[s rails]

I just realized I did not add gypsum during my mash or even during the boil for my APA.  I know gypsum helps the hop flavor pop a bit more.  I will be dry hopping this weekend.  Is it possible to boil a little water and disolve the gypsum in the boil; then add the disolved gypsum/water when I dry hop.  I guess I want to know if it makes a difference to do a water adjustment for flavor purposes post boil or post fementation?  Do I need to add the same amount as I would do preboil/mash, less or more? Will it make a difference either way?  Should I just "chalk" this one up as an error to learn from? Does anyone have experience with this problem?

[tschmidlin]

i would taste it before I mess with it.  There's no need to add it with the dry hops, you can add it later.  Dry hop it, keg it, then see how it tastes.  If you think it needs it then you can boil some and add it to the keg.

[s rails]

Thanks.  Should have thought of that.  I guess I wanted to know if it was ok to make water adjustments after the boil or fermentation.  Should be the same if the adjustment is needed.  I just need to taste it before I make the addition.

[tschmidlin]

If it is an adjustment for flavor then you can do it post fermentation.  If it was for yeast health or for mash chemistry, well, too late

[bluesman]

The main concerns with any post fermentation additions is oxidation. I would avoid it if at all possible. If the beer is that bad you may only make matters worse by trying to "fix" the issue. I recommend going with it "as is" or increasing your dry hop addition.

[s rails]

It's a recipe I've made before and won awards with.  I just never left out the gypsum.  As far as adding oxygen wouldn't that be more of a concern if I was going to store it?  The plan is to have the keg empty with in a month or two.  Once it's kegged it will be stored at 35F to 38F in my temp controlled keg freezer.

[tschmidlin]

I wouldn't worry about oxygen at all, boiling the gypsum will knock the O2 out of the water, and if you vent/open/dump/seal/pressurize it's not going to be a big deal.  Maybe Ron is more sensitive to oxidation than I am.

[bluesman]

If you follow Tom's recommendation of mitigating any exposure to air you should be fine going with a gypsum addition. It's a matter of your process control at that point. I try to avoid any post fermentation additions other than dry hopping but it's a personal choice Go for it. 

[bo]

I'd leave it alone.

[mabrungard]

Since you're dry hopping and will be opening the vessel anyhow, that will create the potential for oxygen contact.  I would add the gypsum at that time if you are sure that your starting water is already low in sulfate.  If you are just adding gypsum because some recipe said to, then it may not be a good idea.  You need to know what your water is first.

[dcbc]

I agree that you need to taste the finished product before you make a flavoring salt addition decision.

With that said, I may move through kegs more quickly or be less sensitive to oxygen exposure to the head space than some of those with more refined pallets than mine, but once it's on tap, if you think it could benefit from some gypsum, by all means, boil a half cup of water with the gypsum to sanitize, let it cool (covered), and add it to the beer.  I have done it before when I wanted to make a flavor adjustment and was very pleased with the results.  As long as you're not trying to save the beer for a special occasion in the distant future, you are unlikely to notice the effects of some oxygen exposure in the process.

Just my opinion.