OG Always low by .02 to .05

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Mar 10, 2009
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I have now brewed two batches an Irish Stout from Midwest and a Hefeweizen from the LHBS both extract kits and my OG is always low. I know that my Hydro is calibrated at 68 per the instructions, but can you really trust that? The process I have been using is steeping grains at 155-160 for 30 minutes then boiling adding the malt all liquid for the Irish stout and liquid and DME for the Hefeweizen and then boiling for 60 minutes w/ a hop schedule. I usually also have to add 2 gallons of top off at the end which may have an effect. Any suggestion would be appreciated.

The Pol

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Feb 12, 2007
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Since you are brewing extract, your OG is probably as per the recipe. Id say that since you are topping up, it is a matter of getting the sugars evenly mixed. Relax, you are doing it properly... .02 to .05 on an extract that you are topping up, is really good. The sugars are probaby not mixed uniformly.

Test your hydro in some distilled water to check it.

Cape Brewing

DOH!!! Stupid brewing...
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May 9, 2008
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Norton, MA
The other thing you could do is just not add as much top-off water.

When making extract batches, I would always chill my wort and then take a gravity reading just to see where I was and if I was supposed to add two gallons to top up... I would add one and take another reading. I could then gauge how close I was getting to my target OG.

... and then just keep adding small amounts and mix it up really well... until you're at your target.

just make sure your hydrometer tube (or whatever you're using to take the reading in) is clean and sterile and you can then just dump the sample back in and not waste it every time you measure.