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Specific Gravity of Simple Syrup

I recently brewed a tripel and added a simple syrup (2lbs sugar boiled with 32oz water) about 4 days after the start of fermentation. When estimating my OG, should I assume the contribution is identical to adding 2 lbs of sugar to the boil or would it be lower to account for the water it was boiled in?

With only a quart of water and that much sugar I’d probably count it as a boil addition, maybe knock a few points off.

I would just add the gravity points contributed to the beer by the sugar, but recalculate the total volume to account for the added water. So if your batch was the standard 5 gallon size, add the gravity points for the 2 lbs. of sugar ( 46 points per pound per gallon, by my calculations ), divided by the total volume of beer ( 5 gallons, plus the quart of water you added ), plus the OG after compensating for the additional water ( OG * ( 5/5.25)). I’ll assume you can figure out the rest of the math from here. It’s not at all complicated, and I’m pretty sure I’m right in the equation I’m giving you.

[quote=“deliusism1”]I would just add the gravity points contributed to the beer by the sugar, but recalculate the total volume to account for the added water.[/quote]Out of curiosity I just did this in Beersmith, changing the final batch size to 5.25 from 5 with the sugar lowers it by 4 points.

I’m not suggesting that you don’t know what you’re doing with that program, but that result is impossible. It’s not a difficult equation to work out on a hand calculator. I’m about to crash out for the night, or else I’d do it myself and post the result.

Meh, I figure the OG between 1.080 and 1.083, with my just measured FG from 1.010 to 1.012 (9.3 brix). So my abv is somewhere between 8.6 and 9.3%. Sample tasted damn good. Now to cold crash with target tap no earlier than March.

Impossible? I mocked up a recipe with 12# of base malt and 2 # of sugar. A batch size of 5 gallons and 72% efficiency comes in at 1.084. When I increase the batch size to 5.25 gallons to account for the 32 oz of extra water it drops to 1.080.

But did you do 5.0 gal WITHOUT the 2 lbs. sugar?
Then compare it to a 5.25 gal batch WITH the sugar…

Yes, that’s definitely impossible. I don’t care what the software program says, that’s wrong. If you’re adding that much in the way of fermentable sugar, the OG must go up, even if you’re adding a quart of water. It’s just that simple. I’m not calling you stupid, but something is wrong with your program, or the way you’re using it.

I wonder if the program assumes a 72 percent efficiency in the sugar water, rather than adding the points directly (since there was no conversion to consider with the sugar)…I’m not at home to run it through BS 2.0, but I doubt Brad Smith missed that aspect.

I think there might be a little bit of confusion here. Using Beer Alchemy, I get a three point drop in OG in adding two pounds of simple sugar vs adding those two pounds with an additional 1 qt of water. My original inquiry was how does the water change the gravity of the simple syrup. In this case, you get three less points. The just sugar addition contributes 15 points of gravity, while the simple syrup addition contributes 12 points.

I’m pretty sure that this is because the simple syrup addition incorporates the water into the total volume of liquid in the fermenter, while the sugar is just a straight addition that does not add anything in the way of liquid volume. Any time liquid is added to the fermenter, the volume goes up and dilutes whatever fermentables are in there. What is the OG on this beer before you add the simple syrup? I think we can clear this up pretty quickly with that simple piece of info.

1.068 at pitching. I figure my actual OG to be 1.080, making my FG 1.012 and ABV 9.1%.

1.068 at pitching. I figure my actual OG to be 1.080, making my FG 1.012 and ABV 9.1%.[/quote]

9.1% ABV?? I think you’re mistaken on that figure. You would have to get 102 % attenuation from your yeast to get that level of alcohol, by my calculations, which is obviously impossible.

[quote=“deliusism1”]
9.1% ABV?? I think you’re mistaken on that figure. You would have to get 102 % attenuation from your yeast to get that level of alcohol, by my calculations, which is obviously impossible.[/quote]
Umm, no, I’m not.

http://www.brewersfriend.com/abv-calculator/

8.93%-9.49% is the range between the two different calculations (the latter number is supposed to be more accurate). I have noticed I get some variance depending on what calculator I use so I’ll just call it low 9’s.

[quote=“airlocksniffer”][quote=“deliusism1”]
9.1% ABV?? I think you’re mistaken on that figure. You would have to get 102 % attenuation from your yeast to get that level of alcohol, by my calculations, which is obviously impossible.[/quote]
Umm, no, I’m not.

http://www.brewersfriend.com/abv-calculator/

8.93%-9.49% is the range between the two different calculations (the latter number is supposed to be more accurate). I have noticed I get some variance depending on what calculator I use so I’ll just call it low 9’s.[/quote]

I’m not getting those values at all with that calculator. I’m getting about 8.1 % ABV with the values you’re quoting, and that’s with 79% attenuation, which is about as high as you can expect. I don’t know how you’re getting the range your quoting, unless you’re changing the rate of attenuation somehow.

I plugged the number into that calculator and got 8.9. I also did this quick equation I learned for the more beer kits and got the same

OG-fg x131. 1.080 - 1.012= .068 .068x131=8.908.

You have a couple things going on here. The addition of the quart of water (along with the sugar), decreases the OG by about 5% (one quart divided by 21 quarts) compared to what it would have been if you had just added the sugar, dry, to the boil. Also, each lb of sugar lowers the FG by 2-4 points (assuming the yeast performs to spec with the higher OG). And if you have a typical Belgian yeast, you can expect attenuation to be a bit higher, so I would project your FG to be 1.008 or even a bit lower. So 9+% ABV is certainly possible if your fermentation is healthy.

My fermentation was pretty rippin’. Repitched Wyeast 3522 slurry from a batch of Belgian Pale Ale, added 90 seconds of pure O2 prior to pitching, :blah:

It’s definitely got some alcohol in it. :cheers:

He said that his OG after adding the sugar was 1.080, meaning that his yeast would have to attenuate to the tune of 102% to get 9.1% ABV. What yeast on earth can do that, I ask? I’m pretty darn curious.

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