Gravity and water questions

I have found that my gravity readings on both ends-OG and FG, by 10 points.
I'm fairly new to brewing so I figured I was just making beginner mistakes.
I took a reading of my tap water and found it reads .990 instead of the expected 1.000.

Can I bring my water up to 1.000 with additions, or should I just start brewing with RO water or something like that? I'm brewing mostly extract kits with specialty grains, so I wouldn't want to over do an addition that my already be in the extract.

thanks for your advice.

What temperature is the water when you take our reading? I think most hydrometers are calibrated to 60F so for starters you might want to try a sample at that temperature to see what it says.

d_jabsd said:

I have found that my gravity readings on both ends-OG and FG, by 10 points.
I'm fairly new to brewing so I figured I was just making beginner mistakes.
I took a reading of my tap water and found it reads .990 instead of the expected 1.000.

Can I bring my water up to 1.000 with additions, or should I just start brewing with RO water or something like that? I'm brewing mostly extract kits with specialty grains, so I wouldn't want to over do an addition that my already be in the extract.

thanks for your advice.

Click to expand...

I would assume your hydrometer is off, not the water. Just add .01 to all your readings.

The water was straight out of the tap around 66-68 degrees. my OG wort measurements were taken slightly warmer, around 78, and then fed into Brewpal to compensate for temp. the FG measurements were taken with the wort at room temp- 68-70 and fed into Brewpal.

The warmer your water, the lower your gravity will ready, so if your took readings close to 70, then that would show your hydrometer to read lower. Get some water to exactly 60, and then drop the hydrometer in it to test it, but it should be fine.

Hydrometer correction on a 70 or even 80F reading will only be a couple gravity points, not 10. Sounds like your hydrometer is messed up to me. Do you have a brewing buddy with a hydrometer that you could borrow to test against your water just to confirm? Worst case, just buy another one. They're only a few bucks. If a second hydrometer confirms these readings I think you need someone smarter than me to help you figure out what's going on.