Dilluting My Beer In Mid-fermentation

DukeWashterbuckle said:

Hi. I recently started brewing an marzen from a kit from Northern Brewer. My OG read approximately 1.068 at the start, whereas the intended OG is supposed to be 1.058. I checked the fermenter and instead of having 5 gallons of beer in it, it has about 4.25. My SG reading right now is approximately 1.030, so it still has a ways to go. What I'm wondering is whether or not I should add more water to bring it up to the 5 gallon mark during fermentation or if I should wait until afterward. I'm mostly concerned about excessive ester production due to the gravity being so high. I'm also wondering if it would be better to add it during fermentation so the yeast eats up more of the oxygen that may be in the water. Has anyone tried this before? What were your results like?

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Travestian said:

Excess oxygen in the water will escape with the water at boiling temps. BTW, water is FULL of oxygen by nature. H2O anyone?

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LOL. Really?

And here I always thought that the oxygen atom bound to the two hydrogen atoms (at a unique 104.5* angle) to form the water molecule was a totally different critter than the oxygen molecules (O2) which can be in solution (in amounts depending on temperature, pressure, concentration, etc.).

I stand corrected.



Oh, don't try to dilute your beer while it's fermenting.

pfgonzo said:

I disagree Yoop, and agree with Travestian, though not for his H2O comment. Water from a tap or bottle or filter or whatever is going to have dissolved oxygen in it.

Adding almost a gallon of oxygenated/aerated water when fermentation already over halfway complete is going to oxidize your beer. May not result in an immediate off flavor, but it isn't something I would risk.

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