First All Grain BIAB: Fail! Anyone care to walk through my process with me?

Hi all,

I've been lurking this site for a while now, love it, and finally have a good reason to introduce myself: I seriously f-ed up my last batch, an all-grain farmhouse ale using the BIAB method. I have a few possible culprits, and possibly more than one point of failure, but the end result was a nearly undrinkable beer with slight cooked corn odor and a (non-hop) bitter astringency to the finish that I really can't place. Swishing the beer across the tongue actually makes it go slightly numb, with an oily, heavily-coated feel to it. This was only our 8th batch ever, the first all grain, and we're ready to get back on the horse but would like to understand where things went wrong.

Here is the recipe:

Grain Bill:
6.75 lbs Pale Ale
2.75 lbs Wheat
2.75 lbs Vienna
1 lb Crystal 40L
NOTE: we had milled the grain but a scheduling conflict delayed the brew 3 weeks. I kept the airtight bag in the refrigerator the entire time, but could oxidation of the grain contribute to a "dull" finished beer flavor?

Hop Schedule:
1 oz Tettnager 60 min
0.5 oz Styrian Goldings 5min
0.5 oz cracked coriander, 10 min

Yeast: Wyeast Lim Ed. Farmhouse Ale 3726, 1 L starter (with stirplate)

Other additions:
1 tbsp gypsum in strike water (using city tap water, never had issues before)
10 drops fermcap @ start of boil
Brewvint yeast fuel @ 10 min
Whirlfloc, 1 tablet @ 10 min

Mash Schedule:
5 gal strike water, 156F, 60 minutes (temp held within 2 degrees)
Sparged with 3 gal @ 160F
Collected 6.5 gal with runoff gravity of 1.052

We had a good, vigorous boil (no lid) and our post-boil OG was 1.063 and just under 5 Gal. We chilled to 80F quickly with an immersion chiller, transferred to the carboy, aerated via shaking for 10 minutes, and pitched the yeast starter, which was decanted to about 0.2L of just the yeast cake and minimal wort. Fermentation kicked off within 8 hours and was aggressive the first day (heavy krausen) but slowed after 24 hours. We realized at that point that our fermentation chamber was too cold (76F) and cranked it to 85F for the rest of the primary. We had good bubbling in the blow-off but no longer any significant krausen formation. We decided to let 'er go and 3 weeks later we hit our target FG of 1.012 and tasted the result: spicy, full flavored, and no signs of problems. We let it sit one more week on the trub, then cold-crashed and bottled.

Here's where I'm fairly sure we screwed the pooch: we always use a 3/4" blow-off tube, which dumps into a bottle of star-san solution, as our air lock. We have never had an issue before this batch, but due to the high fermentation temp vs. 50F cold-crash temp, we ended up siphoning 2-3 cups of star-san solution back into the carboy due to the change in temperature. ACK! I can't tell whether it's just the flavor of the star-san (we did NOT taste the beer at bottling... a mistake, obviously) or an infection (assuming one could grow in the blow-off liquid despite the star-san) that is making the beer taste so foul. The tongue-numbing action and slippery coating are not unlike the feeling you get from straight star-san when it gets on your hands.

If the finished product just tasted like ass (due to star-san contamination) I'd be fine, but the slight cooked-corn smell, blandness, and almost acid-tasting astringency on the finish makes me think that more than one factor is at play here.
- DMS? The beer has only bottle conditioned for about 20 days, so I'm wondering if any of this could clarify/improve with time.
- Stale grain? I can almost taste the "good beer" behind the off-flavors and the beer tasted good prior to the star-san disaster.
- Fermentation temperature? Everything I read said that this yeast loves the higher temperature range.
- Infection? I really don't know what a bacterial contamination tastes like (other than brett or pedio).

I'd love to hear some opinions from y'all!

A million thanks for your time,
Ryan

Have you used this yeast before,2-3 cups of sanitizer does not sound tastey. Get ph papers for your mash keep it between 5.1-5.5 mash temps.I adjust mine with Baking soda to raise it or cl2/gypsum to lower if its not in range.Although i generally would like to stay away from using salts and just find a good spring water.

eek. You sound like you know what your doing. Don't take my suggestions as insult to you knowledge, its just from personal experience...what little I have.

bitter astringency: Every time I hear that I think of my first few all grain BIAB. My culprit was high ph water from the tap that probably extracted tannins. My brews are much better now with blended reverse osmosis water. Do you know your water report or do you check mash PH? the high ph doesn't matter so much with extract but will ruin an AG batch for sure.

Not familiar with the yeast or farmhouse but 85 degrees is warm.

As far as star san, I wouldn't be too worried about it. If I remember right once the ph drops when mixed with beer it basically becomes yeast nutrient. But maybe, two cups does sound like a lot.

good luck

The acid is Star-San will probably get you the bitter flavor, and the surficant (the stuff that makes it bubbly) will give you the slippery mouthfeel.

I suspect that the pH change probably throws the pallet of the beer way off, that combined with the surficant coating your tongue accounts for blandness and bitterness; also some of the off flavors. I have a funny feeling that the Star-San contaminants might have brought some of the imperfections to the forefront with the pH change.

I doubt the stale grain did it, 3 weeks in the fridge for crushed grain certainly isn't ideal, but it shouldn't be anything that would cause what you are talking about.

The numb tongue is about the only thing that might be an honest to goodness imperfection, that can be caused by yeast, particularly when stressed at high temps.

I agree that it sounds like you know what you're doing and you may have several issues that are causing some problems.

Cooked corn smell makes me think DMS. Examine your process and ensure you are boiling vigorously enough and long enough (without the lid).

Get your city water tested (Ward Labs) or try using bottled spring water or RO water.

The star-san suckback shouldn't hurt you too much but it's best to prevent this from happening again in the future because you never know.

The oily mouth feel makes me think possible infection but that's just a guess.