View Full Version : Mead calculator - courtesy of JamesP

01-24-2005, 01:54 PM
Hi all,

James has put together a nifty mead calculator for us to play with. I've got it up here: NEW LINK (http://www.gotmead.com/component/option,com_wrapper/Itemid,77/). Go play with it, and see what you think. Please post your impressions here, so James can see too.

Thanks James! Between you and jab (whose working on a nifty recipe database) we're going to have some *cool* toys to make our hobby more fun....


01-24-2005, 01:59 PM
w00t! Who doesn't love toys!

01-24-2005, 02:13 PM
I like it! Especially where it has default values for adding fruit.

A suggestion... I believe that honey is only 85 or 90 percent fermentables and so shouldn't the default sugar percentage number for honey reflect that?

Otherwise, it works swell! I used it to check out my numbers for my melomel I just racked onto additional honey and fruit. It came out with close enough numbers to what I had calculated manually to make me feel comfortable with what I had done...

Thanks for providing it!

01-24-2005, 07:31 PM

that's the sort of feedback I need.

Also, does the Target Gravity match what you actually measure with your hydrometer, for the amount of honey used - when you modify the "Sugars Content" to 85 or 90?

The sugar percentages for the fruit comes from info supplied by Dan McFeeley (http://www.gotmead.com/smf/index.php/topic,596.0.html)

The Assumptions & formulae used are as follows:

8 gravity points per pound of honey in 5 US gallons
BRIX = 220(SG-1) + 1.6
Baume = BRIX/1.8
%ABW (Alc by weight) = 0.8 * % ABV (Alc by Volume)
%ABV = 139.706 * SG - 140.219 (from linear solution of hydrometer table figures)
Temp correction for hydrometer (SG correction) = 1.313454 - 0.132674*T + 2.057793e-3*T**2 - 2.627634e-6*T**3
for 59F (15C)
C = 5*(F-32)/9
F = C*9/5 + 32
1 US Gal = 1.2 Imp Gal = 0.263963098 Litres
for honey: 1 Pound = 12 US Gal = 14.4 Imp Gal = 1.65345 Litres = 2.2046 Kg
The formula for calculating the SG from the Volume & Quantity of honey is:
Gravity = 1 + (Grav_Factor*Quantity)/(1000*Vol/5 US Gal) = 1 + (Grav_Factor*Quantity)/(200*Vol)
where Grav_Factor is the 8 gravity points per pounds honey in 5 US Gal

01-24-2005, 09:54 PM

I am so new to this that I am not a good one to ask. I will go play with it some more and see whether the results match my results or not....

But thanks again!

01-24-2005, 10:14 PM

I looks pretty good, and a very useful tool. I plugged in some numbers, and I'll keep track of how it matches up to my batches.

It may be a good idea to post up some additional instructions and/or examples on how to use the calculator for newbies and cover stuff like juice instead of fruit, added sugars, etc. It seems fairly straight forward to me, but I never assume that someone else will intuitively pick up on things.



01-25-2005, 12:52 AM
... and cover stuff like juice instead of fruit ...

From your experience, what is the relationship of sugar concentration of juices compared to the fruit?

I assume equal, but .... ?

01-25-2005, 01:07 AM
Just for a comparison, my blackberry puree was 8 grams of sugar per 125 grams of puree. I think I got 6.1% from the calculator, which is pretty close.

01-25-2005, 01:10 AM
Really I think they're pretty much the same or at least within 10% in my experience.

Of course I've bought frozen fruits from places like Costco and found that they have sugar added which kind of throws things off. I've also found that a lot of the fruit that is sold frozen is not fully ripe and does not have the sugar content that I would expect from fresh fruit. So it really varies. I think in fruit juices there are a lot of times when sugar is added.

There's no way to capture that in the calculator really. Just wondering if others have found that the sugar content in juice is within 10% of the fresh like my experience tends to indicate. I think I saw a chart around here somewhere. I'll take a look and post what I find.



01-31-2005, 01:52 AM
Another question:

For the calculated values, should the numbers right of the dedimal point be rounded (reduced) to only 3 or 4 digits, rather than the 14 or so currently displayed?

02-15-2005, 08:02 PM

Was playing with the calculator again today, trying to decide what to do about my blackberry wine that is stopped at 1.08. I noticed that raisins were not in the list of fruits...


02-26-2005, 05:57 PM
A suggestion... I believe that honey is only 85 or 90 percent fermentables and so shouldn't the default sugar percentage number for honey reflect that?From what I've been reading, honey can vary anywhere from 82% to 86% fermentables (sugars). I found some East Indian honeys in the 77% to 81% range.

02-27-2005, 07:18 PM
"An analysis of honey" (http://www.solorb.com/mead//danspaper.html) averages a value of 79.6% (is a typo in table 1 - should be 38.2% not 8.2% Levulose)

I was going to go with that figure - but you can put whatever figure you like in the calculator if you know exactly what your honey contains, it just won't be the default value ::)

The problem is to find an "average" value that people can use, and finding a "baseline" for all the calculations. There are a lot of formulae that give approximations, but what are the correct or more accurate formulae to use? ???

02-27-2005, 09:30 PM
Makes sense to leave it as a variable.

Now I have a question. Will you be writing instructions on how to use/read your calculator soon? Being totally new to the process, I can understand the elements I am looking individually in relationship to everything I've been reading but I don't understand how the current gravity works with the "Target Gravity". The target gravity seems to always read higher. I thought that given a "current" gravity" that the "Target" gravity would be the fermentation completed, lower value.

Please help me to read it?

My newest 4 liter batch is made using 2 lb (almost brown) old clover honey along with 1 lb 'fresh' clover honey (from Albertson's) for a total of 3 lbs. And since I like the taste of the last batch with lemon and tea, I added two medium lemons' worth of RealLemon lemon juice and a STRONG brewed tea. I used D-47 yeast rehydrated in 1/2 cup warm water. I started the batch last night about this time and it is already happily bubbling away.

My question is this: I just got my hydrometer today and decided to play with it. I got a "Current Gravity" of 1.101 and when I plug that into the calculator, I get a "Target Gravity" of 1.193.

Thank you very much for your help.

02-27-2005, 09:47 PM
The target is what you should get with the "sugars" you will add.
The "current" the value of existing must you are making additions to (default is SG=1.000 for water).

I have done a first draft of a help file, but am checking changes made to the calculator, so haven't sent them to Vicky yet.

02-27-2005, 11:05 PM
:D Got it! That's a huge help! Now that I know/better understand, it makes total sense.

So, is there a batch caculator out there for newbies to play with? Of course, it IS understood that knowing the initial SG is important to the FG ;D

02-28-2005, 01:39 AM
Well, not a batch calculator but I am in the process of writing a Recipe/Batch application. One of the features I hope to add is the ability to select (probably from a drop down list) the batch size you want and it should recalculate all of the amounts.

Unfortunately I can't give an ETA that this point. Was going along pretty well until I received to paying contract work. Now I know how Vicky feels!

I hope to have something usable by the end of March. Won't be pretty but it should work. After that I will work on making it pretty and adding enhancements.

03-28-2005, 09:09 AM
Just to make sure I'm talking "apples & apples" here:

If I want to figure out the % sugar content of a fruit juice in order to plug the value into the mead calculator, would I do the following calc based on the label info:

grams of sugar/253 x 100

1) the label lists grams of sugar per one 8 oz. serving
2) 8 oz. fluid is 253 grams (or so)

What about % sugar in honey. I don't have a commercial jar in front of me, but I believe they list grams per teaspoon. I can always assume 80 to 85%.

I'm just trying to avoid too high a starting gravity.

03-28-2005, 09:35 AM

Let's make this a bit easier for you to calc your starting specific gravity;
batch size is 5 gallons.
One pound of honey in a 5 gallon batch will raise the SG 0.008.

So, for a 3 pounds honey per batch, you'll get this SG: 1.120
That won't be the exact SG that you'll get from your honey as it varies slightly from year to year and batch to batch, but it's a close enough average that you'll be able to get real close with your SG based on honey alone.

03-28-2005, 10:39 AM
Thanks Talon:

I want to do a calculation with fruit juice and honey. I see from the calculator I will get SG = 1.12 based on the assumption that the sugar content of the honey is 100%. In the two 1-gallon batches I've made so far, I used 3 lbs. of honey and ended up with a very dry mead after primary. At the time, I didn't have a hydrometer to measure the starting gravity, or I would have known it was going to be dry.

I'm trying to figure how much fruit juice I can add to the primary (i.e. substitute for H20) without making the original gravity too high (> 1.14). That's where I see the calculator can come in very handy.

I see you are in Deltona. I am in Winter Park. Are you going to the Mead Gathering this Saturday in Sanford?

03-28-2005, 02:21 PM
I'll be there! *grins*
I may be tired from helping my mom move, but I'll be there, even I I have to drag myself up the stairs! *grins*

03-28-2005, 05:43 PM
I use the calculator now with every batch just to do a rough check before I start.

Thanks again James!

04-01-2005, 08:46 AM

I noticed from some of your other posts that you use the Oregon Fruit Puree's in some of your meads. How do you utilize the calculator for these? I see they come in 49 oz. cans. Does the label tell you grams of sugar per serving, or some equivalent data where you could plug the amount and % sugar content into the calculator to determine SG?

04-02-2005, 11:56 PM

I have been counting two cans as the equivalent of 1 gallon of juice up until now. With the blackberry, there was a grams of sugar per 125 grams of puree. When I plugged in the numbers to the calculator, the percentage ended up being roughly the same as the numbers on the can.

But to be more specific, I have just been considering the sugar content of the fruit as being residual at the end since I am shooting for semi-sweet to sweet meads. If my SG is around 14 percent ABV and the yeast goes to 13.5, then that little bit plus the fruit should leave it just about right.

05-06-2005, 08:28 AM
any chance of adding Maple Syrup for the additional sugars I tried to use it for my Maple mead and didn't find a option for maple syrup. It is a very useful tool I will try it for my other cyser and meads

05-06-2005, 08:32 PM
It may be already included in version 0.2 (which is waiting for Vicky to have time in her busy schedule to upload onto the net).

Version 0.2 has the honey at about 89% not 100%, and lines up the sugar and honey calculations to the SG a little better (hope I got it right :-\ )
I've added raisins and some other fruit also.
In fact I'm think there is Maple included, but not sure if it's syrup or what.

05-06-2005, 08:48 PM
It may be already included in version 0.2 (which is waiting for Vicky to have time in her busy schedule to upload onto the net).

Version 0.2 has the honey at about 89% not 100%, and lines up the sugar and honey calculations to the SG a little better (hope I got it right :-\ )
I've added raisins and some other fruit also.
In fact I'm think there is Maple included, but not sure if it's syrup or what.

Thanks JamesP, this is a great tool and I'm sure you put in alot of hard work .....Thank you ;D

05-08-2005, 07:45 PM
Nope - I missed including Maple Syrup in the utility :o

So I have now updated to V0.3 and added Maple Syrup (66% sugars) and Maple Sap (2% sugars), and sent this to Vicky.

05-08-2005, 08:53 PM
Nope - I missed including Maple Syrup in the utility :o

So I have now updated to V0.3 and added Maple Syrup (66% sugars) and Maple Sap (2% sugars), and sent this to Vicky.

Thats great thank you for your hard work ;D

05-08-2005, 10:47 PM
And I have updated that to the website. The main menu for the site now also includes the Calculator, as does an article on the main page.

Vicky - currently attempting to apply the new menu layout to all 1200+ pages.....

05-08-2005, 11:49 PM
Thanks, Vicky.

We appreciate what you can do in between the real paying jobs.

PS - The news item link on the front page doesn't seem to go anywhere at the moment.

05-09-2005, 12:50 AM
This may be helpful for those who infrequently access the net when mazing:

The calculator is self-contained - it is javascript in a html file.

So if you need it while not connected to the net, you can save the page to your PC, then access it off-line via a browser (opening the html file you saved).

06-16-2005, 10:11 AM

I use this tool every few days and so I wanted to post a thank-you and ask a question.

I plan to make a wine...
10 lbs. of sugar
1 half gallon can of raspberry puree
a few raisins and the yeast

Allow it to ferment partway then add
1 half gallon can of raspberry puree
and however much sugar is required for some ABV level.

I will likely start with 5 1/2 gallons and add another 3 quarts to the volume when adding the additional items. I want to use the tool to figure out how much sugar. Let's say I have a 14% ABV yeast and want to end up with 1.02 SG after completion. Will the tool handle this? I know I can plug the numbers in and get an answer, but does the tool handle the subtleties associated with the changes in volume due to the changes in batch size and such?

Thanks again,

06-16-2005, 08:30 PM
No, the tool doesn't specifically allow for volume changes, but . . .

Calculate it as if you added it all at once, to get the total volume, but then the additions can be made part way through, and the volume can change until you reach the full volume you calculated.

06-26-2005, 10:14 PM
I have been using the calculator. Good work, I love it.
I have noticed some quirks.
A bit of research on honey (http://www.fao.org/docrep/w0076e/w0076e04.htm) and it seems to be closer to 11.8#s per US Gallon.
Also, I noticed that the assumption of 12#s per gallon applied to maple syrup. Maple syrup with a specific gravity of 1.37 will be closer to 11.41#s per US Gallon.
something that has been confusing me is that if you choose say, Honey and set it to 1 gallon of honey, then select litres instead of a direct conversion it comes to 7.258 liters. 1 US Gal being of course, 3.785 L.
It doesn't seem to be a direct doubling of the correct value (it would be 7.570 L).

I actually notice that the assumption that 12#s = 1 gallon is consistent for all materials. For fermentables which you don't have a quoted value for, I would use a table of specific gravities to convert weight (say #s to kilos) to volume (liters to gallons). So, say, I ask for 7#s of blueberries and then ask it to convert to gallon. It would take the 7#s, convert to 3.17 kg, then look up the sugar content of blueberries. It can be as high as 15% when ripe. So we'll go with 15% sugar. The specific gravity of sugar water with 15% sugar is say... 1.07. 3.17 kg / 1.07 = 2.96 liters.
This is 0.78 gallons.

btw, the reason I just posted all that dribble is because I'm calculating some stuff for my blueberry mead...

So anyhow, I would suggest fixing at least the gallons to liters conversion (and any other conversions that are screwy... like 1 us gallon to 245.436 fl oz).

The calculator is great otherwise though.

06-27-2005, 10:57 PM
Thanks for the feedback.

It is based around the 12# to a gallon of honey, as you said.

I'll have to have another look at it. Don't hold your breath waiting, tho ::)

08-01-2005, 12:31 AM

Just another thanks. I use this thing every few days. It is a big help.

Thanks again,

08-01-2005, 02:27 AM
I will likely start with 5 1/2 gallons and add another 3 quarts to the volume when adding the additional items. I want to use the tool to figure out how much sugar. Let's say I have a 14% ABV yeast and want to end up with 1.02 SG after completion. Will the tool handle this? I know I can plug the numbers in and get an answer, but does the tool handle the subtleties associated with the changes in volume due to the changes in batch size and such?

Thanks again,


I had this same dilema and realized that the calculator wasn't taking this volume change into consideration. No offense to the calculator, its a pretty good tool. But I made an excel spread sheet that you can just plug some numbers into and it will calculate what the final %abv should be. What I have found that is interesting and now seems completely obvious is that if you add more liquid with a lower starting gravity than your original must, than the final %abv will be a little lower than if you didn't add anything at all. So what you want to do really is to match the S.G. of the new liquid to the original must. If you want the excel sheet just email me and I'll send it to you.

Good luck,


08-01-2005, 01:39 PM
I sort of like the way it doesn't take volume changes into consideration.
Although a check box to toggle it would be nice.

Don't mean to bug ya JamesP
But, grade A honey with solids of 81.4% (minimum) has a specific gravity of 1.4171.
Meaning 11.336#/US Gallon.
And honey with 85% solids has a SG of 1.4350, or 11.48#/USG
Maple Syrup has 66% solids and an SG of 1.32,
or 10.56#/USG

And, this is odd. The target volume box correctly turns 3.79L into 1USG.
But the additional sugars boxen are still doing the 1USG to 7.258L

08-01-2005, 06:55 PM
Keep the feedback coming, thanks.

I'm trying to get my brain around how to make the measurements match each ingredient. The problem is there is a mix of volume and weight in the options that the tool must be able to convert between. And the current method I use is wrong, because it is based on honey, which is different to water, which is different to .....

Most weight/volume conversions are for water. But how do you convert for fruit with seeds (except you remove the seeds, puree and convert between volume or weight of the puree, which is close to juice) ?


the blending utility will help in determining the outcome of mixing two volumes of differing SG - but like you say, it isn't integrated into the calculations. I'll add that to the list of possible improvements.

08-02-2005, 01:39 AM

I've attatched the Excel Sheet so that you can check it out for the formulas and stuff. I hope it helps. My spreadsheet doesn't take into account the temperature difference between the temperature that I measured the S.G. at and the temperature that it is supposed to be measured at. If its possible, can you help me out with that?

Thanks and I hope I can help,


[attachment deleted by admin]

08-02-2005, 03:07 AM
My source for SG temperature corrections is as follows (it is for 95F, which may be different to the calibration temperature of some hydrometers)

From http://www.brewery.org/brewery/library/HydromCorr0992.html

Posted to HBD #963, 9/7/92, by Christopher Lyons Following up on the specific gravity of water as a function of temperature.... The earlier equation was based on data for 50F-to-105F. Since the equation was from a polynomial fit, it should not be trusted for predicting SG outside this temperature range.

The data below was obtained using the "Handbook of Chemistry and Physics (CRC)", and is valid for a temperature range between 0 and 212F.

Temp (C) Temp (F) Density Correction relative to 59F
------- -------- ------- --------------------------
0 32 0.99987 -0.74
3.98 39.16 1.00000 -0.87
5 41 0.99999 -0.86
10 50 0.99973 -0.6
15 59 0.99913 0
18 64.4 0.99862 0.51
20 68 0.99823 0.9
25 77 0.99707 2.06
30 86 0.99567 3.46
35 95 0.99406 5.07
38 100.4 0.99299 6.14
40 104 0.99224 6.89
45 113 0.99025 8.88
50 122 0.98807 11.06
55 131 0.98573 13.4
60 140 0.98324 15.89
65 149 0.98059 18.54
70 158 0.97781 21.32
75 167 0.97489 24.24
80 176 0.97183 27.3
85 185 0.96865 30.48
90 194 0.96534 33.79
95 203 0.96192 37.21
100 212 0.95838 40.75

The correction term was computed relative to 15C (59F). It may be easily calculated
relative to any temperature. A third order polynomial fit to this data was also very good (R**2 = 0.999969):

Correction(@59F) =
1.313454 - 0.132674*T + 2.057793e-3*T**2 - 2.627634e-6*T**3

where T is in degrees F.

This equation should be good for the entire temperature range of interest

08-02-2005, 03:47 AM
Cool. Thanks a lot man. Just to clear things up though, if the temperature of the liquid that I am measuring is say 77 F, than you would actually only add .00206 to S.G., right? So if it was measured to be 1.091, then it would actually be 1.091+.00206= 1.093.

So, I was just thinking that if you assume that you measured the s.g. at the same temperatures in the beginning of the fermentation and then end, then when you go to calculate the % alcohol by volume than the correction shouldn't really matter because it will cancel out when you take the differences of he S.G.. However, if the measuring temperatures differ by more than 5 degrees F then the factor will matter.

08-02-2005, 08:39 PM
Yep, that's my understanding - measure OG & FG at the same temperature.

Usually measure at room temperature, or convert to room temperature if the must is warm/cold.

08-03-2005, 02:48 AM
Thanks for all your help James. I updated and attached the spread sheet to take the temperature of the liquid into account.

[attachment deleted by admin]

11-09-2005, 02:11 AM
Hi all,
I came to depend on the mead calculator in planning my batches but now I find myself at a loss. Persimmons are not in the calculator! I found a nutritional page that has persimmons sugar content at 12.53 grams/ 100 grams of fruit.
Any ideas on how to use this data in the calculator?


11-09-2005, 02:35 AM
Pick any fruit, and set the sugar content to 12.53 (%)

It is the value in the sugar content field that is used for the calculation.

11-09-2005, 02:55 AM
Thank you James,
I wasn't aware that the % sugar field was modiefiable. As it turns out, the calculator came up with the same numbers I had after calculating it *the hard way*.

Thanks again,

Old Dirty Belgian
06-01-2006, 05:16 AM
Where did it go? I had the page linked. And I can't seem to find this handy tool.

06-01-2006, 07:38 AM
Where did it go?

In the Main Menu on the left, go to Make Your Own Mead and then Mead Calculator. Easy as pie.

06-01-2006, 05:16 PM
Hey Sander, It would be easy as pie...

If the link lead to something other then a blank page!


06-02-2006, 02:30 AM
Strange ??? , no blank page here.

06-02-2006, 03:14 AM
Looks like this may be related to the additional security layered in for the Patrons Section. We'll get 'er fixed up wiki wiki!



06-02-2006, 08:45 AM
Aroo? Not being seen? I can see it as admin, and also not logged in.

Patrons, are you getting a blank page going to the calculator?

06-02-2006, 10:40 AM
Works great for me. Running it on IE 6.0.2900 SP2. View of the forum is fine as well, fitting perfectly.


06-02-2006, 10:57 AM
Very odd.

It came up this time, but when I started to enter data into one of the fields, got "Document contains no data". Before it wasn't there at all.

This worked fine last week.

Using the link from this thread, I get "There are no items to display"

It is loading today from the menu bar on the left.


06-02-2006, 12:31 PM
MUAHAHAHAHA...you haf discover my Master Plan to drive Tony nuts!

I follow you around the site, and when I see you going for the Calculator, I switch it off!

Vicky - cackling madly...

06-02-2006, 02:13 PM
I don't care what you do. I'll never go back to Windoz!

A friend once said, "You're so twisted, when you die they'll have to screw your corps into the ground"


06-02-2006, 02:30 PM
Looks fine here, running Seamonkey 1.0.1 on Windows 98SE.


06-02-2006, 06:16 PM
I just posted up a sticky message in this forum containing a link to a temporary version of the mead calculator.

Click here ( to give it a try.


06-03-2006, 11:45 AM
OK. Guys?


Making Mead/Mead Calculator goes HERE (http://www.gotmead.com/component/option,com_wrapper/Itemid,77/)


Why the hell do I make friggin' menus and hundreds of pages of CONTENT if y'all won't USE them? I've updated the access file so that your old bookmarks point to the new page....but its on the menu...


Vicky - working on a Saturday because y'all don't check MENUS

Old Dirty Belgian
06-03-2006, 07:57 PM
Ahh; that's an easy way of finding it.. I always had it linked in my favorites. That link is once again working .

07-01-2006, 09:54 AM
There seems to be something wrong with the conversions: according to the calculator 1 US Gal = 7.258 Litres :o ???

07-02-2006, 05:39 PM
Known problem. The problem comes from generalising the conversion between wieghts to volumes, based on honey.

It is based around 12 pounds of honey is approx 1 gallon => sg=1.088 in 5 gallons

When I update it next, I will be allowing for density of each item (fruit, honey, ...) which allows proper conversion between the weights and volumes.

For most things, it will give you a good ball-park figure.

10-18-2006, 11:17 PM
Can I request an addition to the mead calculator? Molasses is missing from the list of sugars. My bottle says it has 10g of sugar (though 14 of carbohydrates) per 22g.