OG Question

[Dave1096]

So, a friend and I brewed a 10 gallon batch together and split the batch into our own carboys. We got distracted while brewing and forgot to take a pre-boil gravity reading, so we have no idea what our efficiency is. My friend took his OG and got 1.064 which is lower than our targeted 1.070, but he later realized that he forgot to flush the water out of his hose before he started filling his carboy and ended up with probably 1/2" of water before his wort started to fill his carboy. Since my carboy was filled last I didn't end up the same dilution issue. I forgot my hydrometer at his house, so I didn't take my own OG and went off of what his reading was and just pitched my yeast.

I know there is no real way to know, but does anybody have an opinion of how much a 1/2" of water in a 6.5 gal carboy might drop the OG of a 5 gallon batch? Just trying to guess whether our efficiency was off by as much as we think or if his reading was low because of the added water. Thanks.

 

[Hammy71]

Your probably pretty close to the 1.070. I know with my system, a regular bottle of spring water lowers my OG by 2 points on a 5 gallon batch. So, I'd guess a 1/2" of water is going to give you the 6 points. Gotta ask though.... Why the hell do you have water sitting in your hose you use to drain your kettle? I'd be more worried about contamination in your pals beer.

 

[Dave1096]

It was leftover top up water in the line attached to his pump. He moved the line and used the same hose to drain the kettle...but obviously forgot to purge the water from the line first.