I have 1.75 liters of 100 proof vodka with zest of 28 lemons in it that has been steeping for six weeks. I am going to add simple syrup to make limoncello. My target is 30% alcohol. Do I calculate the amount of simple syrup to use based on the amount of water, or based on the total volume after the sugar has been added?
Add 1170ml of syrup. That gives you 2920ml of liquid, of which 875ml is alcohol, for a total of 29.9% alcohol.
Simpler, 875ml (starting amount of alcohol) divided by 30% gets you 2916ml total volume.
Remember your high school algebra.
[total volume] x [alcohol%] = [volume of alcohol]
rearranging it:
[volume of alcohol] / [alcohol%] = [total volume]
so:
875ml / .30 = 2916
I’m confused how this could even be a question, unless you are thinking that total volume wouldn’t include the sugar? I note in cooking shows that, for baking at least, sugar is usually considered to be a liquid ingredient because of the way it combines with other liquids.
However, the zest of 28 lemons has some volume, does that get strained out at some point? As a solid, it probably shouldn’t be counted.
I ignored that part of the question. Even now, when I’m actually giving it more thought. There’s too many missing variables. Since the OP used the volume 1.75l, my guess is that it’s a bottle of vodka plus the zest. As opposed to the zest plus the vodka being 1.75l.
Well, the OP’s question seemed to be whether the volume of sugar in the simple syrup should be included as part of the calculation. Your answer was, implicitly, yes. I was just trying to make that explicit, and we were writing at the same time.
You’re right, I misread that part. I would say yes, count the sugar. It’s part of the volume, it’s going to dilute the final product further, so it should count. Make/buy the syrup then measure and add it like any other liquid.
If you make SS from scratch you’ll find the volume of pure water + volume of sugar < combined volume of both once dissolved.
So mix up or buy enough SS that you can add 1170ml of the stuff per @Joey_P’s good calcs.
As a totally pragmatic (although more Cafe Society style comment) I’d advise starting with the above mentioned calculation, but hold off on about 100 mL or so. We have unknowns about how much flavor has transferred from the zest, and how much alcohol may be lost when discarding the solids (minimal likely, but not zero). Once you have that initial quantity of syrup added, taste it.
It may be that the final product/taste you want is better served (heh) by less syrup than your initial calculations, and it’s of course, easy to add more, extremely difficult (dilution and nearly starting over) to eliminate.
But since this is FQ, it would probably be worthwhile to do a detailed evaluation of the actual ABV of the solution post filtration of the solids and pre-syrup. I looked this up from when I was experimenting with making mead (epic failure), as it was mentioned by a friend.
The Spirit Indication Test
The most accurate method available to most home meadmakers to calculate alcohol by volume is the Spirit Indication Test. This method involves boiling a known sample of mead (wine or beer) to remove all its alcohol, reconstituting the solution to the original sample volume, and then comparing the SG of the two samples to determine the alcohol by volume.
These steps are defined below:
- Measure the SG of the finished mead.
- Measure 250 mL of the finishedmead (wine or beer) with a graduated cyclinder and pour into a flask, beaker, or pot that can be boiled.
- Boil the mead to half its volume. As alcohol’s boiling point is less than that of water, all of the alcohol in the mead will have evaporated.
- Reconstitute the sample to its original volume, 250 mL, using distilled water. Distilled water has an SG of 1.000, so we can ensure that the only changes to SG from the original sample to the final sample are the reduction of alcohol and replacement with water.
- Calculate ABV using either the table available here, or with an equation presented here.
Which is a great experimental FQ-style technique, but you’re loosing 250mL in the evaluation, and will still probably have unknowns if it’s overboiled and additional water is added to the evaporated alcohol.
The lemon zest gets strained out.
I’ve never been clear about alcohol by volume… Does 30% ABV mean that you start with 3 volume-units of alcohol and 7 volume-units of other liquids, or does it mean that you start with 3 volume-units of alcohol and end up with 10 volume-units of beverage? They usually won’t be the same thing. Which is why chemists usually prefer to measure by weight (or by moles), rather than by volume.
Not sure if this is what you’re getting at, but alcohol and water mixed together take up less space than they did when separate. I think this makes a precise calculation complicated because it must account for this space-saving behavior. Perhaps you’d need some mathematical expression or approximation for the behavior, to be included in the calculation.
Yeah, that’s what I mean. You can still work with it, so long as you’re clear how you’re defining “by volume”. If you want 10 volume-units of final product, then you pour your alcohol into a 10-unit container and add your other liquid until it’s full. If you want 7 volume-units of the other stuff, then you measure that out, and then mix them together and get whatever volume you get.
Wikipedia says it’s the latter:
Thus, alc/vol is not the same as volume fraction expressed as a percentage. Volume fraction, which is widely used in chemistry (commonly denoted as v/v), is defined as the volume of a particular component divided by the sum of all components in the mixture when they are measured separately. For example, to make 100 mL of 50% alc/vol ethanol solution, water would be added to 50 mL of ethanol to make up exactly 100 mL. Whereas to make a 50% v/v ethanol solution, 50 mL of ethanol and 50 mL of water could be mixed but the resulting volume of solution will measure less than 100 mL due to the change of volume on mixing, and will contain a higher concentration of ethanol.
Note that ABV = alc/vol. It’s also defined at a specific temperature (20 C).
I there something special about the 30%? I would dissolve the sugar in water first and then add it to the vodka based on volume. I made lemoncello in the past that way to get something like 33% alcohol by using 100 proof vodka and half it’s volume in sugar dissolved in water. Then I steeped the lemon in the mix. Worked well enough, nobody complained.
Just a target based on a bottle of commercial limoncello I have. I don’t mind going higher.
I’ve always roughed my simple syrup/alcohol ratio because you can never tell how tart the lemon zest is until you macerate it. I’ll bottle my limoncello tart and strong, because those can be easily fixed by whomever is drinking it. Weak and too sweet can’t.