[gleece]

When I brew an extract batch, I use water from my fridge filter and boil ~3 gallons. After I've cooled my wort, I usually top off to the 5 gallon mark with purified drinking water from the store. Should I be using a different water, like distilled?

[brewinhard]

If you are brewing strictly extract then you can and should use just straight distilled water.  When the malt extract was produced it was created with all the necessary minerals in the wort that the maltster desired, which means you already have the minerals needed in your wort from the extract.  Adding extra spring water will add additional minerals that may or may not be good for your beer style of which you really have no way of knowing the water profile of that spring water. 

You will also produce a better beer (with more accurate hop utilization and better color esp. in lighter beers) if you can do a full boil (i.e. start with 6.5 gallons and boil down to 5.5 gallons over one hour).

If not, then brew with distilled in your kettle and top up with distilled after the boil.

[Stevie]

One thing to note is bottled water should be sanitary enough to add straight to the chilled wort

[brewinhard]

One thing to note is bottled water should be sanitary enough to add straight to the chilled wort

+1.  Chill that down super cold, and you have an extra way to bring down your wort temps after boiling.

[santoch]

I respectfully disagree with the philosophy that only distilled water should be used in extract batches, for the very same reason BrewinHard gave about using Spring Water.

The reason I think this is that the extract producers are producing a general purpose product for use in a wide variety of beers.  They could not possibly know whether you will use this extract in a pilsner, an IPA, a sour, or any other style.  We will not know exactly what the mineral profile was when they made it, but I seriously doubt that it was the right mineral profile for that Dortmunder Export, or that IPA, or that Schwarzbier, or that Berliner Weiss, or that RIS, that you've been itching to brew.

Putting myself into the head of the maltsters, what I would expect is that there was just enough mineral for them to convert the grains, and that's about it.  By aiming low, they can "get out of the way" and give you a product that will tend to produce a "layup 5-iron shot down the fairway" decent beer every time, but you'll probably never be able to "hit the green for an eagle" right out of the box.  Another thought is that at worst, they don't even take our mineral contributions into consideration; they just use their local water plussed up with just enough phosporic acid, calcium chloride and/or gypsum to get it to convert.  Then who knows what style that would match?

My suggestion to the OP is to top up with water treated to be closer to the target water profile of the style you are shooting for, but back off a third or so to account for some unknown level of mineral content you get from your extract.  Unfortunately, there is simply no way to get any closer. The best thing we can do is try it, and tweak it until you dial it in exactly how you want it to taste.

FWIW, I know that back in my extract days, my beers improved a lot once I began adding minerals to my water.   I live in western WA state at the foothills of the Cascade Mts.  My water profile is very close to Plzen, or just a touch above distilled.  The difference was very noticeable, and it rang true for most styles.  I just looked at the water profile target, figured out what I needed to add to hit that profile (using Promash), backed it off a little, and went with that.  If it didn't taste right, I kept trying till it fit, but that was pretty rare.  The amounts of minerals we are talking here are small and any quantity errors tended to fall below my perception threshold.

Most homebrewers progress from Extract to AG because of issues like this.  We steep specialty grains rather than use amber or dark extract (What exactly is in that stuff?  Roast barley? Black patent? Chocolate?  All 3? What ratios? Who knows?)

You absolutely will be able to brew good beer with extract.  You absolutely will not know exactly what's in it.  All you can do is make an educated guess, and keep tweaking until you zero in on your target.  Which lasts until they reformulate it, or your LHBS gets a different shipment or changes suppliers or something like that, at which point you start over.

[mabrungard]

Agreed! Topping off with nothing but pure distilled or RO water could leave the beer bland(er). Appropriate salts should be included in the top-off water to move the profile in the general direction appropriate for the beer being brewed. The most important factor is this: DON'T TOP-OFF WITH WATER THAT HAS MUCH ALKALINITY. That is almost certain to degrade your beer. Both RO and distilled water have little alkalinity and they are safer bets if you don't know how much alkalinity your tap (or that jug of spring water) has.

[brewinhard]

The most important factor is this: DON'T TOP-OFF WITH WATER THAT HAS MUCH ALKALINITY. That is almost certain to degrade your beer. Both RO and distilled water have little alkalinity and they are safer bets if you don't know how much alkalinity your tap (or that jug of spring water) has.

This is what I was referring to. For a newer brewer, adjusting water is just not something most immediately look into.  It is typically one of the last things that a brewer will study to make their beers better.  Until that point, it probably is wiser to top off with either RO/ or distilled water for ease of brew day.

[Steve Ruch]

One thing to note is bottled water should be sanitary enough to add straight to the chilled wort

+1.  Chill that down super cold, and you have an extra way to bring down your wort temps after boiling.

Absolutely.

[leprecaunjon]

to be quite honest there is a book dedicated to brewing water, with that said i have yet to read it LOL all i know is the city water makes my beer undrinkable here in fairfax VA. I started brewing off of a well in a small town not far from where i am now, the texture of the water and flavor sold me and i have only used well water from that area ever since. a few days before each brew day i drive out to my grandmothers and pick up a few gallons of "grandmas brew'n water".

[emcfarden]

BTW you can look up the mineral content of bottled spring/drinking water online. So if you have a couple of unopened jugs in the kitchen don't feel like you have to abandon boil just to run up to the store and get distilled. As long as you're confident its sanitary then go for it.     

[euge]

My understanding is that "extracts" tend to have a high sodium content due to the use of softened water in the mash which is then concentrated.

It's better to top or extract brew with R/O or even better a spring water like Ozarka. Spring water usually has a beer-complementary mineral profile.

[dmtaylor]

at worst, they don't even take our mineral contributions into consideration; they just use their local water plussed up with just enough phosporic acid, calcium chloride and/or gypsum to get it to convert.  Then who knows what style that would match?

I believe the statement above is most likely the truth.  If I was producing malt extract on a massive scale, I'd be using whatever water was available locally, plus the cheapest of pH control, whichever chemical that is (I'm not sure which -- gypsum? phosphoric?).  To figure that they'd do anything different with salt additions or softeners in an attempt to emulate the most likely style that their extract would be used for, or even a middle of the road average, is... extremely unlikely.

I shall continue to advocate always the use of distilled water for most extract brewing, just as brewinhard stated originally.  The only exceptions are where you might be brewing a style known for its hard water or firm bitterness (IPA, anyone?).  Other than that, stick with distilled and let the extract give you a somewhat ordinary level of minerals automatically.  Because you really probably don't want to know what crap water they used to make the extract, much less add more minerals on top of it!

My humble opinions.  Cheers.

[mabrungard]

My understanding is that "extracts" tend to have a high sodium content due to the use of softened water in the mash which is then concentrated.

NO! It is only Briess extracts that have high sodium content. As far as I have found, all other extract manufacturers use low sodium brewing water and have low sodium content extract.