Hydrometer off

[guitarsophist]

I am on my third batch, doing extract brewing with kits. Each time, my initial gravity was high. On all three kits the predicted initial reading was 1.045. On the first I got 1.058, on the second, 1.070, and on the third, 1.060. I discovered that the 5 gallon mark on my bucket was actually 4.5 gallons, so that probably explains part of it. I need to put in more top off water. However, today I put my hydrometer in a beaker of tap water at 70 degrees, and it reads 1.006. The chart says that I should add .001 to that to compensate for the temperature. So that is maybe 1.007.

My question: Tap water is not pure, but it seems like it should be closer than that. Is the hydrometer off? Should I use it and subtract .006 from whatever reading I get, or should I get a new hydrometer?

Thanks,

John

 

[Reelale]

Yes, your tap water will not be that far off from distilled or sterile water. Just use your correction factor, or buy a new hydrometer.

 

[copper]

I found my triple scale float reading off by .002 on my tap water, but that could be an effect of the water. A margin like that is easy enough to compensate for so long as I don't forget about it, and is within what I would consider a reasonable tolerance for a non-precision instrument. .006 sounds like quite a lot to me. I would probably try to go with it but I know that I would get fed up with the additional compensation after a while and buy a new one.

 

[guitarsophist]

Thanks guys. That is pretty much what I thought. This brewing stuff is not really so complicated but it sure is fun!

John

 

[instapman]

I droped my hydrometer 3 batches ago. I am looking for a refractometer....Snells law anyone???

 

[guitarsophist]

What is "Snell's Law"? Is it anything like Gear Acquisition Syndrome?

John

 

[instapman]

What is "Snell's Law"? Is it anything like Gear Acquisition Syndrome?

John

A quote from Wikipedia;

"A formula used to describe the relationship between the angles of incidence and refraction, when referring to light or other waves passing through a boundary between two different isotropic media, such as water and glass."

I had to look it up too...I like to know about the things I use (or want to use) for brewing or anything else....dont ask me to explain it...I trust Snell

 

[guitarsophist]

Ah, that is different then. A scientific principle. Gear Acquisition Syndrome (GAS) is the belief that if you only had that one new piece of equipment (a guitar, a preamp, a wort chiller, a kegerator, etc.) you would be a star, and all would be good. Happiness, success, and victory are one purchase away. Wives usually see through this pretty quickly.

John

 

[instapman]

Ha!