I’d like to learn how to control my brewing better.

Rather than having to treat my brew with chemicals so I can back sweeten, as most folks seem to prefer, I’d rather brew it to the desired FG.

From what I’ve read, I think this can be calculated out.

If I’m looking for a FG of 1.025 say, and am using a 14% yeast, then the OG would need to be 1.131 ((ABV/131)+FG)

This is all fine unless I want a lower ABV, because there doesn’t seem to be any way to stop the ferment at a specific ABV. Either the sugar runs out, or the alcohol kills off the yeast, or perhaps the PH does.

Are there yeasts that will give lower ABVs, like 10% say?

How do they make beer at 5%, do they have to back sweeten?

Is there some other way to accomplish this without treating, back sweetening, letting it settle again etc?

Yes, you are on tract.

Beer yeast are going to be the least alcohol tolerant. They will stop in the 10% range. I have not used it in a mead, but US05 may be a good choice.

Wine yeast will go to the 13-15% range.

And champagne to the 17-20% range.

The dry mead east says it’s 18% and the sweet mead yeast 11%.

There is a lot of info in this link.

Thanks.

I’ll start looking into yeast types.

My next batch, regardless of the ABV I end up going with, I’ll try and calculate the OG out so I end where I want without needing to back sweeten. Just think it’ll be cleaner, less handling etc.

Granted it’s not an exact thing, but with some tinkering, I think I should be able to get a set it and forget it kind of recipe I like (discounting the staggered feeding)

I looked over the formula for calculating OG on the link below, and I don’t see how to come up with the answer provided for the OG (Solving for Ct you’ll get…)

http://home.comcast.net/~mzapx1/FAQ/MeadOG.pdfDoes anyone know the calculation for Ct?

Hightest didn’t “show” some of his work. His math instructors might not be impressed. :shock:

See if this helps.

[quote]C1V1 + C2V2 = CtVt = (1.000)(64) + (1.417)(20.425) = CtVt

Vt = V1 + V2 = 64 + 20.425 = 84.425 cups (consistent units)[/quote]

(1.00)(64) + (1.417)(20.425) =Ct(84.425)

64 + 28.942225 = Ct(84.425)

92.942225 = Ct(84.425)

92.94225 / 84.425 = Ct(84.425)/84.425

1.1008851051228901391767841279242 = Ct

So the ending volume is 84.425 Cups (5.2765625 gallons) and an OG of 1.101

[quote=“Nighthawk”]Hightest didn’t “show” some of his work. His math instructors might not be impressed. :shock:

See if this helps.

[quote]C1V1 + C2V2 = CtVt = (1.000)(64) + (1.417)(20.425) = CtVt

Vt = V1 + V2 = 64 + 20.425 = 84.425 cups (consistent units)[/quote]

(1.00)(64) + (1.417)(20.425) =Ct(84.425) I get this- V1 + V2

64 + 28.942225 = Ct(84.425) First part is V1. Where did 28.942225 come from?

92.942225 = Ct(84.425)

92.94225 / 84.425 = Ct(84.425)/84.425

1.1008851051228901391767841279242 = Ct

So the ending volume is 84.425 Cups (5.2765625 gallons) and an OG of 1.101[/quote]

The (1) item is water. So the SG (C1) is 1.00. The V1 is a volume you control. Hightest decided to use 64 cups ( 4 gallons). You can use any volume you want.

The 28.942225 is the SG of honey (1.417 as quoted from the National Honey Board) multiplied by volume of honey. Again, use can use any volume (V2) you want.

[quote]What will the OG be if we mix 15 lbs of honey with 4 gallons of water?

• Let C1 be the SG of water (1.000), and V1 be the volume of water (64 cups) - there are 16 cups/gal.

• Now what about the honey? Well, the National Honey Board provides us this information. Honey’s SG is primarily a function of its moisture content and typically that is 18%, which equates to a SG of 1.417 (15% honey is 1.435). And so C2 = 1.417.

Now for the “hard” part. Our recipes are usually in lbs of honey. Yet, we need its volume. As if by magic, we know that a gallon of 18% moisture honey weighs 11.75 Lbs (also noted in Ken’s book, pg 89). So we know 16 cups of honey (1 gal) weighs 11.75 lbs. So if we use 15 Lbs of honey”

• The volume used is 20.425 cups [15 Lbs / 11.75 Lbs/gal * 16 cups/gal]. Thus, V2 = 20.425 cups[/quote]

With this equation you can raise or lower the OG and keep the final volume the same.

Or raise/lower the volume and keep the OG the same.

Using 2 different calculators, qbrew/BeerToolsPro, I get 2 different OG’s for a 5.28 volume and 15lbs of honey. 1.093/1.091

qbrew has 1lb of honey with a final volume of 1g being 1.042

BeerTools is 1.032

In qbrew, editing the ingredient has only a SG to edit.

BeerTools, there is a number of items to change. The moisture contend is set at 18.6. If I change it to 18%, the OG does not change.

Then there is a “OG (lb/gal)”. If I change the "OG (lb/gal) from 31.9oe to 35.5oe the numbers match. what this figure is I don’t’ know.

How each author came up with their calculations, …

Thanks NH, I get it now

Vt=V1+V2

Ct=(V1+(C2*V2))/Vt

My spreadsheet works

It was a fun exercise to go through.

Interesting that the 2 calculators are off like they are. Not enough to worry about when adding ~1qt to a beer. But it makes a big difference in a straight mead.

In defense of calculators, every production run of grain, and to a small extent each bag, will have a points potential variation.

And, will the honey be 18% water, or 19%?

Are we using 4 gallons of water or 4.25.

Everything is “a best guesstimate” .

:cheers:

Understand it’s a guesstimate.

Was thinking it would be nice to have the formula though, so I could use a desired FG to then calculate the OG I should have, and the actual amount of Honey needed to get that OG

Ct=(V1+(C2*V2))/Vt

Looks good to me. You just removed the C1 value because it is “1”. So it doesn’t affect the outcome.

If you add the C1 value back in, you have the formula for mixing 2 beverages and coming out with an estimate of the final product.

Ct=[(C1*V1)+(C2*V2)]/Vt

Ct= [6%*2g) + (8%*2g)]/4g

Ct= (12+16)/4

Ct= 7%