help a total noob out... how do you read hydrometers?

I did a reading on my stout... I have a #3001 BEER and WINE HYDROMETER (how its labled if that helps)... specific gravity is reading 2 dash marks below 1.000 4 dash marks below the 1.000 is the number 10 and every 4 dashes the number goes up another 10 so... 10, 20, 30 etc... all the way up to 100 and then restarts the count. If I follow the line over from where it was floating when I took my reading (2 dash marks below 1.000 its in the 1 bracket as far as alcohol precentage goes?) Do I need to divide? the wifes a math teacher lol and says if you divide it should be around 4% but not sure... both of us dont really know how to do hydro readings... (well at all so thats why I come to you guys for support lol)

i guess I answered my own question:

How to Read a Hydrometer
Submitted by: Bob Zormeir

Hydrometers are calibrated for readings at 60o but the adjustment between 60o and room temperature is minimal. To make your readings (and your ABV calculations) consistent the main thing is to always measure at the same temperature. To adjust the specific gravity reading for temperature differences, add +0.001 if you're measuring at 70o instead of 60o. Adjust by +0.002 at 77o. Adjust by +0.003 at 84o. Adjust by -0.005 at 50o. If want to just measure the alcohol, but you don’t care about the precise alcohol level, adjustments for temperature fluctuation is an area that easily lends itself to the "Relax, don’t worry, have a homebrew" rule.

Before measuring, make sure both the hydrometer and hydrometer jar are clean. Hydrometers are made of rather thin glass, so exercise due caution. Strangely enough, even fingerprints on the bulb can theoretically affect the reading you will get. Make sure you wort is also clean and free of hop particles, etc. Pour the wort carefully into the hydrometer jar to avoid bubbles, then stir gently to release any existing bubbles.

Carefully lower the hydrometer into the wort, holding the hydrometer at the top of the stem. Note the approximate reading, and then push the hydrometer into the liquid a fraction of an inch beyond its equilibrium position. Don’t overdo this because excess liquid on surface of the hydrometer can also affect the reading.

When you release the hydrometer it should rise and fall steadily, and after a few oscillations settle down to a position of equilibrium. Make sure the hydrometer is not touching the side of the hydrometer jar, and you're ready to take a reading.

Read the scales at the bottom of the meniscus rather than the top of the meniscus where the surface of the liquid curves up to touch the hydrometer stem. To do this, take the reading by viewing the scale across the surface of the wort, adjusting your line of sight until it is at the same level as the liquid surface of the wort.

And don’t forget to get both the starting AND final gravity, as I sometimes do. Not all fermentations convert all the sugar to alcohol so when the fermentation has finished, you need to take a second reading to see how much sugar is left over, if any. Compare the two readings to determine the current alcohol of your beer. The most reliable readings will be before fermentation starts, and after it stops.

A hydrometer has three scales.

Specific Gravity This scale is based on the weight of water. A hydrometer floating in water it will read 1.000 Specific Gravity. A beer at 1.100 weighs ten percent more than the same volume of water. A beer at 1.090 weighs nine percent more. A beer at 0.995 weighs half a percent less. Alcohol weighs less than water, so when all the sugar is turned into alcohol you can have a Specific Gravity reading that is slightly less than water.
Potential Alcohol This scale tells the brewer how much alcohol can potentially be made from the sugars that are currently in the wort, if all of the sugars are fermentable. A single reading on the Potential Alcohol scale can NOT tell how much alcohol is already in your beer, or exactly how much can be made.
Plato/Brix/Balling This scale is used mostly by commercial breweries. The Plato scale is based on percentage of sugar that is in the liquid by weight. The scale goes from 0 to 30 on most hydrometers. If your wort reads 10 on the Plato scale, it contains 10% sugar by weight.
How accurate is you hydrometer, and how good a job are you doing at reading it? If you float you hydrometer in distilled water at 60o and Specific Gravity reads "1.000" you both both passed the test.

The potential alcohol scale can give you an idea of how much alcohol you have if you have the reading from before AND after fermentation. If it says 5% before you start and 1% at the end, then you have a 4% brew. That scale is meant for use in wines and other things that will ferment out to around 1.000. You use it at the start to see how much alcohol the wine should have when it ferments out dry.

so i screwed up is what your saying... I never took a reading before I started fermentation... just now, once it was put into my secondary.. (i had no clue) ugh!

I should have done a lot more research before starting my first batch

What kind of recipe was it? If it was all or mostly extract, then you can expect your OG to be right what it should be as long as you followed the recipe and go your volumes correct.

it was a 20 min. irish stout from midwestsupplies.. yeah it was just a basic kit not all grain or anything just extract.

You will need the beginning (OG) and end (FG) gravity readings to calculate your ABV.

Here is a handy site that does the math for you: http://www.brewheads.com/stats.php


As far as reading the hydrometer itself:
1.000 will be the gravity of plain water. The sugars increase the density of the fluid and make the hydrometer ride higher that it does in water. As the yeast eat the sugar the gravity will lower and the hydrometer will sit lower (closer to the 1.000 mark). Make sure the temperature is as close to 60deg F as possible when you take the readings. If you are drastically off you can put the correct temperature in the calculator and it will adjust for you. Take your initial reading before fermentation (OG), then take your reading after fermentation has finished. The difference in the numbers will show how much sugar was converted and let you calculate the abv. There is a formula but alot of brewers just use one of the many internet calculators available.


Example using the above website:

If your initial reading is 1.060
And your final reading is 1.010
Your beer should be about 6.7% abv


EDIT: Gah.....went to piss and found this had already been answered.

so if I get the same reading over the next couple days I should be fine to bottle... since I didnt go an og reading?

Yar....check on it in 2-3 days and if the readings are the same you should be good.

Here is a good video one of the guys on here did. Found it helpful.

http://www.youtube.com/profile?user=BobbyFromNJ#p/u/30/xtQt7HiObuU

Since it was a straight extract kit, if you followed the directions then you can just use the expected OG in the instructions as your OG. You should be within a point or so.

As for bottling... If it's at the expected FG from the instructions and stable for a few days you CAN bottle it. But if you leave it for another week or more in the primary, it'll give the yeast a chance to clean up some fermentation byproducts and give you a better beer in the end.