[UnequivocalBrewing]

Hello - I apologize for the long thread but I'm hoping this forum can help me out.  I've been brewing a series of New England IPAs - trying to hit similar styles to Treehouse, Trillium, Lawsons, etc.  I've done 8 of them in the last 8 months and for the most part they have been excellent.  I am using this style as a test ground to experiment with different techniques.  The last two that i've done have resulted in an astringent bitterness.  I have narrowed my potential culprits down to four things but wanted to get more eyes on this troubleshooting:

1.  Sparge water too high - I use RO water and build up from there.  I normally don't do any sparge acidification in my fly sparge and I understand this could potentially cause it.  On the flip side I haven't really changed my process and the RO water is low in alkalinity so I'm skeptical that this is it.
2.  Grain crush too granular - I have my monster mill set at .035 and maybe it's crushing too much.  Combine with #1?
3.  I have been experimenting with some Citric acid in the boil kettle to drive the PH down a bit.  I used 13 grams in a 10 gallon batch and 9 grams in a 10 gallon batch recently.  I don't know if that much Citric acid could cause some astringency?
4.  Overhopping - I doubt this is it.  The last two batches I do a very very tiny 60 minute addition of .1 oz of Columbus just to keep foaming down.  Then I did a flameout addition while whirlpooling through my dudadiesel wort chiller for 30 minutes.  After the 30 minutes I chilled it down very quickly to pitching temp.  I used: 3oz Amarillo leaf (8.9%AA), 2.5oz Galaxy pellet (14.9%AA), 1oz Cascade leaf (5.5%AA), 1oz Centennial pellet (8.3%AA).  I put these in a stainless steel hop spider and I stir the hops occasionally.  According to Beersmith this would drive 52.3 theoretical IBUs using the RAGR formula.

Here are some specifics on my process

All Grain:
65-70% 2-row (either US or MO - this doesn't matter)
15-20% white wheat malt
12% flaked oats
~3-4% Crystal type malt (carapils + honey OR golden naked oats)

Water:
RO built up with salts to hit 112 calcium, 18 magnesium, 200 sulfate, 100 chloride
I consistently hit 5.2 with 15 minutes into my mash

Mash:
Add salts to mash
1.6qts/lb
HERMS recirculation at 150F
Mashout step by increasing the HLT with HERMS to 168

Sparge:
With RO water - no acidification
Continuous fly sparge with two pumps until I hit my pre-boil volume

Boil:
60 minutes
Add sparge salts directly to beginning of boil
Add 9-11 g of citric acid directly to beginning of boil

Hopping:
As I said above
~15 oz dry hops during the tail of fermentation just as the Krausen falls (7 days)

Anyway, that's probably enough.  Looking for someone smarter than I am to help me work through this.  It's starting to get discouraging.

[natebriscoe]

What's the preboil ph?

[UnequivocalBrewing]

I've never measured the pre-boil PH.  Would you recommend doing that before or after I add the salts to the kettle?

[dilluh98]

If you are hitting pH = 5.2 in the mash, I don't see a reason for the additional citric acid in the boil. I'd look there first. Also, not sure you really need to go down to 5.2 in the mash to begin with. I stick with 5.4 for all APA and IPAs. The only thing I go down that far on is a saison. Just an opinion.

YMMV.

[HoosierBrew]

Also, not sure you really need to go down to 5.2 in the mash to begin with. I stick with 5.4 for all APA and IPAs. The only thing I go down that far on is a saison

^^  I like hop expression in American styles much better @ 5.4pH.  And saison is the only beer I mash @ 5.2 as well.  Another  $0.02  .

[natebriscoe]

I've never measured the pre-boil PH.  Would you recommend doing that before or after I add the salts to the kettle?

After salts before hops
Actually both before and after salts would be helpful

[UnequivocalBrewing]

On the citric acid:  I saw some brewing notes pasted to the walls at Bissell brothers.  It appears as if they use it Citric acid in the mash, during the end of the sparge, and in the kettle.  I also measured my finishing beer PH and it was normally about .2 higher than other New England IPAs.  I figured the Citric acid might help in driving that down a bit.  But I guess this could be other factors, primarily yeast?

On the astringency:  Thanks for the advice on the 5.4 range.  However, do we think that's causing astringency that I'm hitting 5.2?  I believe that mash PH at the higher end of the range would cause that astringency.  Or high alkalinity sparge water, correct?

[dilluh98]

On the citric acid:  I saw some brewing notes pasted to the walls at Bissell brothers.  It appears as if they use it Citric acid in the mash, during the end of the sparge, and in the kettle.  I also measured my finishing beer PH and it was normally about .2 higher than other New England IPAs.  I figured the Citric acid might help in driving that down a bit.  But I guess this could be other factors, primarily yeast?

On the astringency:  Thanks for the advice on the 5.4 range.  However, do we think that's causing astringency that I'm hitting 5.2?  I believe that mash PH at the higher end of the range would cause that astringency.  Or high alkalinity sparge water, correct?

Not sure. I know that when I brew saisons at 5.2 mash pH, I get that extra little kick of tart that I like in a saison but my saison is low on hops. Going that low with something that's heavily hopped may increase the perception of astringency. The one attempt I took at the NE APA style, I liked quite a bit and my mash pH was at 5.4 (not saying this is the only factor). It did not come across as astringent at all but it lacked a bit in the "juicy" department if such a quality is to be believed.

[natebriscoe]

In general low ph's don't cause astringency.

[kramerog]

Re sparge water, why not add the sparge salts to your sparge water rather than the boil?  This will have the effect of acidifying the sparge water addressing point #1.  I'm not convinced that points # 1 and 2 are the issue but I also don't what temp. your sparge water is at.

Like the others I think that the citric acid is excessive.

[UnequivocalBrewing]

On the salt additions to the sparge water.  I have a HERMS coil in my HLT.  For the mashout I just increase the temp of the HLT while still recirculating.  Then after my mash has hit 168 I then push that 168F water from the HLT over for a continuous fly sparge until my boil kettle hits the right pre-boil volume.  There is always some water left in the HLT.  So would I treat the HLT water for the entire volume that I put in there?  For example, I usually put about 12 gallons of water in the HLT but typically only need to push over 6-7 for the sparge.

[Stevie]

I always add my sparge salts to the kettle. I brew with RO and per Martin this practice is fine. No astringency on my end.

[dunngood]

Have you had your RO water tested? We have had some very serious problems with our store RO.

[UnequivocalBrewing]

I have not had my RO water tested.  It is a home RO system from Kinetico.  From what I understand this system is solid so I haven't worried about this. 

[natebriscoe]

I have not had my RO water tested.  It is a home RO system from Kinetico.  From what I understand this system is solid so I haven't worried about this.

That could be it. My home system varies  by the alkalinity coming in.