More Alcohol Produced Than Calculated

[RiverBooze]

I'm almost done stripping a CROW whiskey AG mash and the volume of alcohol produced is way off (to the good). When I pitched the yeast the SG was 1.066. It finished at 1.000. By the numbers, the mash should be about 8.5% alcohol. So far I have stripped 29.5 gal (2 runs) and produced 9 gal of alcohol at 35%. Using the Distillate To Water Calculator, it shows the mash was about 11.25% ABV.
I still have 19 gal of squeezed out liquid mash left to run. Curious if it will produce the same as the "top of the barrel / cleared" first runs (I'm assuming it will). If so, then I'm curious how the extra ABV was created during fermentation.

I'm sure the experts will ask for more info on the mash so here goes...
Grain Bill:
60# white corn meal (Pearl Milling Co)
50# white wheat malt
9# rye malt
6# flaked rye
10# rolled oats
60 gal water added to grains
Total mash volume was about 72-74 gal

I basically used the easy large batch mash method.
Boiled water and added to corn meal in a cooler, stir in liquid HTA, let set 12hrs stirring a few times. Then added powder gluco (temp about 145), let set another 10ish hrs.
After HTA was added to corn and it was working its magic, I started on the rye. Heated water to 185ish, killed the heat, added flaked rye, then about 10ml of HTA because.. why not? After 1.5 hrs, added a little water to cool to 150 and added rye malt. Stir and cover. After couple hours the temp was around 130ish, I added a dash of powder gluco. Re-cover and let set overnight.
Next day, heated water to 155 and added to wheat malt in cooler, stir and set for about 2 hrs. Added a dash of powder gluco (temp 135), stir and set for a couple more hours.
Started on the oats, basically same process as corn meal.
Combined corn, rye and wheat into one fermenter and added more powder gluco, (because why not?). Following day added the oats and last of water to get everything under 90 deg. Starting SG (corrected for temp) was 1.066
Pitched a combo of red star DADY, EC-1118, & Jack's Mead yeast.

Any thoughts??

[NormandieStill]

Firstly, what are you using to measure the FG? Refractometer readings need correction for alcohol.
Secondly, in an on-grain ferment the enzymes can continue to do their thing while the ferment runs, exposing more sugars for the yeast as time goes by. Essentially your SG is increasing but your yeast are also eating sugars at the same time.

[Deplorable]

I'd check the alcometer against a cylinder of distilled water, and correct for temperature. That sounds suspect. My 23 gallon ferments, averaged, start in the ballpark of 1.067 and always finish under 1.000. The stripping runs yield between 5 and 5.5 gallons at 30%.

[OtisT]

Both of the above posts are plausible. I’ve experienced something similar to what NormandieStill described, especially with rye. I chalked it up to an incomplete conversion during my mash process.

[RiverBooze]

SG & FG was measured with same hydrometer. Alcometer reading is correct (0 in distilled water), but I'm reading it as hobbyist not a scientist... (Those lines on the bottom are really close and really small. And I don't have a magnifying glass.) So, I'll say my reading is accurate within 1.5%. Even at 33.5% low wines, that's still 10.75% ABV mash.
NormandieStill, this is exactly what I was thinking. Maybe the extra gluco I pitched payed off.

[bilgriss]

The Gravity Readings would indicate 8.65%. 29.5 * .0865 = 2.6 Gallons.
9 * .35 = 3.15 of alcohol. This would seem to mean you created an extra half gallon of pure alcohol during distillation. More, since you don't get 100% yield.

Obviously, that's not what happened.
Either a measurement was wrong, a measuring device is inaccurate, or the medium measured has a variable not being considered. I don't feel like I have enough information to tell you which one is the correct answer.

[jonnys_spirit]

Finish your strip and spirit runs. I think you’ll get about 3-3.5g 60% after cuts.

You have about 135# of grain listed. You can use less or more water but the grain remains the same. Grain=likker. Water does not=likker.

I convert about 100# into 2.5-3g after cuts. Maybe a little more than 100#.

The enzymes will continue to convert starch into sugar through fermentation to a certain point. That may be why SG is not 100% accurate. Might be a temp error or something like hydrometer calibration weighing into it too?

Cheers!
-jonny

[RiverBooze]

Mystery Solved!!
Thought about it more after Bilgriss post. I calculated the total gravity points of the grain (4847) and divided by the 60 gal of water added. This came out to a potential 10.42% ABV... IF there was 100% conversion (which is impossible as far as I know).
So I started looking at my instruments again and let me find that magnifying glass too.
Remember when I said my Alcometer is correct, reading 0 in water, well... I checked it about a year ago... And I honestly can't remember if the one I've been using is the same one I tested or a spare one. Both were el-cheapo Amazon buys. SMH.
I had recently picked up a new one from the local BS (LD Carlson brand) for a friend. So I did a quick side by side comparison and sure nuff... the el-cheapo reading was different.
Then I had to go buy some distilled water see which one was correct (although I pretty much knew the cheap one was wrong). Tested the LD alcometer (calibrated at 60 deg) in distilled water at 61.4 deg and it was dead-on 0. Checked the el-cheapo in the same water... reading was 10%. I don't know if it is calibrated at 60 or 68 deg, but either way, it's wrong!!

So... Lesson Learned. Check instrument calibration periodically, not just one and done.
And for those wondering... So far I have stripped 44.5 gal of mash, yielding 13.75 gal of low wines at 26%. And I still have 4 gal of mash left to add to the LW for the spirit run.

[subbrew]

Nice to see you are making enough to let some age. That is what I have been trying as well. Do 40 gallon mashes so I get enough to fill a badmo clone with 1.75 gallons and put a bit less than a gal on glass. Let's me have the product on glass in a year or two and save the badmo for at least three years.

You have my curious to check the calibration on my el cheapo hydrometer and refractometer as well.

[bilgriss]

Glad you got it squared away, although it's a little disappointing that we can't magically increase yield during distillation!

[RiverBooze]

Totally broke my heart Bilgriss! For a min, I thought the angels were giving some back! LOL

Subbrew, this is my second run on this recipe. The first has been in a 10L (2.64gal) barrel for about 4 months. Plan to move first run to a 5gal barrel and top off with this run. Then refill the 10L with whatever is left. And hopefully keep my greedy hands off it for a year or 2.