Hello, already working on my own calc...

[HomeBrew]

Hello, I have yet to start my first homebrew but I have got 90% of the equipment and powders.

I'm still finding conflicting info on how much sugar creates what ABV.

I worked out my hydrometer scale matches up with the 17g of sugar per liter that's advised to add each 1% of ABV.
I made a spreadsheet that calculates it. If I put 4L of juice in the calc and the sugar that's already in the juice, then tell it I want 18% ABV, it's telling me to add 797g of sugar. I setup the calc to use the 17g sugar per liter for 1% ABV rule.

That 797g is nearly the same as the 800g I have often seen in wine making guides - but won't that produce an ABV more like 12% or 13% when added to 4L of juice?

I have seen a post saying 4.5L of juice needs 1200g sugar adding to achieve 18% but, that's more like 37g of sugar per liter once the 480g already in the juice, is factored in. My calc says to add 900g to 4.5L to create an ABV of 18% (1377g sugar total) so it's quite far short of the 480g +1200g I have seen elsewhere. Plot thickens!

Once I do a hydrometer reading before and after I'll tweak the calc. The yeast being used is a super "high alcohol" one, but it's not turbo or anything.

The calc:

 

[BigDaveK]

First a clarification - beer is brewed, wine is fermented.
I use a slightly different approach. One pound of sugar (453 gr) will raise the specific gravity of a gallon (3.78 l) approximately .040. Three and half pounds of sugar (1587 g) will raise the specific gravity to around the target of 1.140. The amount of sugar I actually use, though, depends on my SG measurement. "Close enough" measurements are good enough for me.

Keep in mind that fermentation is incredibly complex and beautiful and depends on so many factors like pH, temperature, yeast strain, and alignment of planets. Too much sugar all at once can possibly adversely affect the yeast. "Glucose repression" will affect enzyme production the yeast need to metabolize the various sugars and lead to a "stuck" fermentation. Consider multiple additions of sugar rather than one.

Personally I like to keep things simple and fun. It's easy to overthink. Been there.

Welcome to WMT! Good luck and have fun!

 

[HomeBrew]

Cheers Dave I'll just try with 800g in 4L and see what's what after 2 weeks.

 

[BigDaveK]

I suggest you ignore the calendar when making wine. I take SG measurements every day as part of my routine. Some ferments are faster than others. I've had a couple bone dry, SG around .990, in 6 days!

 

[HomeBrew]

Luckily I will be putting it in a room that doesn't fluctuate much in temperature and is around 22°C, day and night. Can results vary even if you use the same yeast/nutrient/juice from batch to batch?

Dave, what about returning the tested juice back to the container, never do it? If it's tested every day I'd be taking a lot out over 2 weeks if I was throwing away the tested juice!

 

[cmason1957]

Luckily I will be putting it in a room that doesn't fluctuate much in temperature and is around 22°C, day and night. Can results vary even if you use the same yeast/nutrient/juice from batch to batch?

Dave, what about returning the tested juice back to the container, never do it? If it's tested every day I'd be taking a lot out over 2 weeks if I was throwing away the tested juice!

Not Dave, but I'll give the answer most of us do. Sanitize your testing tube and your hydrometer, return the juice. As home winemakers we don't (well hardly ever) make enough to throw away the samples.

 

[BigDaveK]

Luckily I will be putting it in a room that doesn't fluctuate much in temperature and is around 22°C, day and night. Can results vary even if you use the same yeast/nutrient/juice from batch to batch?

Dave, what about returning the tested juice back to the container, never do it? If it's tested every day I'd be taking a lot out over 2 weeks if I was throwing away the tested juice!

The yeast can handle slow fluctuations in temperature. It's the sudden changes that can really mess them up. 22C is a good temperature. I've read lower temperatures lead to better extraction of various wine qualities so I'm testing that right now. My basement is 58F (14C). Yeast give off heat while working and the must is 61F (16C) and my ferment are robust.

@cmason1957 gave you a good answer. You're asking a lot of the same questions that went through my head. I'm guessing you probably have more. Well, this is certainly a great place for answers!

 

[sour_grapes]

As far as the results of your calculator: You can try calibrating your results against this extensive tool: FermCalc

 

[HomeBrew]

Cheers. I did look at that FermCalc last night and thought it was way too technical for me

I just started off a few test liters of orange from concentrate, the starting SG was 108 and the PA about 17.3%. That'll do

 

[sour_grapes]

Cheers. I did look at that FermCalc last night and thought it was way too technical for me

I just started off a few test liters of orange from concentrate, the starting SG was 108 and the PA about 17.3%. That'll do

What was the SG? 108 does not make any sense. Did you mean 1.080, or perhaps 1.108? Neither of those has a PA of 17.3%.

 

[HomeBrew]

That calc I made in Excel says:
Alcohol Aim: 18%
Sugar per liter: 306g

If I type 17.3% as the aim, in my calc it comes out at 294g per Liter

Very close to what the hydrometer says...

Hydrometer:
SG: 1.108
PA: 17.3%
Sugar per liter: 295g

All of those are lined up, using this hydrometer:

 

[wood1954]

Hello, I have yet to start my first homebrew but I have got 90% of the equipment and powders.

I'm still finding conflicting info on how much sugar creates what ABV.

I worked out my hydrometer scale matches up with the 17g of sugar per liter that's advised to add each 1% of ABV.
I made a spreadsheet that calculates it. If I put 4L of juice in the calc and the sugar that's already in the juice, then tell it I want 18% ABV, it's telling me to add 797g of sugar. I setup the calc to use the 17g sugar per liter for 1% ABV rule.

That 797g is nearly the same as the 800g I have often seen in wine making guides - but won't that produce an ABV more like 12% or 13% when added to 4L of juice?

I have seen a post saying 4.5L of juice needs 1200g sugar adding to achieve 18% but, that's more like 37g of sugar per liter once the 480g already in the juice, is factored in. My calc says to add 900g to 4.5L to create an ABV of 18% (1377g sugar total) so it's quite far short of the 480g +1200g I have seen elsewhere. Plot thickens!

Once I do a hydrometer reading before and after I'll tweak the calc. The yeast being used is a super "high alcohol" one, but it's not turbo or anything.

The calc:

Just go to Vinolab and use their calculator , very simple

 

[HomeBrew]

Cheers folks. I know these online calcs will be correct.

I might try to tweak the Excel file to match what those show, I always like having an offline version.

Having another look at FermCalc...

EDIT: OK it's making sense now I'm on the right tab. Quite daunting at first!

 

[sour_grapes]

That calc I made in Excel says:
Alcohol Aim: 18%
Sugar per liter: 306g

If I type 17.3% as the aim, in my calc it comes out at 294g per Liter

Very close to what the hydrometer says...

Hydrometer:
SG: 1.108
PA: 17.3%
Sugar per liter: 295g

All of those are lined up, using this hydrometer:

I cannot, of course, see your hydrometer. However, if the SG = 1.108 mark lines up with the PA = 17.x% region, then it is wrong. I would either get a different hydrometer or just never look at the PA section. (You can check if tap or distilled water gives you something close to SG =1.000 to make sure the hydrometer is basically okay, but I doubt that is a problem.)

 

[vinny]

Been there.

YA, like 2 days ago. I saw you peeking into that rabbit hole again!

 

[BigDaveK]

YA, like 2 days ago. I saw you peeking into that rabbit hole again!

Point of clarification, I'm already in the rabbit and - for better or worse - far past the point of no return. You saw me peeking into one of the many SUB-rabbit holes.

Sometimes I feel like I'm in a game. Instead of finishing I just advance to the next level. Good thing the game is a lot of fun!

 

[HomeBrew]

The hydrometer reads 1.002 in cold (5°C) filtered water. Since it would float even higher in water at 20°C then yes it's not right. I need to test it properly in water at 20°C to see.

EDIT: I did test it in 20°C water and the level where it reaches including meniscus effect is at exactly 1.000. If that's right then maybe I can take the start reading of 1.108 as accurate after all, even if the potential alcohol and sugar/L scales are off.

All the way down the scale, the numbers don't match with what FermCalc says.

On the (offending? ) hydrometer it's like this:

5% ABV = 85g Sugar/L = 1.030 SG
10% ABV = 170g Sugar/L = 1.062 SG
15% ABV = 252g Sugar/L = 1.094 SG

This table I found has lower ABV at those SG levels, more like 3.7%, 8.0% and 12.6%. That's showing sugar grams in a US gallon, so would need diving by 3785.41 to get liters. I might just type out that table and swap gallons to L so I can see what's what.

FermCalc at those SG levels says 4%, 8.4% and 12.7%.

So the hydrometer seems to be encouraging me to add less sugar than is needed!

Anyway I keep tweaking the calc I made. I didn't realize dissolving sugar into liquid doesn't change the volume of liquid (by any amount that matters) so I took all of that out of the calc. It doesn't account for anything lost to sediment either because that would throw off other calculations like what each bottle of wine would amount to in pints of beer at 5% (the only way I can truly know what I am drinking lol).

The calc is still based on the hydrometer so it's still wrong but it's just a case of tweaking it a little, after the final SG is known at the end, or I'll tweak it now.

 

[HomeBrew]

After only 2 days 7 hours, this has fermented way faster than I imagined it would. There was a lot of activity today (day 2) with little tidal waves of bits whirling around. I'm using a supposed "super" yeast, for high alcohol, but it's not a fast/turbo yeast. The juice certainly smells of alcohol now!

I tested it and put the numbers in FermCalc:

Initial SG reading: 1.1066 (adjusted for temp)
SG reading after 2 days 7 hours: 1.0210

That is a lot of progress in 2 days considering I was thinking it would take 2 weeks to finish. Maybe after another 4 days or so it might be fully dry... or does it just not work like that and the last part takes 12 more days to get to complete dryness, even after a start this fast?

I only need to screw the caps on for 2 or 3 mins and it's creating gas so it's nowhere near the end, I hope. FermCalc says that SG difference equates to 11.5% ABV at the moment.

 

[sour_grapes]

That is, indeed, a fast fermentation. But not ridiculously so. Depending on temperature, I would have expected that to take 3 or maybe 4 days. The fermentation does indeed slow down towards the end, but rarely would it take two weeks. Carry on!

 

[HomeBrew]

3 full days and I just tasted it... rocket fuel! It's 3/4 of the way up the yellow band on the hydrometer.

SG is down to 1.002 now. According to FermCalc, from where it started it's at about 14.2% ABV now. Crazy that it's only taken three days. If I leave it to get to 0.998 that's 14.8% and if it can get to 0.996 that's 15.1%. I'll probably leave it to settle another day and just bottle it without even testing it again.

It's sweeter than I thought it would be, but not too bad. It shows that I added maybe 10% too much sugar though... hmmmm.