Hydrometer on Mead?

[ike8228]

I’ve always used my hydrometer for beer (it does say beer on it), but does it work the same for mead? Is there a conversion for the gravity reading for mead vs beer? I just did two small batches and this is my findings but they don’t add up.

One batch I had 124 Oz of water and 3.29/lbs of honey (swamp). This should be .968 gallons of water ratio for 3.39lbs/gallon. The standard of 35 points per pound should be 1.119 but I got 1.098 with the hydrometer. About a 2% difference.

300oz of water, 8.64lbs of honey (clover). This should be .781 gallons of water ratios to 2.88lbs/gallon. If you go by the standard of 35 points per gallon, this would be about 1.129, but I got a reading at 1.092. About a 3.3% difference.

Both were taken at about 85 Degrees F. Or is the 35 point system just not that accurate? Is it safe to go by the ‘beer’ gravity reader or does it not matter; gravity is gravity?

 

[Maylar]

Gravity is gravity. 35 points is an average, honey varies. Also be sure you've mixed it well and the honey isn't sitting on the bottom of the carboy.

 

[RM-MN]

I’ve always used my hydrometer for beer (it does say beer on it), but does it work the same for mead? Is there a conversion for the gravity reading for mead vs beer? I just did two small batches and this is my findings but they don’t add up.

One batch I had 124 Oz of water and 3.29/lbs of honey (swamp). This should be .968 gallons of water ratio for 3.39lbs/gallon. The standard of 35 points per pound should be 1.119 but I got 1.098 with the hydrometer. About a 2% difference.

300oz of water, 8.64lbs of honey (clover). This should be .781 gallons of water ratios to 2.88lbs/gallon. If you go by the standard of 35 points per gallon, this would be about 1.129, but I got a reading at 1.092. About a 3.3% difference.

Both were taken at about 85 Degrees F. Or is the 35 point system just not that accurate? Is it safe to go by the ‘beer’ gravity reader or does it not matter; gravity is gravity?

Hydrometers are calibrated for a specific temperature, usually in the 60's F. Measuring at 85F should give you an erroneous reading.

 

[dmtaylor]

My guess is your estimate of 85 F must be off. At 85 F you need to add 3 gravity points, so 1.092 becomes 1.095. But measured at higher temperatures it's even higher yet. If it was more like 110 F, it increases by 8 points to 1.100.

And maybe your hydrometer just got knocked cuckoo and needs to be recalibrated. Measure plain water at 60 F. What does it read there?

 

[bucketnative]

FYI, when determining %error for the gravity, ignore the 1, otherwise your percentages are off by roughly an order of magnitude. In your first example, your gravity reading was actually 20% lower than theoretical. Meaning, you should only look at the decimals:

%error = (meas. - theor.)/(theor.)

In your first case, you should have:

%error = (0.098-0.119)/(0.119) = -18% error

I believe your error may be down to improper mixing or it could be a really bad hydrometer.

 

[ike8228]

FYI, when determining %error for the gravity, ignore the 1, otherwise your percentages are off by roughly an order of magnitude. In your first example, your gravity reading was actually 20% lower than theoretical. Meaning, you should only look at the decimals:

%error = (meas. - theor.)/(theor.)

In your first case, you should have:

%error = (0.098-0.119)/(0.119) = -18% error

I believe your error may be down to improper mixing or it could be a really bad hydrometer.

I plan to check it with distilled water at 60-65F and see where it’s at. It should be at 1.000. If it’s ****, I’ll look at getting a new/better one.

 

[ike8228]

So my hydrometer broke today anyway, so there you go. I did get a reading before that happened in the batch I did today.

So today I estimated 1.102 on 14.698lbs in a 5 gallon batch. I used 512oz for 4 gallons of water. I measured 1.102 on the button at 70F degrees.

But I have a follow up question, when calculating honey/gallon, do you use lbs/water added or lbs/batch quantity. For example, in this batch if I divide lbs/5gal it’s 2.94lbs/gal, but if I divide lbs/water added (512oz or 4gal) it is 3.68/gal. I just want to know because I am trying to get my ratios correct for future batches when determining how much to add when making sweet vs dry.

 

[bernardsmith]

Not sure I fully understand the question. I assume (my rule of thumb): dissolve 1 lb of honey in water to MAKE 1 gallon and the honey raises the gravity of the water from 1.000 to 1.035. I am not weighing the water and I am not using ratios. If I added 2 lbs of honey to water to make 1 gallon total the gravity would be about 1.070. If I need a more accurate estimation I would measure with my hydrometer.

 

[ike8228]

Not sure I fully understand the question. I assume (my rule of thumb): dissolve 1 lb of honey in water to MAKE 1 gallon and the honey raises the gravity of the water from 1.000 to 1.035. I am not weighing the water and I am not using ratios. If I added 2 lbs of honey to water to make 1 gallon total the gravity would be about 1.070. If I need a more accurate estimation I would measure with my hydrometer.

What I’m trying to say is do you go by how much honey is in that gallon, or how much honey to water ratio. Is that honey part of the gallon or not when sayin Xlbs per gallon. My five gallon batch only had 4 gallons of water in it, but with the honey it’s 5. Is the amount of honey/gallon divided by 5 or 4?

 

[bernardsmith]

For the absolute gravity reading the volume is honey + water: the total volume in question is 1 US gallon and the amount of honey involved is 1 lb. 12 lbs of honey = 1 US gallon - so 3 lbs = 1 qt and so 1 lb = 1/3 qt. If you need ratios then qts : qts would work (1 gallon = 4 qts). Not sure I understand any "ratio" that involves weight in lbs and volumes in gallons but then I don't see the world mathematically.

 

[ike8228]

For the absolute gravity reading the volume is honey + water: the total volume in question is 1 US gallon and the amount of honey involved is 1 lb. 12 lbs of honey = 1 US gallon - so 3 lbs = 1 qt and so 1 lb = 1/3 qt. If you need ratios then qts : qts would work (1 gallon = 4 qts). Not sure I understand any "ratio" that involves weight in lbs and volumes in gallons but then I don't see the world mathematically.

Forget ratio. I have a 5 gallon batch. 4 gallons as water, the rest honey. 14.698. When calculating lbs per gallon. Do I use 5 or 4? Lbs per 4 gallons of water, or lbs per final volume (5gallons). Because I would think you wouldn’t divid the honey by itself. The honey IS part of the 5 gallons. Maybe I’m just way over thinking this.

 

[Drewed]

Yes you count the honey as part of the total. It is a ratio, but we are mead makers, not math guys. When I make mead, I use 3 to 4 pounds of honey to make one gallon of mead. I add the honey to the fermentation chamber, then add water to make the total volume one gallon.
In mead making, and "brewing" as a whole, when you speak of gallons, you are speaking of the total volume of a the batch. I.e. A one gallon batch, a five gallon recipe. Most recipes are scalable, so 3lbs of honey per gallon is 3lbs of honey to make a gallon, or 15 lbs to make a 5 gallon batch.
Start with the honey ( or some water to help the honey dissolve,) then add water until the batch volume is reached.

 

[bernardsmith]

@ Drewed - PRECISELY! yes!!! The total volume MUST include the honey. 3 lbs in 1 gallon (or 1 lb in 1 gallon) or whatever... But the total volume = honey PLUS water (or fruit juice etc).

 

[ike8228]

That’s what I’ve been doing but I don’t know why I got hung up on this this time around....too smart for my own good I guess [emoji51]

 

[Drewed]

That’s what I’ve been doing but I don’t know why I got hung up on this this time around....too smart for my own good I guess [emoji51]

Every once in awhile the brain sticks on something and you suddenly talk yourself into a circle. Tends to happen to me at the brew store! I'll come home with six things not on the list, but forget the yeast or the bottles that went there for

 

[bernardsmith]

Just proves that you pass the Turing test to show that you are human and not an automaton.