Cooling Question

Would this be a problem? After I get done with my partial boil (2-3 gal), could I dump very cold top off water into the boiling water (thats in the kettle) to make 5 gal. I have an 8 gal. kettle so it will fit, and this would also help sanitize the top off water because its going into boiling water. Right?

The cooling part of this theory is fine, it's the sanitizing that wouldn't work. You would need to sanitize the cold water first. It would not get sanitized by combining it with the boiling water.

If it's bottled/spring water should it be ok?

I have done it that way for evey one of the extract brews I have ever brewed without one problem...I guess I'm either lucky or I have great water....

Yes Bottled water is ok

Yes, I've used bottled/spring water cold without sanitizing and no problems.

I've been using straight PUR filtered tap water for years to top off...no boiling...

The reason I asked this question was because I thought when the wort was hot you can mess it up by adding oxygen to it while it is hot. The bottled water is going to be full of oxygen right. Maybe iam way off

No, boiled water is depleted of oxygen.

I pour 1 gal of cold water in the primary then whatever's left after boiling (start with 1.5 gals). Then I add the rest an top off to 5.25 gals.

I used to do something similar- so I speak from experience when I say to cool the wort a bit first by sticking in in the sink in a ice/water bath. You'd think that adding 3 cold gallons to boiling wort would cool it fast, but it doesn't. It seems to get to 120-130 pretty fast, and then take forever to get cooler. This is the danger zone for bacteria. And it's harder to cool 5 gallons than 2!

So, cool the wort first, to under 100 degrees. THEN add the cold water and the boiled wort to the primary. I'd add the cold water a gallon at a time, just in case it cools it too fast, then you can add lukewarm water. Once you do this a few times, it works really well and you know what temperature your wort needs to be to be cooled to 70 degrees with the cold water.

One thing you might try is chilled/bottled spring water, thats what I used for my first batch, and it worked fine. I ended up making my wort TOO cold though.

I now do full boils with a wort chiller, I get down to pitching temp in about 7 minutes.

I get pitching temp in as little time it takes to pour top off 5.25 gals.

i cool my wort, then add water to make 5 gallons. I take water straight from the tap. always have, and have NEVER had a problem. maybe i also just get great water out here

EDIT: I get my wort to the temperature i want and pour it in the carboy. THEN, i turn my tap on and get it to the same temperature, fill up my stock pot and pour THAT in. This not only gets some stuff that the first pour missed and gets the exact temp i need, but it also allows me to pour the exact amount in because of the markings on my stock pot