Why do we use SG and not Brix?

[NorCal]

I deal with a dozen commercial winemakers on a pretty regular bases. Not one has ever referred to the specific gravity of the grapes or must, it is always Brix. I’m curious why most on this “winemakingtalk” refer to SG Vs. Brix?

 

[DoctorCAD]

Bris gets altered by alcohol and SG does not.

 

[mikewatkins727]

I use them both. Brix when I am setting the starting S.P. because I have formula for correcting (or adding sugar).

I use S.P. for calculating alcohol.

Note: I ferment fruit wines mostly. (But not much longer, Been diagnosed with Rheumatoid arthritis and the medication will stop the consumption of alcohol).

 

[Johny99]

Me, I use brix.

 

[sour_grapes]

That is a good question.

I like SG, because that is what we actually measure. You measure SG. You infer Brix. So, personally, I am happy that the hobby winemaking world seems to use SG.

Honest question: What do commercial winemakers refer to during the course of fermentation, as the sugars drop? Do they talk about how many Brix the must has left, and, if so, how do they measure this? I am guessing they mean "the Brix that a must of this SG would have if it contained no alcohol."

 

[Johny99]

That is a good question.

I like SG, because that is what we actually measure. You measure SG. You infer Brix
Honest question: What do commercial winemakers refer to during the course of fermentation, as the sugars drop? Do they talk about how many Brix the must has left, and, if so, how do they measure this? I am guessing they mean "the Brix that a must of this SG would have if it contained no alcohol."

The two I’ve worked at in my early learning, used Brix. The initial reading was important. Subsequent readings were used at both to plot the progress of fermentation. I don’t believe the absolute number was as important as the trajectory of the curve, so the alcohol influence wasn’t talked about. Curves were compared to other “good” ferments. Both used hydrometers to measure. I’m not sure how the digital meters work or if the brix reading is compensated for alcohol and non-sugar solids.

 

[stickman]

I've always used brix until the fermentation gets below 0, maybe because it seemed easier to understand in the beginning, 24brix tells me something, 1.10 requires a little more work. I suppose it is a matter of what numbers you get used to seeing.

 

[Johnd]

For me, it’s a matter of instrumentation and familiarity. The instrument used at the must stage is the refractometer, mine reads BRIX, and that’s what I use at that stage.

As fermentation progresses, the hydrometer becomes the instrument of choice, and one of familiarity, since I started winemaking with kits, and the SG readings were the readings I learned with. Personally, I’m quite comfortable with both.

 

[balatonwine]

Good question.

May be just regional and historical in industry versus hobbyists. As in, why do some use metric, and other use Imperial? FWIIW, in Germany/Switzerland, they don't use brix or specific gravity that much, they use the Oechsle scale. Thus, my Swiss refractometer uses Oechsle, while my Hungarian hydrometer uses brix.

 

[Boatboy24]

How do the commercial guys determine ABV? Do they use Brix? Or do they have tools to measure? I haven't searched extensively, but every ABV calculator I've seen uses SG, not brix. Not having fancy lab equipment to test ABV, we have to compute it and we use SG.

With grapes, I use Brix because that's what my refractometer measures. From there though, I convert it to SG to track fermentation and calculate ABV.

 

[NorCal]

How do the commercial guys determine ABV? Do they use Brix? Or do they have tools to measure? I haven't searched extensively, but every ABV calculator I've seen uses SG, not brix. Not having fancy lab equipment to test ABV, we have to compute it and we use SG.

With grapes, I use Brix because that's what my refractometer measures. From there though, I convert it to SG to track fermentation and calculate ABV.

I use this calculator to determine SG or final ABV. All my precision hydrometers, which require a liter of liquid to measure, only read brix. The other one that is most commonly used has SG, Brix scales on them.

I can relate to a brix reading of 12.9, meaning that the solution contains 12.9% sugar, a lot more than having a SG reading of 1.0920. I’m not saying it’s better or worse, just that outside of this forum I don’t see or speak of an SG reading, in any other term than brix.

 

[sour_grapes]

I can relate to a brix reading of 12.9, meaning that the solution contains 12.9% sugar

I understand what I am about to niggle on is not important in practice. However, if you get a "Brix reading" of, say, 12.9 during fermentation using a hydrometer, it does NOT mean that the solution contains 12.9% sugar. The alcohol alters the density, too, so that reading does not directly reveal the true amount of sugar left. (Obviously, it is close enough for our purposes.)

This what I meant upthread by I am guessing they mean "the Brix that a must of this SG would have if it contained no alcohol."

 

[NorCal]

As it is going through fermentation there would be some inaccuracies knowing precisely how much sugar is left (without proper compensation) as there would if you were tracking SG.

My point is that, with the exception of this forum, all the discussions with all the winemakers in my circle of contacts talk in terms of brix and not an SG number.

Not saying it’s wrong, I’m just curious why. A carry over from beer making?

 

[pgentile]

Not saying it’s wrong, I’m just curious why. A carry over from beer making?

Also kit instructions, I have only done WE and Fontana kits, use gravity.

 

[JohnT]

Brix and SG are two different scales that are on the same hydrometer.

I got into using brix and never converted myself over to SG.

To me, measuring Brix gives me an immediate look at where we are and how much further we have to go in a way that is simple to understand. To a fellow with a simple mind, if I start with at 25 brix, and have 12.5 brix to go, it is easy to understand that we are half way there. Perhaps simply because I am not used to the SG scale, but a SG reading of 1.100 does not make sense to me.

I know that a reading might not be accurate, but is pretty darn close. After all, this is wine and not rocket fuel.

 

[Redbird1]

As it is going through fermentation there would be some inaccuracies knowing precisely how much sugar is left (without proper compensation) as there would if you were tracking SG.

My point is that, with the exception of this forum, all the discussions with all the winemakers in my circle of contacts talk in terms of brix and not an SG number.

Not saying it’s wrong, I’m just curious why. A carry over from beer making?

I'm curious which inaccuracies you are referring to in regards to SG.

How many of those winemakers started out using kits? I imagine a fair number of people here starting their winemaking adventure with kits. As such, all instructions talk about using hydrometers and measuring SG. That is the standard they are familiar with, and with some practice are able to know where a wine is at based on 1.XXX or 0.99X. Switching to Brix would require a new piece of equipment, learning a new "language", and having to deal with the correction factors necessary to get accurate readings.

There are advantages and disadvantages to each. It's up to each person as to which is best for their situation.

 

[sour_grapes]

I'm curious which inaccuracies you are referring to in regards to SG.

This statement was in response to me, wherein I had reminded us that "12.9 Brix" (on a hydrometer) during fermentation does not mean 12.9% sugar in the must, due to the confounding effects of the ethanol in the must. NorCal was just correctly pointing out that, due to the same effects, you cannot make a simple correlation between the SG and the remaining sugar.

(Of course, the SG itself is accurate, it is what a hydrometer measures, but it requires some work to relate that to the sugar left.)

I believe that is what you meant, @NorCal , but obviously correct me if I am wrong.

 

[FreddyC]

I use Brix. I've never like SG because it is less familiar to me. All my winemaking buddies also use Brix, but we all work exclusively with fresh grapes and not kits or fruit.

 

[Ajmassa]

I don't have to use SG or Brix. I've got a residual sugar meter, totally unaffected by alcohol content and only $12. It's actual sugar content in g/L. Accurate to the hundredth decimal place too.

 

[NorCal]

This statement was in response to me, wherein I had reminded us that "12.9 Brix" (on a hydrometer) during fermentation does not mean 12.9% sugar in the must, due to the confounding effects of the ethanol in the must. NorCal was just correctly pointing out that, due to the same effects, you cannot make a simple correlation between the SG and the remaining sugar.

(Of course, the SG itself is accurate, it is what a hydrometer measures, but it requires some work to relate that to the sugar left.)

I believe that is what you meant, @NorCal , but obviously correct me if I am wrong.

Yes, that is what I meant.