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Keep Missing Original Gravity

I am only 3 months into brewing. I just brewed my 5th extract batch and every time I am low on the OG target. I have calibrated my primary several different times with different measuring equipment.

Example: target of 1.052 OG 1.042 Actual Gravity, 1.046 target 1.04 actural and so on

Hydrometer in water only has gravity of 1.006

First two batches taste good. Am I missing something? Not a hard enough boil? Inaccurate hydrometer?

Anyone have an idea? Is this something that has been asked before and I need to go back & look through old posts?

As you are relatively new to brewing, I am assuming that you are brewing exract kits. If you are brewing whole grain, then ignore the advice below.

I am new to all of this too. 2 batches brewed. 4 kits in the fridge at home (damn 15% off kits sale).

In any event, there are a number of posts discussing how OG readings are low on extract kits. Generally, the responses indicate that if you are brewing less than full boil (that is, boiling something like 2.5 gallons and adding water to primary), the OG reading is off because it is very difficutl to get the wort and water mixed well. In other words, you end up skimming water off the top when drawing a sample. I had the same issue with my first batch.

So, the general advice is, if you follow the recipie, just use the starting OG form the recipie.

They are extract kits. I shake the beer in the carboy before I take my sample so I am not skimming water.

Thanks anyway MEP

If you’re brewing extract, it’s impossible to not be hitting the target OG unless your volumes are incorrect or you aren’t thoroughly mixing the top-off water with the wort (assuming you’re doing partial boils). Or your hydrometer is off. But the kits are spot on when brewed to directions.

+1 to shadetree. you are hitting the OG that the kit predicts (if you end with the volume the kit is made for).

whats happening is: your top off water, and wort aren’t mixed 100% causing a false reading. no big deal, it is very common, and will not affect the finished product

Make sure that you are adding top-off water in slow increments and taking gravity readings until you hit the correct gravity. Everyone has differently shaped pots and therefore have slightly different evaporation rates. Don’t assume that you can just top-off to 5 gallons. You may be evaporating off a lot and will therefore end up with slightly less than 5 gallons (no big deal). Sounds like your numbers are pretty close though, and not really anything to worry so much about.

[quote=“jmarv”]They are extract kits. I shake the beer in the carboy before I take my sample so I am not skimming water.

Thanks anyway MEP[/quote]

You may think that’s enough, but I can tell you from experience that it’s not. If you use all the ingredients in the lkit and get the proper volume, there’s no way you won’t hit the intended OG.

It doesn’t really matter how much you boil off since the sugars remain. If you then top off back to the intended volume, it all comes out the same.

It doesn’t really matter how much you boil off since the sugars remain. If you then top off back to the intended volume, it all comes out the same.[/quote]

Yeah…I’m stupid. I’m just used to worrying about this with hitting OG’s in my all grain recipies.

If you’re doing a partial boil (boiling less than 5 gallons and adding water later), it can be hard to get a good original specific gravity reading. To do so, you’d really need to put the wort into the primary, add the water, mix well, then take a measurement.

The good thing is that you don’t really need to do this. You can assume that the target OG is what you are getting. Unless you have large boil-overs or spill wort, or burn the wort badly (hard to do), the project OG will be your actual OG.

Realisitcally, none of it matters. You’re not going to be so far off that the ABV of your beer is screwed up. The specific gravity when the beer has finished fermenting is much more important as it tells your beer has finished fermenting.

Volume is everything. If for example you have 4.6 or 5.6 gallons of beer instead of 5.0 gallons, then your original gravity will be off by +11% or -9% or whatever. This can make a reasonably big difference. In a recipe designed to make 5.0 gallons at 1.050, you could be anywhere from 1.045 to 1.054 in the examples provided here. If you care about hitting the original gravity perfectly, then it is vital that you hit the recipe’s volume very accurately. Personally, I wouldn’t fret too much about 4 or 5 points. Sometimes it matters, but usually it doesn’t. But when you’re regularly off by like 10 points, then accuracy of volume measurements, and your hydrometer, are some things to be a little more concerned about. It’s almost for certain one or both of those two things.

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