Hi All,
I’m very new to brewing beer and have just put batch 2 into the fermenter Sunday. So far, I’ve forgotten to do a SG measurement on both batches.
My question is, is there any reason other than curiosity, to take a measurement now?
Also, can I take a measurement and get a “good” number after bottling?
I just put a bottle of batch number one into the fridge this morning to have a taste after work. Its too young but I too anxious to wait another week to have a taste test!
If you don’t think it’s done, don’t waste the beer to take a reading. If you’re brewing extract beers and you end with 5gallons then your OG will be what’s on the recipe.
You could test the gravity of the bottled beer but you will want to be sure all the carbonation is out of it first. I was thinking that because you add sugar that the gravity might increase but since sugar ferments completely, the SG reading should stay the same.
It’s recommended but obviously not required to take gravity measurements when pitching the yeast, and when fermentation seems to be done. I further recommend that after you think fermentation is done, then before bottling, wait another 2 or 3 days, and take a second reading. That way you can confirm that the final gravity is constant and there is no further fermentation occurring. If the gravity is still changing, then you could have bottle bombs.
Measuring the gravity of the bottled beer will help you determine the actual alcohol level, but I don’t think it will work if the beer is carbonated as the CO2 bubbles would tend to increase the gravity reading. So if you pop open a beer and leave some out for 24-48 hours at room temperature until it is totally flat and then take a reading, this would be more accurate.
Piggybacking here…
I’ve also never taken a gravity reading. I brew extract, so never cared that much. But I’m planning on trying an all grain or partial mash soon, so I ordered a hydrometer… somewhere, I saw someone recommend saving the post-fermentation sample in a plastic bottle and do the after-a-few-days second reading with that sample. Less beer spent on samples, less chance for infection by getting beer out of the fermenter, etc. The thought is that the sample will have yeast in suspension, too, so any further fermentation would happen at the same rate as your fermenter. Sounds fishy to me… anyone else heard of this?
If you’re concerned about the loss of beer (or wort) from hydrometer samples, get a refractometer which only requires a drop or two for a reading. Or don’t worry about the few ounces used in the hydrometer. 
[quote=“uberculture”]Piggybacking here…
I’ve also never taken a gravity reading. I brew extract, so never cared that much. But I’m planning on trying an all grain or partial mash soon, so I ordered a hydrometer… somewhere, I saw someone recommend saving the post-fermentation sample in a plastic bottle and do the after-a-few-days second reading with that sample. Less beer spent on samples, less chance for infection by getting beer out of the fermenter, etc. The thought is that the sample will have yeast in suspension, too, so any further fermentation would happen at the same rate as your fermenter. Sounds fishy to me… anyone else heard of this?[/quote]
I’ve heard of it, but never practiced it. For me there’s too much variability; pitch rate (unless you take the sample post-pitch), geometry of the vessels, etc. But then again, I’m sure these variables are too small to matter, so in the end it’s more a preference thing for me.
Thanks All!
Good info. I think I’ll just take a read and see what I get and also learn how to use the hydrometer in the process.
Have not cracked the 1st batch yet either. My boy got sick over this past weekend, and now the wife looks like she’s got the flu. Up all night with the nasties!
Poor girl, yesterday was her birthday too…not the best present in the world! Cheers!
