10

You certainly can. This is, for example, how you use a pycnometer. But, it's a bit of work. Two major problems: 1) You need to find a way to measure volume very, very precisely. The scales are reasonably accurate, but it is unlikely that you own a volumetric device accurate enough. Your SG will be screwed by an entire point for every 0.1% margin of error. ...


9

It might be Brix or Plato, which are basically the same. To test, mix up a 10% solution of sugar: 10 grams sugar in 90 grams water. If the scale is Brix, your solution should read 10 at the calibration temperature. If the units are gravity points, it will read 40.


7

Your process sounds fine - it's the way you're using the hydrometer that's the problem. To estimate alcohol content, you need to take a reading at the start of fermentation. You cannot read the alcohol content from the hydrometer alcohol scale at the end of fermentation. The hydrometer cannot measure the alcohol content directly, but it can estimate how ...


6

You are absolutely correct. Unless something is dissolved into the liquid, or there's so much trub that the hydrometer is sitting on top of it, the reading will be unaffected.


6

Specific gravity measures density, which is mass/volume. If you measured the total mass of your system (3000g + 300g) you would have gotten 3300 grams, but the volume is not 3000 ml because you added the DME and it increases the volume of the solution. If the volume increased by 174 ml you would get 3300/3174 = 1.040 for the density. In other words, the ...


5

The biggest issue in doing that is that krausen will get stuck to both your hydrometer and your carboy walls. Even if you wait for the krausen to die off before dumping your hydrometer in, you will still have a bit of a hard time reading it through the krausened carboy walls... But hey, go ahead and try! That is the essence of homebrewing.


5

For the benefit you'd gain from leaving your hydro in there (maybe saving some volume as you won't take samples) I think it wouldn't really be worth your time as I imagine it would be pretty difficult to read without having to clean it off. Also having to open up your fermentor each time to take a reading exposes the wort to possible infection. I usually ...


5

They are both very accurate when used correctly. It's really best to use both Refractometer is only accurate for OG readings. Benefit is a few drops for sample instead of 100-200ml. This is very useful when doing several samples trying to hit an OG in the mash/boil process. You still need your hydrometer for fermentation gravity readings and FG. Though ...


4

EDIT: I'm not sure I realized it was 50 points we were talking about here, or just let my attention wander for a bit! Suspended solids can make a difference (see the comments), but you'd almost have to be measuring the SG of slurry for it to make that much of a difference! If the original recipe called for 2 cans of extract, and you used 3 then that's just ...


4

You've covered the two main likely causes, with stratification being the most significant cause of error. Another potential error is in the volume measurement - if this is out, then all the calculations to relate pre and post boil gravity will be out also. Related to that is the 4 percent shrinkage that happens as wort is chilled from boiling to pitching ...


4

Before doing any math whatsoever, be sure to check the packaging for the specific hydrometer you are using. When mine broke recently, I went back to my LHBS and purchased a replacement (same store, same shelf, same brand) not only does it have different directions (above vs below meniscus) but it also has a different calibration temperature. Once you're ...


4

Just add the difference. The error is probably due to the paper scale shifting. To get a non-linear error, the diameter of the stem would have to have changed. Also, you should add the error back before you make any temperature correction (although it likely won't make much difference).


4

Here's a different approach to answering your question. Another completely valid, and backwards way of asking your question would be to ask: "How did people know that a hydrometer was an indicator of the beer being done?" The hydrometer really doesn't tell you that your beer is "done". What it tells you is that the sugars have been converted by yeast into ...


4

If it was an extract batch, it's easier to calculate the OG than to measure it. If it was all grain and you know your efficiency, we can calculate it pretty closely from the recipe.


4

I haven't used a hydrometer in years. I think they are worthless and you waste a fair amount of beer using one. You can do a very close estimate of your alcohol content by just using only a refractometer. I used a similar formula when making wine and remembered it for using it with beer too. I won't post the formula here (it's at this website). I never ...


3

Even with champagne yeast, fermentation shouldn't take more than a couple of days to complete fully. At the eighteen day mark, what you're seeing is degassing of the cider, where residual CO2 from the fermentation is escaping the liquid, not fermentation. At this point, your cider has complete fermentation, and should be aged as necessary before being ...


3

If the trub is actually physically holding the hydrometer up, preventing it from moving down, then unambiguously: yes, the trub will render your hydrometer reading useless. If, on the other hand, the trub is suspended in the liquid, it is a mixed bag. Suspended solids will impact a hydrometer reading, but for brewers it is usually very minimal. The only ...


3

The only other thing I can think of that isn't in mdma's answer is that your hydrometer is miscalbirated. Check that it reads 1.000 in distilled water at the temperature that the hydrometer is calibrated at.


3

Refractometer that others mentioned here are very easy to use. Since there are many correction calculators available online, the error of reading won't be terrible. Seems that no one suggested the use of pycnometer. I believe it is most precise "tool" for estimating gravity. The way it works is similar to what @mboren described.


3

The Beerbug is simple on how it gets its SG readings. It uses a weighted buoy, or other contraption that sinks in the wort. then it reads how much it weighs, the lighter it is the thicker the wort. heavier it weighs, thinner or lower gravity of the wort...... If you look at these links, beerbug review 1 and 2 you can plainly see the weighted buoy ...


3

You can always measure the specific gravity of any liquid with a hydrometer, but unless you know the starting gravity (as in, pre-fermentation), the reading won't actually tell you much. This on top of the fact that the byproducts of a mixed fermentation (alcohol, acetic or lactic acid, &c) will all have different densities makes a hydrometer reading ...


3

Quick but not very helpful answer, I am pretty sure there is some sort of equation that can be used for this I am not sure where I have seen it. I am going to do some digging through some book and the interwebs for you and will update here if/when I find it. Found it, it assumes T is in C. SG(true) = SG(indicated) x [ 1.0 - 0.00025[ T(actual) - T(...


3

Which of these two tools is more accurate/precise in taking gravity measurements? Hydrometer. In my experiance. It could be my cheap refractometer but i've noticed some inaccurate readings and I therefore don't trust it completely. I use the refractometer during the boil and fermentation just to get a general idea, but always a final reading with a ...


3

you can predict ABV by using the yield calculation, Safcider gives 1% of ABV for 16.3g/l 1049 ~ 135 g/l therefore 135/16.3 => 8.2% ABV Or you can get more complex by looking through these equations, but that is overkill for a quick homebrew, unless like me you are a bit of a science/maths geek: http://realbeer.com/spencer/attenuation.html


3

It is called a 'wine thief'. This should be readily available in any homebrew shop. Possibly in several sizes and qualities even.


2

There is absolutely no way to guess a recipe's OG without knowing the particulars of the recipe. Likewise, suspended solids won't affect the reading by a significant margin unless they are actually bound to the hydrometer itself. There are several things that could effect a hydro reading. Did you add top-off water before you took the reading. If so, there'...


2

It looks like the alternative to lead weights in the bottom of a hydrometer is steel shot. You should be able to check the difference between the two with a magnet. Alternatively, if you have a blowtorch, lead has a far lower melting point than steel. Just be very careful of molten metal. I'd also suggest in the future taking a sample of wort and cooling ...


2

As others have suggested, a refractometer is probably the way to go. However, if you've just broken a hydrometer and want to get your SG right now, you should be able to use a scale. I haven't tried this myself, so I don't know for sure, but I suspect that the average kitchen scale will yield results that are less precise than a hydrometer. Given the mass, ...


2

The scale is sometimes called "Gravity Points" - it's the Specific Gravity value (1.xxx) without the "1." prefix. So, 1.010 is 10, 1.020 is 20,...1.100 is 100 and so on.


2

The original gravity reading was probably low due to insufficient mixing. Unless you stir the wort vigorously for a good while, it will stratify with sugary wort at the bottom and thin wort at the top. See this question for more details about why your starting gravity might be low. The final gravity reading is probably correct. Did you taste the beer ...


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