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Specific Gravity

Posted: Thu Jan 22, 2015 12:57 pm
by whistlewetter
Ok, from reading A LOT I stumbled upon a lot of posts where the topic of specific gravity was talked about. From what I have gathered and if I understand correctly you want your mash to start at 1.06 and when it drops below 1.0 that indicates that the fermentation process is done? Ok, so, if I am correct so far I have a question. I undestand that specific gravity is in relation to the sugars that are available to be converted to alcohol, hence dropping below 1.0 signifies the sugars have been converted to alcohol. My question is, again if I have a grasp on this, is it bad to be above 1.06? This is completely new to me and something I new nothing about until reading through this cool site. I've always went by a recipe and then waited for the bubbles in the air lock to slow to below 3 bubbles a minute. I normally do a corn and malted barley recipe and have the "peach brandy" recipe waiting to be distilled. Thanks in advance for the education.

Re: Specific Gravity

Posted: Thu Jan 22, 2015 1:01 pm
by bearriver
Forget watching the airlock. That is not good protocol, but perhaps a little fun at first.

SG will normally but not always drop under 1.0 when done. YMMV. Its done when the SG stops dropping.

Don't go over 1.07 for the best results. Lower is even better within reason. :egeek:

Re: Specific Gravity

Posted: Thu Jan 22, 2015 1:22 pm
by whistlewetter
yeah, after reading I figured the airlock watching wasnt the best practice. I am looking to learn the specifics on how to properly use this tool.

Re: Specific Gravity

Posted: Thu Jan 22, 2015 2:00 pm
by DAD300
An airlock isn't much of a tool for a distiller.

We ferment rather quickly, compared to wine and we don't really care if it gets infected, like beer. In fact a good infection can produce some amazing flavors.

Look for how lots of people ferment for distillation and you will find open to fermenters, loose lid food safe plastic trash cans and open top pots covered with a towel.

The 2015 whiskey of the year comes from a distillery that ferments in open top SS milk tanks.

Re: Specific Gravity

Posted: Thu Jan 22, 2015 2:28 pm
by Brutal
whistlewetter wrote: My question is, again if I have a grasp on this, is it bad to be above 1.06? n.
The answer, like so many things in this hobby, is maybe. It depends on what you like. The usual recommended starting gravity should be no higher than 1.060-1.070. This is what I always shoot for and I believe it makes the smoothest product. Some people go higher and if that's what you like then you can do it.

There are also some recipes where the starting SG is normally higher. Rum for example is typically higher. With rum there are lots of suspended solids that can make the reading artificially high, but some who make rum intentionally start high to stress the yeast and cause them to produce "esters."

Re: Specific Gravity

Posted: Thu Jan 22, 2015 3:04 pm
by MitchyBourbon
DAD300 wrote:An airlock isn't much of a tool for a distiller.

We ferment rather quickly, compared to wine and we don't really care if it gets infected, like beer. In fact a good infection can produce some amazing flavors.

Look for how lots of people ferment for distillation and you will find open to fermenters, loose lid food safe plastic trash cans and open top pots covered with a towel.

The 2015 whiskey of the year comes from a distillery that ferments in open top SS milk tanks.
Dad, I am a big fan of the many contributions you have made, especially the condenser controlled column and your position on smaller stills. I will have to disagree with this post.

An air lock is very useful tool for distillers. Are they required, technically no but they are the best tool to know if you have a vigorous ferment. If your ferment is lackluster you will know right away so you can do something about it. Without an air lock it may take you a day or more to find this out and if you don't have an air tight fermenter you will most likely end up with an infection.

An air tight fermenter with an air lock is the best way to prevent infection. Random infections are not welcome in anything I ferment. Unless I am experimenting, and when I experiment I do so with small volumes, then I isolate whatever bugs/strains that i have caught. Then i propagate each one and taste the beer from that individual strain. Only if it tastes good will i consider making a full batch. And if I make a full batch I make sure I ferment in an air tight fermenter with an air lock so I know exactly what I'm getting.

Re: Specific Gravity

Posted: Thu Jan 22, 2015 3:53 pm
by bearriver
MitchyBourbon wrote: if you don't have an air tight fermenter you will most likely end up with an infection.
I know AG is reported to be more prone to infection. This I have no experience with so my advice could be completely out the window when not dealing with sugar washes.

I ferment with a loose fitting lid and stir it with my bare hands, albeit after I wash em up first. Only rinse the equipment with plain water between ferments. Not once have I had an infection with over a thousand gallons fermented last year. Also haven't sterilized my room or equipment once. Most likely, it will be just fine from my experience.

Re: Specific Gravity

Posted: Thu Jan 22, 2015 4:06 pm
by whistlewetter
All good info for me so far. Thanks!

Re: Specific Gravity

Posted: Thu Jan 22, 2015 4:20 pm
by shadylane
JMHO
Ferments with a SG "starting gravity" over 1.06 take longer to finish and are more likely to run into problems.
They also make an inferior distillate.
The problem with counting bubbles is the fermenter must be properly sealed.
On a sugar wash I use an open fermenter with the hydrometer left floating in it.
With all grains the mash is usually too thick for the hydrometer to be of any use.
I watch for the cap to fall, the mash to begin clearing and taste to decide when it's done.
One of the problems with SG is it could mean specific gravity or starting gravity or even the final gravity of the ferment.

Re: Specific Gravity

Posted: Thu Jan 22, 2015 4:45 pm
by MitchyBourbon
I have only done a few sugar washes, I treated them the same way. I didn't get an infection either. I have read about many infections here. I have to believe some of them were sugar washes.

That said, there are differences between sugar washes and ag. Grains come with any number of wild yeast and other bacteria on them ready to go. sugar is much less likely to contain enough yeast or bacteria to compete with your yeast. Malts in Ag are not boiled. A good sugar head should call for the sugar to be boiled, this inverts the sugar and will kill off nearly any contaminants. Most of the sugar recipes also call for using 10 times the yeast beer or wine use. This is so the yeast will skip most the exponential growth phase to eliminate the production esters etc. This also minimizes infections.

Re: Specific Gravity

Posted: Thu Jan 22, 2015 4:55 pm
by CR33G3R
I personally always ferment with an airlock. I also always ferment in my basement so if I left an open ferment inside my wife would kill me. I find that like many other things in this hobby it is a personal preference. The airlock IMO gives you quick feedback as to how the ferment is progressing and also allows you to just leave it for awhile if you can't get to running it.

Re: Specific Gravity

Posted: Fri Jan 23, 2015 11:02 am
by whistlewetter
shadylane wrote:JMHO
Ferments with a SG "starting gravity" over 1.06 take longer to finish and are more likely to run into problems.
They also make an inferior distillate.
The problem with counting bubbles is the fermenter must be properly sealed.
On a sugar wash I use an open fermenter with the hydrometer left floating in it.
With all grains the mash is usually too thick for the hydrometer to be of any use.
I watch for the cap to fall, the mash to begin clearing and taste to decide when it's done.
One of the problems with SG is it could mean specific gravity or starting gravity or even the final gravity of the ferment.
What exactly do you mean by let it clear? My mash gets a lot lighter towards the end but far from clear. I do a corn, malted barley and sugar recipe. I am going to leave the sugar out of my next batch. I am trying to incorporate tools to help me duplicate my process such as learning to properly use gravity meter.

Re: Specific Gravity

Posted: Fri Jan 23, 2015 12:57 pm
by T-Pee
At the end of fermenting most of the solids will fall to the bottom and the wash will...well...clear.

tp

Re: Specific Gravity

Posted: Fri Jan 23, 2015 1:09 pm
by Brutal
To, uhh, "clarify..."

When "clearing" is talked about on the subject of mashing it does not indicate that the mash/wash will actually become "clear." It will become "more clear than it was" though, if you let it "clear."

Re: Specific Gravity

Posted: Fri Jan 23, 2015 1:48 pm
by whistlewetter
I like the "clarify" lol. As stated I used to go by the bubbles per minute to decide when to distill. One of my mashes is a lot lighter in color and you can see the settled stuff at the bottom and the cap is minimal on the top. Any suggestions on how to know I have gotten all the fermentation? I can't get the pic resized to attach.

Re: Specific Gravity

Posted: Fri Jan 23, 2015 1:58 pm
by Jimbo
whistlewetter wrote: Any suggestions on how to know I have gotten all the fermentation?
Take a SG and FG. Ideally with a refractometer, as the clearness of your clarified cloudy wort wont matter, but solids clearly cloud your reading with a hydrometer. If you go from 1.065 to 1.010 you did good, 1.005 is great. Occasionally the stars will align and youll hit 1.000

Barring that, rack it off when the ferment stops and the top layer is cleaning up and settling. (about a week, but could be 2 if its cool (cool=under 75F for bakers/distillers, under 65 for ale yeasts , under 60 for wine yeasts) Then wait a few more days. Racking usually fires up fermentation a bit more, then it will settle out with all the gunk falling to the bottom.

Re: Specific Gravity

Posted: Fri Jan 23, 2015 1:58 pm
by hamshine
taste it to see if it is dry "no sweet taste"

Re: Specific Gravity

Posted: Fri Jan 23, 2015 2:24 pm
by whistlewetter
It taste like wine with just a very faint sweetness.

Re: Specific Gravity

Posted: Fri Jan 23, 2015 2:29 pm
by whistlewetter
I do use bakers yeast and they ferment at room temp. The one I am referring to has been going since the 11th.

Re: Specific Gravity

Posted: Fri Jan 23, 2015 2:45 pm
by hamshine
whistlewetter wrote:It taste like wine with just a very faint sweetness.


Could always give a day or two and run it..

Hard to say from that description but it sounds pretty close. Did you get a FG on it yet?

Re: Specific Gravity

Posted: Fri Jan 23, 2015 3:10 pm
by whistlewetter
Right now the FG is 1.03.

Re: Specific Gravity

Posted: Fri Jan 23, 2015 3:12 pm
by Jimbo
whats the temp, youre only half done, if you trust the reading, it wasnt chunky in a hydrometer was it?

If youre sitting cool, you might could use a hot water bath to warm up and wake up the yeast. Bakers likes 80F, 75 min. Cooler than that and increasing risk for stalling out.

Re: Specific Gravity

Posted: Fri Jan 23, 2015 3:40 pm
by whistlewetter
Jimbo wrote:whats the temp, youre only half done, if you trust the reading, it wasnt chunky in a hydrometer was it?

If youre sitting cool, you might could use a hot water bath to warm up and wake up the yeast. Bakers likes 80F, 75 min. Cooler than that and increasing risk for stalling out.
I pulled the liquid sample just below what's left of the cap. I racked it to another container. I will put it some tub water and see what happens.

Re: Specific Gravity

Posted: Fri Jan 23, 2015 3:47 pm
by T-Pee
whistlewetter wrote:I racked it to another container. I will put it some tub water and see what happens.
Kinda late now. You left a lot of your yeast behind if it has settled.

tp

Re: Specific Gravity

Posted: Fri Jan 23, 2015 3:54 pm
by Jimbo
TP, these are top fermenting yeast, the ones that settled aren't doing much anyway. Besides there's plenty yeast even if it looks crystal clear. Beers that clarify for 6 weeks carbonate just fine in the bottle with a little more sugar is added for priming

Re: Specific Gravity

Posted: Fri Jan 23, 2015 4:01 pm
by T-Pee
Baker's yeast ferments on the top? (http://homedistiller.org/forum/viewtopi ... 3#p7283502)

The only time I've ever had a cap was using EC-1118 on apple juice. Rum, UJ, sweet feed...all had very little to no cap with baker's.

I'm confused (again).

tp

Re: Specific Gravity

Posted: Fri Jan 23, 2015 4:02 pm
by whistlewetter
I figured I might of screwed that one up. I stuck it in a tub of hot water as well as used a fish tank heater. I put another mash in the tub too just to see what happens. I currently have 6, 5 gallon mashes fermenting. I plan on building an insulated box big enough to hold two carboys and try to use a light bulb as a heat source.

Re: Specific Gravity

Posted: Fri Jan 23, 2015 4:06 pm
by whistlewetter
T-Pee wrote:Baker's yeast ferments on the top? (http://homedistiller.org/forum/viewtopi ... 3#p7283502)

The only time I've ever had a cap was using EC-1118 on apple juice. Rum, UJ, sweet feed...all had very little to no cap with baker's.

I'm confused (again).

tp
I get a nice cap on mine with bakers yeast. You can see a difference from the cap and everything under it when looking through the carboy. Big bubbles on top and a little thicker looking than what's below. At least in mine. I use two packs of bakers yeast.

Re: Specific Gravity

Posted: Fri Jan 23, 2015 4:07 pm
by Jimbo
yes sir. Distillers, bakers, ale yeast all create a foamy 'krausen' on top when they get rollin. In reality the east is throughout the whole mash or wash

Re: Specific Gravity

Posted: Fri Jan 23, 2015 4:08 pm
by T-Pee
Jimbo wrote:yes sir. Distillers, bakers, ale yeast all create a foamy 'krausen' on top when they get rollin. In reality the east is throughout the whole mash or wash
Yeah. I fergot about that since ww's ferment hasn't cleared yet.

tp