash. You think you have a 1.080 and you actually only get 60 point attenuation. It is a bit disappointing. Rye generally only has a 25 to 27 PPG contribution to a mash. It takes a third more rye for the same yield. as corn. So 1 ton theoretically should only yield 1200 lbs of sugar vs 1 ton of corn would yield nearly 1600 lbs sugar. This is calculated from sugar is 42 PPG corn 33 PPG and rye 25 PPG. Points are the last 2 digits on the specific gravity and PPG is Points per Gallon.
I am using 20% malted rye + 80 unmalted, adding beta-gucanase as well.
I know I could search for an online calculator, but could you tell me how many proof gallons 1200 lbs should yield?
Do you think the increase in Brix with stepping is fermentable or just an increase in an unfermenable?
Hi Pete: RE your thought on calculators, you can just do a simple PPG calculation with your grain weights as Sherman was alluding to and get ball-parkish. .