Adding water to wort, and keeping sterilizer for future use

Did a 1 gallon kit - just bottled it last week. When I moved the wort from the pot into the carboy, the level was a couple inches under the “one gallon” lettering on the carboy. I asked on the product page whether I should have added water at some point, and got this reply:

“Yes. You’ll want to add water so that you have 1 gallon of wort inside your fermentor. Water straight from the tap will work for this purpose (you don’t need to boil it).”

But isn’t there a contamination risk by doing that? Really seems like I should boil the water, maybe add it while it’s boiling.

Second question: can I save the sterilization mixture for future use? I’m going to try testing the gravity with my next couple of batches, so I’ll have to sterilize whatever I use to withdraw the wort/beer, and wonder if I have to make new every time.

It is safe to use tap water from the faucet to top off if you have your own private well. Any municipal water will be treated with chlorine or chloramines. This treated water can cause a bandaid like off flavor in your beer. The water can be treated with Campden tablets, but for small batches it would be handier to keep bottled water or distilled water on hand for this purpose. This water would not need to be boiled either.

If your sanitizer is Star San solution it can be saved and reused as long as dirt and other crud isn’t introduced and the pH is below 3.2. I keep my Star San solution in one gallon jugs and a spray bottle for sanitizing small parts and beer/wine thief for SG samples.

In addition to @flars recommendation to use bottled water, put that gallon of water in the freezer about 20 mins to chill it before adding. It will assist with cooling the wort.

Ahhh one gallon batches… Taking a reading is such a waste! What I would seriously consider is sanitizing the hydrometer and placing it right in the 1gal carboy. BE FOCUSED ON YOUR SANITATION AND THIS WON’T BE AN ISSUE.

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One thing I’ll point out out about not needing to boil top-off water.

The yeast we pitch is alive and therefore gives your wort an immune system; a Wyeast smack-pach has upto a 100 billion cells. So most bugs just can’t compete. In comparison, nasty tap water may have a few hundred bugs in it, Yes, there are bugs that can compete with yeast, like lactobacillus, but for the most part tap-water bugs are a non-issue.

Think of the bacteria in untreated leap-water like bear. Really bad news in the unpopulated (unpitched) boonies. If you see one, you better move cautiously in the other direction; known bear habitats are not great places for pitching a tent. Once you pitch yeast in your wort though, the microscopic lasdscape is like downtown Manhattan, only more so. What chance does a bear havet there? Even a hundred bear? Snowball’s chance in hell really. Sure, a bunch of people may die before the bear infestation is resolved. But I can assure you, Manhattan is not worried about bear attacks.


I hate to be a stickler for detail here, but products like StarSan are sanitizers, not sterilizers. Sterilizers kill everything. Sanitizers reduce the bacteria, mold, etc. counts down to a level that will rarely cause infection. To use the bear analogy (which I really like, BTW), you’re killing off a bunch of bears so that the people vastly outnumber them, but you haven’t kill off all the bears.

Thank goodness its winter up here,NO BEARS !! :joy: Sneezles61

Okay, so: I don’t have to worry about any bears that might sneak through my faucet if I add water. Good to know. And it sounds like you all are at least not opposed to the idea of topping off? I worry about diluting the taste, but I just got started so I don’t know.

And the sanitizer - not sterilizer - if I sanitize my stuff and then keep the liquid in a piece of tupperware for the next time I need it, is that going to work?

Is your sanitizer Star San? I keep my Star San solution in one gallon vinegar jugs. The vinegar jugs are thicker plastic than distilled or spring water jugs. Vinegar is also an acid so I thought it would be appropriate for an acid solution of Star San.

Tupperware will hold acid food so it may be okay for the lower pH sanitizer. The one gallon jugs are easy to handle and reseal though.

Topping off is an good thing to do.

I wrote the following in the context of a one gallon recipe as @LB brewed a 1 gallon kit.
For a one gallon recipe, the amount of malt/hops/… is measured assuming a gallon of wort in the fermenter. There will be some loss of water during the boil, so many recipes will start the boil with 1.25 gallons - anticipating that a typical 45 minute boil will boil off a quart of water. If more than a quart of water is lost during the boil, topping off to one gallon is a good thing to do.

When I ferment in a one gallon carboy, I top off in the kettle just before starting to cool the wort. I use my stirring paddle to measure to the one gallon level.

@loopie_beer’s ideas on topping off with chilled water and hydrometer in the carboy are worth exploring.

Yeah, Tupperware works fine. I keep my Star San solution in a large bowl, mainly because my wife has sold Tupperware for 15 years. :grinning:

I use bleach bottles and laundry soap bottles… No problems… Yes I do check my pH before I use it…Sneezles61

Hey sneezles61.
Polar bears?

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A vinegar jug sounds like a good idea. You don’t worry about the taste from the residue?

There’s no residual vinegar flavor. The jugs rinse a lot easier than a bleach solution. Having no residual aromas may be due to the quality of the plastic.

I haven’t seen one…. yet!! :open_mouth:Sneezles61