troubleshooting astringency in low ABV beer

[mwill07]

I recently brewed an ordinary bitter and entered it in a club competition. I took 2nd place, both judges rated it as a 32. One common note from both judges was astringency, which I can definitely taste. I'm trying to understand where it comes from.

General recipe:
Marris Otter: 6 lbs
Special Roast: .25 lbs
Crystal 80: .5 lb
Mashed at 158F, 1 hr.
pre-boil gravity: 1.035

Magnum: 0.6 oz, 60 min
Williamette: 0.5 oz, 10 min
williamette: 0.5 oz, 0 min


BIAB: I did not squeeze the bag at all...drip drain only.

7 gallons of mash water
water profile (ppm):
Ca: 55
Mg: 8
Na: 10
SO4: 95
Cl: 48

Measured mash PH: 5.27 (give or take 0.05, measured at 20 min, 40 min, 60 min)

My rig is an eBIAB, recirculating throughout the mash, and temp regulated via PID.

From what I can tell, astringency is caused by both high temps and high pH. It is possible I had locally hot spots in the mash, I don't believe it was possible for the pH to be high enough to cause an issue.

Possible causes:
* thin mash: as this is BIAB and full volume on a low gravity beer, I mashed at ~4.41 qt/lb. is it possible that the thin mash pulls more out of the grain?
*SO4/CL ratio: pretty close to 2:1. Could this impact perceived bitterness? If I don't have the alpha acid to back up this ratio, could it come out as apparent astringency?
* hops: from the LHBS bulk bin.

 

[IslandLizard]

I took 2nd place, both judges rated it as a 32. [...]

Possible causes:
* thin mash: as this is BIAB and full volume on a low gravity beer, I mashed at ~4.41 qt/lb. is it possible that the thin mash pulls more out of the grain?
*SO4/CL ratio: pretty close to 2:1. Could this impact perceived bitterness? If I don't have the alpha acid to back up this ratio, could it come out as apparent astringency?
* hops: from the LHBS bulk bin.

Congrats with your 2nd place!
Although taking 2nd place with those notes and that score is a bit of a bummer, yes.
Are those judges experienced? Club judging can be a toss up at times. How many entries in your category?

Thin mash can possibly have something to do with it.
Higher SO4 accentuates bitterness, possibly perceived as astringency?
What should we visualize with hops from a "bulk bin?" How and where are those hops stored?

Is that the water profile before or after adding brewing salts?
Is the pH meter fairly reliable? As in, can it be off by more than .5, reading a pH of 5.8 at 5.3?
How is your water's alkalinity? That could play a role, although you don't have the cations to substantiate a high level.

 

[brewcat]

Too much special roast.

 

[IslandLizard]

Too much special roast.

I was thinking about that, but 4 oz at 50°L?
If Special Roast is like Brown Malt, which is known for some astringency, that could certainly explain it.

In one of my ESBs I just use:
6 oz C80
2 oz Muntons Dark Crystal (~170°L)
0.5 oz Carafa Special III (for color)
I steep on the side during the boil and add after the boil at 165F, so they never get boiled.
Alternatively, they could be added to the sparge, but they will be boiled, then, which I try to avoid.

 

[GoeHaarden]

I'm terrible with descriptors but when I think of "astringency" I think of a few things. One, which has already been mentioned about your malts. Two, your hops. What about trying to move your Magnum addition to FWH?

 

[Iseneye]

I can't see any acid addition. With full volume and potentially no acid your pH reading is suspect. Even with the roast grains I would expect your pH to be around 5.7 to 5.8.

 

[mwill07]

Congrats with your 2nd place!
Although taking 2nd place with those notes and that score is a bit of a bummer, yes.
Are those judges experienced? Club judging can be a toss up at times. How many entries in your category?

Thin mash can possibly have something to do with it.
Higher SO4 accentuates bitterness, possibly perceived as astringency?
What should we visualize with hops from a "bulk bin?" How and where are those hops stored?

Is that the water profile before or after adding brewing salts?
Is the pH meter fairly reliable? As in, can it be off by more than .5, reading a pH of 5.8 at 5.3?
How is your water's alkalinity? That could play a role, although you don't have the cations to substantiate a high level.

It was an internal competition - I think there were just 7 entries. I still feel good because my beer finished ahead of some really great Brewers. The judges were all BJCP certified.

Hops: stored @ LHBS in Tupperware containers in large fridge...not sealed packets.

Water: I'm listing after treatment. I dont recall at the moment exactly what I used, but my additions are limited to CaCl2, Epsom salt, gypsum, and baking soda. And, liquid citric acid. And a Camden tablet.

pH meter: 2 point calibration, calibrated that day. The pH matched very closely with predicted Bru'n water sheet.

 

[mwill07]

I can't see any acid addition. With full volume and potentially no acid your pH reading is suspect. Even with the roast grains I would expect your pH to be around 5.7 to 5.8.

I added liquid acid to bring the pH down.

 

[mwill07]

I was thinking about that, but 4 oz at 50°L?
If Special Roast is like Brown Malt, which is known for some astringency, that could certainly explain it.

In one of my ESBs I just use:
6 oz C80
2 oz Muntons Dark Crystal (~170°L)
0.5 oz Carafa Special III (for color)
I steep on the side during the boil and add after the boil at 165F, so they never get boiled.
Alternatively, they could be added to the sparge, but they will be boiled, then, which I try to avoid.

I'm lost. You basically mash the carafa special separately and don't include that wort in the boil?

 

[IslandLizard]

I'm lost. You basically mash the carafa special separately and don't include that wort in the boil?

Not mashed, steeped with the crystal.
And indeed, never boiled, just pasteurized for a few minutes when chilling the main batch.

 

[IslandLizard]

It was an internal competition - I think there were just 7 entries. I still feel good because my beer finished ahead of some really great Brewers. The judges were all BJCP certified.

Hops: stored @ LHBS in Tupperware containers in large fridge...not sealed packets.

Water: I'm listing after treatment. I dont recall at the moment exactly what I used, but my additions are limited to CaCl2, Epsom salt, gypsum, and baking soda. And, liquid citric acid. And a Camden tablet.

pH meter: 2 point calibration, calibrated that day. The pH matched very closely with predicted Bru'n water sheet.

Still, no clear evidence pointing to where the astringency is coming from. Since you can taste it too, not just the judges, it must be present. How about others, do they taste it? Have you noticed it before or in other beers?

That's not a very good way to store hops. Exposure to air/oxygen for extended times causes staling, loss of potency, aroma and flavor, and over time may become cheesy. Colder temps slow down hop oil oxidation somewhat, while pellets have a much smaller surface to volume ratio than whole hops, it's definitely not ideal.
Most of us store hops in a freezer, and after the bag was opened, they get either vacuum sealed or, if that's not available, as much air is expelled by squeezing or better yet, flushed with N2 or CO2, and resealed. Then back into the freezer.

Not saying the hops were stale, although stale hops don't make good beer, could they cause astringency or something perceived as such?

OK, you used an acid addition. Looks like you know what you're doing. Careful with Citric acid, though, it may leave a taste when used in larger amounts, although it probably doesn't apply to your case if alkalinity is low.
I think it's safe to assume that your pH meter is accurate. Those mash measurements are taken at room temps, I hope.

These beers don't have much to hide flaws behind.
Maybe it's in that special roast? Or the Maris Otter? Or the hops?

Do you mill your own? Is there extreme husk shredding? Maybe ease up on the crush a little. Very high mash efficiencies (85%+) have been related to astringency. It could be that simple.

Brew another batch with one or more suspect things changed out, see if it improves. Keep us posted.

 

[GoeHaarden]

Very high mash efficiencies (85%+) have been related to astringency.

Really? I've never heard this before but it makes sense. Interesting for sure. More and more it seems like in brewing your damned if you do, damned if you don't...I don't know what to believe these days!!!

 

[mwill07]

Still, no clear evidence pointing to where the astringency is coming from. Since you can taste it too, not just the judges, it must be present. How about others, do they taste it? Have you noticed it before or in other beers?

That's not a very good way to store hops. Exposure to air/oxygen for extended times causes staling, loss of potency, aroma and flavor, and over time may become cheesy. Colder temps slow down hop oil oxidation somewhat, while pellets have a much smaller surface to volume ratio than whole hops, it's definitely not ideal.
Most of us store hops in a freezer, and after the bag was opened, they get either vacuum sealed or, if that's not available, as much air is expelled by squeezing or better yet, flushed with N2 or CO2, and resealed. Then back into the freezer.

Not saying the hops were stale, although stale hops don't make good beer, could they cause astringency or something perceived as such?

OK, you used an acid addition. Looks like you know what you're doing. Careful with Citric acid, though, it may leave a taste when used in larger amounts, although it probably doesn't apply to your case if alkalinity is low.
I think it's safe to assume that your pH meter is accurate. Those mash measurements are taken at room temps, I hope.

These beers don't have much to hide flaws behind.
Maybe it's in that special roast? Or the Maris Otter? Or the hops?

Do you mill your own? Is there extreme husk shredding? Maybe ease up on the crush a little. Very high mash efficiencies (85%+) have been related to astringency. It could be that simple.

Brew another batch with one or more suspect things changed out, see if it improves. Keep us posted.

it's not a good way to store hops. Traditionally, I don't brew hop-forward beers so I haven't paid much attention to hops, just getting the bulk stuff from LHBS. Maybe it's time to invest in a vaccuum sealer, buying from Yakima or someone else, and re-sealing/freezing what I don't use.

On the acid: I misspoke. I use lactic acid, not citric. For this batch, I used 3.2ml.

pH: measurements were roughly room temp. I'm not going to say they were exactly 68 degrees, but certainly between 60 and 80. My process is to pull a sample in a shot glass and let it sit in an ice water bath for a few minutes with a thermometer. Once it gets below 80 or so, I pull it from the bath and put the pH probe in.

I mill the grain when I pull it at LHBS. Actually, I double-mill it to improve efficiency. This could be the issue.

My overall efficiency, by the way, came in at 79%. It would have been considerably higher had I squeezed the bag. There was a good bit of wort volume left in the spent grains that got tossed. I could have easily been in the 83-85% range.

Brewing again to see if that was the culprit is a good idea. Unfortunately, I will be traveling for work for the next couple of weeks, so I probably won't have a chance to replicate for a while.