Hydrometer - When/How and Why?

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BeerNoob

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Ok so, I'm not afraid to admit it, I'm bad at making beer. I seem to find a way to screw it up every time I make it. However, this does not stop me from continuing my quest for a drinkable brew!

Unfortunately, this post is not a FAQ or even an instructional, which I would someday love to write, I really just want to know when, how and why I am supposed to use my hydrometer.

I have done a lot of reading since I started brewing and haven't found any concise explanation for it that draws everything out plainly. So please, anyone that has a web page, a thread, an explanation or some other link of why this ultra-important device is so, well... important, I would be greatly thankful.

Here's what I know:

1. I own a hydrometer which came with my brewing "kit" i bought locally.
2. The hydrometer measures the "gravity" of a liquid.
3. The beer recipes that i use often have a number like "O.G. 1.045".
4. I'm supposed to use it at certain intervals.

Other than these things, I have no idea why I'm using this hydrometer or how these readings are supposed to influence the various steps one would take in brewing beer. Perhaps the coveted hydrometer is the answer to all my problems?

HELP!
 
A hydrometer will help you with a couple of things. When you've got your wort all done after brewing, it will tell you that you hit your numbers. If you're brewing extract, you will usually come close. It comes down to volume at that point more than anything.

When your beer is done fermenting, it will tell you if you hit your expected final gravity. If you expect something like 1.012, and you are at 1.018 or so, you might still have a ways to go. Your yeast might have also given out on you, so that's something that happens and you want to be able to know where you are done fermenting. If you take readings a couple of days in a row and your numbers are stable, you're probably done fermenting.

If you have an OG reading and a FG reading, you can calculate the amount of alcohol in your beer.

Some people don't use hydrometers. I have readings for all of the beers I've ever brewed. I like knowing everything went well.
 
Ok so..

O.G. means Original gravity which means what the gravity of my wort "should be" before any fermenting takes place?

F.G. Which i assume means Final Gravity? Which I assume would be the gravity of my wort(which is now considered to be beer) after fermentation is completed?

I should be taking these readings how often? At the beginning I get and at which point would I want to do it again? I imagine taking a lot of readings will increase the chances of an infection since my primary doesn't have a valve at the bottom.

Also, what reading am i looking for? Am I supposed to wait until activity slows and then give it another day or two and take readings to see if it's changed much? In which case, if it has changed, let it go longer, if it hasn't changed it's ready to bottle or would it be ready to rack into the secondary?

Lastly - if there are people that don't use hydrometers but instead use their elite beer-making instinct. How do they know when to rack or when to bottle?

I fear that most of my batches have been failures because I didn't know exactly when to rack or bottle so in some cases, I racked early and took the unfinished fermenting wort away from the yeast and other I racked too late and my yeast had died and soured my beer.

My first batch that I ever made when I knew absolutely nothing was by far my best. I'm afraid at at the point now where I know enough about brewing to screw up my batches and not enough to make them good again.
 
Yes, you have OG and FG right.

You take one at the beginning. I don't even bother touching my beer for 14+ days after that. I'd take one on day 15 and 16, and if you're steady you're probably ok. Yes, you can increase chance of infection, but if you're properly sanitizing your thief, you should be ok to bottle. I don't use a secondary, but some people do.

Visual activity is an indicator, but not the end all of when fermentation is slowing or stopped. Most people who don't use hydrometers are experienced enough to think they know what happens every time or lazy enough to not bother because things are "good enough." I want to know everything that happens with my beer.

Don't worry about yeast death. If you're getting soured beer, you likely have a sanitation issue. The only really off flavor in this concern would be diacetyl from racking too early. Yeast death is like a 9-12 month issue, not a 3 week issue.

Step back, think about every step you go through. Maybe even write out your process in a different post and see if people can walk you through what your mistakes might be. I would guess you don't control temps well enough and you don't pitch enough yeast. And you might have something that is infected. I REALLY don't think this is a point of failure for you.
 
Ok, I appreciate the responses :)

So let's take my current situation - I'm brewing a fairly basic, extract IPA. I started on Thursday afternoon(3 days ago)and I didn't take a hydrometer reading. Let's assume that because it's an extract only beer that my hydrometer reading was where it was supposed to be which is 1.065.

I used Nottingham yeast which took nearly 30 hours before any activity showed but once it started my primary lid almost popped off because it was fermenting so quickly(constant bubbling in the airlock) and some krausen(sp?)(foam?) had clogged the airlock hole. Airlock activity has since slowed to a bubble about every 5 seconds so I guess it's still fermenting a little. A friend of mine who has some brewing experience told me that he usually would rack to his secondary when the airlock slowed to 4-5 second delays and let it finish there.

Again, I don't have an instinct for when I should rack to my secondary. If I were using my hydrometer like a good little brewer, would I wait until airlock activity had all but stopped to begin taking readings or would now be a good time because it has activity has slowed significantly? Does this matter or is it simply preference?

Do I want fermenting to be complete before I rack to my secondary? Why or why not?

If I'm not adding any flavouring such as fruit or dry hops, should I not waste time with a secondary?

I also understand that every beer is different and there are a lot of factors that go into brewing such as ambient temp, type of beer, type of yeast, brewer preference, etc. so there's no single answer for a question like that but I'm trying to develop a feel for this sort of thing and frankly, I trust you guys more than I trust myself right now.
 
I suggest that you read "how to brew" by John Palmer. I am probibly one of those lazy brewers, but I never take a reading exect when I start and when I bottle. i usually wait untill bubbling has all but stopped before I rack to a secondary and then wait at least 2 weeks (or until my work schedule permits) to bottle. I like to rack because I have found (at least in my limited experance) that it tends to produce a clearer beer without as many off flavors. (I am also a newb with only about 9 batches under my belt) best of luck and remeber RDWHAB.
 
I take gravity reading at many different points during my brew day. I also drink/taste everything at each step. I like seeing how things have changed from each process the wort/beer goes through(this includes eating a hop cone once THAT was an experience). I take copious notes too. I'm not winning awards yet, but I think that my beers are tasting better than they did a year and a half ago, other have told me this too.

Try to brew the same beer several times changing one thing at a time, see how different techniques affect your beer. In time you'll learn to trust yourself when you see what works and what fail given you set up.



Secondaries are not necessary. I've done both and in the end I still ended up with beer.
 
If you visualize the mechanics of what the hydrometer is doing it makes more sense. I am assuming you are brewing either extract, or partial mashes. When you add your cooled wort to the 3-3.5 gallons of water in your primary fermenter and stir, this is where you would take a sample and aquire your O.G. sometimes listed as S.G. ....Now this is where the visualization process helps...your wort is almost "candy like". It is thick, dense, and sweet. So, when you drop your hyrdometer into your sample it tends to "float" higher. The same princpal goes for floating in the ocean. The higher the salt content in the ocean the easier it is to float on your back...Over time the yeast will convert the sugars to alcohol making your now beer far less dense, allowing the hydrometer to drop in the sample, like floating in fresh water compared to salt water.
 
So just to update. I started a new brew today and I actually measured the O.G.! it came up as 1.055 which is a fair bit higher than the recipe said it should be although I made a few changes so I wasn't that surprised.

So I know now that once fermentation appears to have slowed or stopped I should take gravity readings to verify for sure.

I just have 1 or 2 more questions related to this subject:

1. Is it possible to estimate the outcome of the ABV based on the O.G. and the recipe?

2. If you add fermentable sugars, such as honey, to your boil, will that make the O.G. and F.G. changes more drastic? Such as... is it unheard of for a beer to go from say, 1.06 to 1.01?

3. is it possible for there to be too much alcohol in a beer as a result of the recipe? And if you can have too much, what happens when it gets to that point? Will it ruin the beer?

Sorry for all the weird questions, I just love the science of it all and I feel that when I know how and why something works a certain way it improves my results.

Thanks!
 
1 yes. I'm not that great with the math side of brewing, but each yeast company states the degree of attenuation their yeast is capable of. figure out that persentage, that is your expected final gravity. then OG-SG * 131. I doubt you'll be spot on, so rely on the hydrometer, there are many variables that effect this

2. Adding more fermentable to get a lower finaly gravity from your wort? Problably not, though I never tried. The Reason that your beer dosen't reach .999 FG like wine is that some of the surgars, dextrines for example, are turned into food for the yeast.

3 Depends, yeast will make alcohol up to their tolerance, and then sometimes even a little passed, but they become stressed and produce off flavors. Now if you have a very attenuative yeast, with high tolerance, in a very fermentable wort, you could end up with a lot of alcohol. Harsh alcohol flavors is never a desireable flavor profile. Now if you have brewed a big beer with high alcohol, you can age, (like a barley wine) and hopefully your brew will mellow
 
yup, yeast have to sit in their own waste, so they only have a tolerance for so much. Different yeast strains can get you different levels of alcohol - they also impart their own characteristics.

Sounds like you've got the hydrometer thing down - now that you've made a new batch, let it sit and ferment for 2 weeks (actual fermentation time is less, but it's conditioning and cleaning up after itself). Then you can move to a secondary for another 2 weeks. Or, you can skip the secondary completely and let it sit for about 4 weeks.

Your original post indicated you were making "bad beer" -
so, something else to pay attention to, in addition to the Sanitation issue mentioned above, is Temperature Control -

At what temperature are you pitching the yeast? at what temperature are you keeping your fermenter?

you will find immensely better beer occurs when you keep your wort to the low end of the temperature preference for the yeast strain you are using. (yeast specifications are available on the manufacturer's websites).

Good luck - you CAN make good beer!
 
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