A Couple Beginner Questions

[reeflections]

( I was 27 when that song came out you want to compare "Oldness?"

Me too. These young whipper snappers don't know what old is.

 

[wpt-me]

If that's the case I was 36 in 76!!

Bill

 

[winemanden]

Babes in arms I was 43 in 76. At least I think so, or was I 76 in 43. Hmmm, I'd better check that.
Consulted the Oracle, she says I was 43.

Brix or SG. It doesn't really matter. Blindly following a recipe without checking is definitely NO.

 

[BernardSmith]

A gravity of about 1.088 is a Brix of about 20 (or 1/5 of the solution is sugar, Brix being the percentage of sugar in solution). Commercial wine makers tend to use Brix and home wine makers tend to use SG. I assume that the commercial wine makers adopted Brix because when you are checking grapes for ripeness and you squeeze a grape or two from a variety of bunches onto the screen of a refractometer you are far more interested in the amount of sugar in the grapes than you are in the density of the must and if your target is a harvest of grapes with about 20 -25% sugar then you might continue to use Brix as your scale for the duration. Home wine makers tend to buy grapes already harvested or buy pressed juice (or perhaps frozen grapes) so the first tool we pick up is more likely to be an hydrometer and we stick with SG for the duration... at least that is my thinking.

 

[winemaker81]

I agree with @BernardSmith's comment on refractometers vs hydrometers.

The commercial growers I knew cared first about the percentage sugar, and the brix scale gives that with no translation. For field testing before picking, they only needed to squeeze 1 grape to get a reading, and they might spot check several vines in a row. Using a hydrometer wastes a lot of fruit and takes a lot more effort, so the (at that time) relatively high price of a refractometer was fully justified.

Besides, we can add 3 additional factors why home winemaker use hydrometers:

1) Cost. In the late 80's/early 90's a decent quality refractometer ran $125 USD. In today's money, we can at least double that cost. In contrast, my hydrometer cost $4.75 USD. I almost purchased a $75 refractometer, but was told to not waste my money.

Today? A hydrometer is $13 and a basic refractometer is $33. [I don't currently have a reason to not buy a refractometer.]

2) Accuracy of readings. Look at your triple scale hydrometer -- SG is a finer scale than brix, so a home winemaker can get a more accurate reading without guessing.

3) Usefulness during fermentation. As ABV increases, the accuracy of the brix reading becomes less accurate. For fermentation, we want to know how far along the ferment is and when it is done, and the hydrometer is (IMO) a better tool for that job.

I'll add another reason:

4) Convention. Years ago books were written using the hydrometer as that is what home winemakers had. This advice has remained the same simply because no one as challenged it.

 

[BernardSmith]

I gotta agree with many of your points, Winemaker81, except one. The idea that an hydrometer is more "accurate" is unlikely. That the markings may SUGGEST accuracy is not the same thing as the instrument being accurate. First, it needs to be placed on a perfectly flat and horizontal. Your table is flat but is it in fact perfrectly horizontal? Could be but I doubt it. You need to read the scale with the line being at eye level. Do you always kneel down to read the scale? The liquid needs to be gas free and at the temperature for which the hydrometer was calibrated. Do you always completely degas the wine and account for the temperature of the room? Then there is the problem of the scale itself. Each line is two points of gravity. So, at best the accuracy is to one point (plus or minus a half point). And then there is the use we make of this instrument. It measures density, not alcohol. And we convert the density by subtracting the current reading from a previous reading (the first one) - so we have two relatively inaccurate readings to which we apply a formula that approximates the amount of alcohol in solution. Of course, many folk assume the accuracy of this tool and their ability to use it to state that their wine is not at say 12% ABV but 12.25 % ABV which suggests an accuracy of 1/100 of 1%... Sorry, but my guid Scottish skepticism finds that as likely as unicorns cavorting in my basement as I type this.
.

 

[winemaker81]

@BernardSmith, the table doesn't need to be perfectly horizontal. The surface of the wine will be level, regardless of the table. Besides, I use a Fermtech wine thief, which I hold at eye level, swinging between my fingers so it's as upright as gravity will make it.

I do look at the hydrometer reading at eye level, even when using a hydrometer jar. Until you mentioned it, it had not occurred to me that anyone would do otherwise.

Sure, the person's ability to correctly read a hydrometer is important, but with all the primers on reading hydrometers, I'll assume they can until proven otherwise. A person's ability to correctly conduct a test has nothing to do with that test being an accurate test.

Yes, I degas the wine when checking during fermentation. Yes, I adjust for temperature. For my hydrometer that is 1 at 70 F and 2 at 77 F. In my cellar in the winter the temperature is 58 F, so no correction required.

The scale for SG is finer graduated than brix, so if anyone is guessing, they'll guess better on SG.

The only 2 readings that need to be accurate are first and last. In both cases the liquid is degassed. All readings in between are a barometer of how far along fermentation is, and if the reading is off by a point or 3, it doesn't matter. If someone wants an accurate reading during fermentation? Cool. Conduct the test correctly.

I didn't mention calculating ABV, but as I said, the first and last readings are accurate if performed correctly. From those readings a reasonable ABV can be calculated.

The bigger question regarding ABV is if the right formula is being applied, as the constant in the ABV calculation changes depending on the ABV level, e.g., I know of at least 4 formulas that depend on where the ABV is between 3% and 18%. A graph of the ABV is an uneven curve, and I've yet to find a single equation that can solve it.

 

[Raptor99]

I mainly use my refractometer because I only need a few drops of wine for testing. That makes it simpler to use. As a bonus, my refractometer automatically corrects for temperature.

Once fermentation has started, I use an online calculator to give me the SG. I can also use an online calculator to figure out the ABV. I am not overly concerned with calculating ABV precisely. If it is within 1-2% ABV that is good enough.

 

[sour_grapes]

I think @BernardSmith 's and @winemaker81 's discussion could be made more concise by saying that, IMHO, Bryan simply meant to say "more precise," not "more accurate."

 

[bstnh1]

Brix??? I have a lot of those in my sidewalk! Sweet!

 

[justsipn]

Hmmm....going on day 5 since I pitched the yeast. No visible fermentation.

 

[justsipn]

If you can't deal with decimal points, wine making might not be for you. ( I was 27 when that song came out you want to compare "Oldness?"

Well....she was a math tutor in college, so I think we are good there. Reading hydrometer though.....

 

[winemaker81]

Hmmm....going on day 5 since I pitched the yeast. No visible fermentation.

what is the SG? Has it changed? If not, I'd rehydrate another yeast packet and jump start it.

 

[justsipn]

what is the SG? Has it changed? If not, I'd rehydrate another yeast packet and jump start it.

We are going to check that. Problem is, I don’t have more yeast.

 

[winemaker81]

We are going to check that. Problem is, I don’t have more yeast.

Dang! How warm is the area the must is in? If you can get the temperature up to 80 to 85F, that may help. Are you stirring at least daily? That can help as well.

 

[justsipn]

Dang! How warm is the area the must is in? If you can get the temperature up to 80 to 85F, that may help. Are you stirring at least daily? That can help as well.

I just remembered that I have a friend who might have some yeast.

temp is constantly 68 degrees.

 

[winemaker81]

temp is constantly 68 degrees.

Warm it if you can. Can move it into a small room (bathroom?) with a quartz heater or something similar? Even a few degrees may help.

I have fermented white kits in the winter at 58 F. It works, but each time it took 3+ weeks to finish.

 

[justsipn]

Warm it if you can. Can move it into a small room (bathroom?) with a quartz heater or something similar? Even a few degrees may help.

I have fermented white kits in the winter at 58 F. It works, but each time it took 3+ weeks to finish.

Added more yeast and moved it to 75 degrees.

 

[BernardSmith]

IMO, adding more yeast to a stuck or stalled fermentation is not always the best approach. A better approach is to turn that process on its head and make a starter of say, 1 cup with the new yeast and keep doubling the volume of the starter with the problem wine. If there is a systemic problem with that wine "diluting" it with active fermentation in the starter may neutralize the problem. If it doesn't you will see exactly at what point the yeast in the starter cannot ferment any more of the wine that was stalled /stuck and that may be for a variety of reasons. Simply adding more yeast to what may be a real problem with the wine may kill the second batch of yeast. Of course, if the problem is not systemic (eg it was too low a temperature - and not preservatives in the must; too acidic a must; etc) then upturning the process does not create a problem although it does mean that it will take a few days before the entire batch will be added to the starter.

 

[justsipn]

Added the second packet of yeast on Saturday evening and just last night started seeing some fermentation activity. Hopefully it goes well from here.