Final specific gravity reading

Any hardware used for mashing, fermenting or aging.

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Hilltop
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Final specific gravity reading

Post by Hilltop »

After searching I couldn't find the answer I was looking for, so I made thisvthread. For years as some may know we " me and my better half" never owned a hydrometer. So this year, now that we have one has been interesting. I've never seen a mash go below 1.000 but I got one going now that is really heading south of that, I'm down to 0.995 and she's still going. What are the pros and cons here?

I ran out of alpha amalase but used the Gluco after the cook and went ahead and used sugar 48 pounds for a 5O gallon drum filled up. The mash bill is 50 lbs cracked corn, 15 pounds " my own wheat malt just for flavoring" and 15 pounds of ground oats. And the 48 lbs inverted sugar all steamed.

She's headed toward 0.990 as I have lots of activity left. I've never seen a mash go this good, this thing fried like bacon for 4 days, I'm using a mixture of mostly distillers yeast with a tad of bread yeast also, bout a cup.

My guess is I'm fixing to be stressing the yeast if I don't stop it, thoughts? Suggestions?
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Hilltop
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Re: Final specific gravity reading

Post by Hilltop »

I forgot to mention my starting gravity was 1.040 which seems kinda low so I'm confused! Lol!
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frunobulax
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Re: Final specific gravity reading

Post by frunobulax »

Did you calibrate or check your hydrometer for accuracy? Just put it in 60 degree water and see if it reads 0 Also remember that the readings are skewed if the temp. is above
or below 60 a correction chart shoulda came with it, if not just look online.
The wash can never truly go below 1.000 it just reads lower due to the presence of alcohol, and skews the reading a bit. The more alcohol the worse the reading can be off.
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Re: Final specific gravity reading

Post by Skipper1953 »

+1 to what frunobulax said.

It sounds like a temperature correction is needed. Fermentation will generate quite a bit of heat. You said it "fried like bacon", so that sounds like a pretty vigorous ferment.
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Re: Final specific gravity reading

Post by Pikey »

Water is 1.000 (ish depending on quality etc), Dissolved Sugar and other stuff push it up. When the sugar gets converted to alcohol, The alcohol has lower SG and the otaal SG of teh mix goes down. When the sugar is all used up, the Sg will be below 1.000. 1 lb sugar / gallon of water is low SG and low abv.

You don't appear to have done anything to extract anything except flavour from your grain bill - unless I've missed something so Yes 1.045 is low, but probably about right.
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Re: Final specific gravity reading

Post by bluefish_dist »

Temperature correction will only raise the sg reading unless you are below 60 deg. Higher temp means you are reading lower than actual for sg. Opposite of abv which reads higher if you are above the calibration temp.

As alcohol is less dense than water, the more alcohol and less sugar, the lower it will go. You may find that it drops quickly to .990, then slows down even though there is still bubbling. My vodka tends to drop to .99 in 2-3 days then takes another 1-2 days until the bubbling stops.
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Re: Final specific gravity reading

Post by Hilltop »

Thanks guys, I've hunted for the paperwork that came with the hydrometer but alas can't find it, and this particular hydrometer " cheap flea bay" type doesn't say what the calbration temp is on the hydrometer itself. My sample is 75 degrees.

Thing is, the mash has always quit once it hits the red at exactly 1.000, I always put it back in the tube it came in and have never abused it etc. That is the most vigorous fermentation I've seen. Once I take a clear sample filtered reading I often put the hydrometer in the barrel itself. My hydrometer was literally swimming around the barrel at 3 Knott's! Lol! I wish I could repeat the fermintation but I say that before tasting the hooch.maybe it bumped it's head. Think I'm just gonna order me a much better hydrometer and assume something has happened to mine.

I've experimented with various different grain bills and really like the taste of corn, wheat malt, and ground oats. The oats dial back the corney a tad and on oak this is one smooth drop. If the suger is inverted and then added to the steamed grain in this bill I don't notice any difference in taste.

It boils down to cost, I can make it with all grain and enzymes far cheaper than I can buy sugar. The cost of the sugar alone in this batch " keep in mind it was on sale for 5 bucks for 12 lbs" was 20 bucks. And those that taste it always point to the jar with the sugar added " up till now it was always 25 lbs of sugar.

4% alcohol content is why I went back to adding sugar and the fact that everyone says it's a little better. It's either that or grind the piss out of corn, cornmeal is just to expensive.

There is one other big difference in this batch, I steamed my oyster shells with the grain about 6 cups. I usually have to pH up and constantly check it, no more as adding the oyster shell in the cook itself solved that issue.

We left the outside world and moved in a camper with a smaller setup for the winter, my usual lactose infection didn't seem to follow, so I'm not sure what part the lack of the lacto will cause in taste difference. Maybe I bumped that hydrometer from the woods to the camper I have no clue but doubt it.

I'm using a type of what we call post oak now, it's native to Southern Dixie. It seems to impart a much better taste than straight white oak. It has long slender acorns and I find 5 days on it are all that's needed.

Thanks again
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Re: Final specific gravity reading

Post by Hilltop »

Pikey wrote:Water is 1.000 (ish depending on quality etc), Dissolved Sugar and other stuff push it up. When the sugar gets converted to alcohol, The alcohol has lower SG and the otaal SG of teh mix goes down. When the sugar is all used up, the Sg will be below 1.000. 1 lb sugar / gallon of water is low SG and low abv.

You don't appear to have done anything to extract anything except flavour from your grain bill - unless I've missed something so Yes 1.045 is low, but probably about right.
I basically ran out of alpha, I had two drops left I added it, but that's far too low an amount, I did add the Gluco. That's why I upped my sugar on this run. I try to limit ordering ingredients to make whisky online as I live in a very strict state with unbelievable laws. So I couldn't get to my brew supply shop to buy more high temp.

My wheat malt was homeade, it works but I believe I ruined some of it in the drying process. I have noticed in one blue barrel I don't even need yeast as it seems to live on the plastic forever. So maybe I got a little out of two drops and some weak wheat malt, not sure. The sugar covered any shortfall in conversion.

When I pick up the high temp I'm definitely getting a better hydrometer. Thanks Pikey.
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Re: Final specific gravity reading

Post by zapata »

Hilltop wrote: My guess is I'm fixing to be stressing the yeast if I don't stop it, thoughts? Suggestions?
I don't think you have anything to fear. There was not enough potential alcohol to stress your yeast, even if all the grain was converted.

Its possible it won't ever really stop though. The enzymes both added and in the malt will continuously convert the starches, slowly feeding the yeast. If you're really below 1 you can probably run whenever you want.

All hydrometers I've seen are calibrated at 60*. I know some are 68*F, but I always assumed they were really metric because 68*F is a nice round 20*C. You can verify with water, test it at 60*F and 68*F or really any temp and see if it corrects to 1.000. Or look closely at the print, maybe at the bottom, mine are labled on the scale itself. Correction calculator since you don't have your chart:
http://www.brewersfriend.com/hydrometer-temp/" onclick="window.open(this.href);return false;" rel="nofollow
Btw, your reading corrects to under 1.000 whether it is calibrated to 60 or 68 :)
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Re: Final specific gravity reading

Post by Pikey »

You're welcome mate 8)

You want to be aiming at a total sugar content (including any you get from the Grain bill) around about 1 3/4 lb per US gallon to get max abv - without over-stressing yeasts or wasting sugar. - Can't tell you what that is in SG as I just use table sugar and chuck it in to match 1kg /5 L total sugar, so it's not all dissolved at the beginning, but there are calculators about which will tell you that.

I expect it would be around 1.080 ?
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Re: Final specific gravity reading

Post by Hilltop »

These Hickory smoke blue barrels that I can get cheap are actually 5O gallons if I remember correctly so I fill em probably to the 44 gallon range to give me some headspace. I never add it up anymore. The only real issue I'm having with the indoor setup is outdoors it sure was nice to be able to boil a drum full of water at one time, now I'm only able to do 12 gallons at a time but I'm not in any hurry, when I get the steam wand in I just let it go for hours.

This setup is a step above that 5 gallon pot I first tried. Plus it's copper, and I never could get use to making whisky in stainless. Felt like I was committing a sin. I wish it would stop working as I'm ready to get Jiggy with it. I'm probably gonna start tomorrow regardless if it has a few bubbles going on.

It's slowed way down, but still trucking.
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Re: Final specific gravity reading

Post by Hilltop »

Wow, this batch after I stripped my low wines started out at much higher proof, 175 after my foreshots were tossed for a good while. I usually start out in the 160 range.
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Re: Final specific gravity reading

Post by Wino2Distill »

Perhaps your batch wasn't stirred properly when you took your initial reading. When I started mashing I would take a sample right from the top after the waiting period. The reading was always strangely low considering my grain bill. Eventually I figured out that I needed to stir. The SG went from 1.040 to 1.080.
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Re: Final specific gravity reading

Post by Hilltop »

Wino2Distill wrote:Perhaps your batch wasn't stirred properly when you took your initial reading. When I started mashing I would take a sample right from the top after the waiting period. The reading was always strangely low considering my grain bill. Eventually I figured out that I needed to stir. The SG went from 1.040 to 1.080.
Well that's exactly what I did, as it's so thick I have to actually filter some into a test tube to get a reading. I pulled it from the top. I'm gonna order a new one anyway as this is a cheapo. I also didn't calibrate it correctly.

Live and learn, but it turned out ok, I pulled 10 quarts off about 6 gallons of low wines so far that are excellent. I stopped when I hit the grain bed, I didn't strain the bottom I removed a third of the spent mash, added back more steamed grain and sugared it again.

I will run this next entire batch including squeezins and take a break. I'm liking this drop on oak, ultra smooth. Thanks guys
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