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Confused about hydrometer readings

Hello all, I brewed my 2nd batch ever - Irish Draught Ale about 6 weeks back and I am curious about something.

My OG was 1044 when I put it into the fermenter - so that was good, close enough to 1045. I noticed that the krausen dropped and then bubbled once a minute in a couple of days (assume that is ok). I took another hydrometer reading 9 days later and it was at 1010 - I then put it into the 2nd stage fermenter.

I let it sit there for 20 days and then was ready to bottle. I took another hydrometer reading for the heck of it and it was up to 1020. I am confused by that - is it normal for the reading to go up?

Also, I know that the kits say what your OG should be when you move it to the 1st fermenter, but what should the gravity be at the end? Is there a set value or not?

What do you do if your OG or later gravity readings are too high or too low?

Sorry about all the questions, but I am really getting addicted to the idea of homebrewing and have a feeling that I am really going to go crazy with this soon.


Well it should not go back up. That would indicate an increase in sugars so unless your yeast somehow got drunk and started working in reverse I don’t think that is the case. Not sure about your process but I’d chalk this up to user error somehow. Or your hydrometer is off. Put some tap water in your test tube and drop the hydrometer in, it should read right around 1.000.

There isn’t really a set final gravity but I say anything within 1.010-1.020 is generally good enough.

User error is very possible

Most hydrometers are pretty cheeply made. Very few I have come accross are ever right on 1.000. I have also found for whatever reason, some of the more cheeply made ones can give me varying readings even in water from use to use. Who knows.

Trust yourself more than a cheep piece of equipment. Does it look finished? Is it clear? Then it is fine. The only time you would have to worry is if it has been going strong for 2 or 3 weeks with no sign of clearing and smells like a belgian’s dirty feet. Then you have a real problem.

Was the temperature of the beer or room varying at all?

First off let me say that you should not worry about it. If it measured anywhere in the 1.010 range + 20 days it is likely to be done. Next question is was it the same hydrometer, flask and temp?

Some guy wrote this up a long time ago about hydrometers if it helps any viewtopic.php?f=13&t=8934

What about dissolved co2? After primary there is a lot of dissolved co2 in the beer. Racking to secondary may enable the co2 to come out of solution affecting the hydrometer reading.

Having never conducted any experiments on the subject, I would speculate that dissolved gasses in a liquid would lower that liquid’s density and the hydrometer would give a lower reading, although I may be wrong. Co2 comes out of solution and the hydrometer reads correctly. Though it seems to me that a 10 point difference from primary to secondary is rather extreme so I may have added exactly nothing to this conversation. :blah:


+1. Once the beer has started fermenting there is going to be CO2 in it. I always de-gas the finished beer by pouring it back and forth between two glasses before taking a reading. If you want to see the CO2 at work, just put your hydrometer into some finished beer and let it sit. You’ll see it slowly float up as the bubbles push it towards the top of the liquid, giving you higher and higher gravity readings as time passes.

In addition to degassing the beer, also check that the hydrometer is floating freely.

If you are using a narrow container (like the protective packaging that most hydrometers are shipped in) or solids are hanging on to the hydrometer, you’ll get drag that can throw off your readings.

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