Help with astringency

Hi all, looked at this forum many times, so time to join up...and ask for help.

I have been an AG brewer for over a decade. I am also a BJCP judge so I have few clues about what I am doing.

I moved to a new area a few years ago and since, I have had issues with astringency in some of my APA's.

I initially thought it was water chemistry, so got a reading:


Calcium
20-25ppm

Magnesium
0.7-0.9

Sodium
7.5-8.5

Sulphate
22-23

Chloride
11-13

Alkalinity (as CaCO3)
45-55

Hardness (as CaCO3)
50-70

pH
7.2-7.8

I used Palmers spreadsheet and made some water chem adjustments:
3gms Gypsum, 6gm calc chloride 2gms Epsom salt, 2gms Baking soda in 38L. This gave me a water profile rated balanced

Calcium (ppm)83 Magnesium (ppm) 6 Alkalinity as CaCO 81ppm
Sodium 22(ppm) Chloride (ppm) 88 Sulfate (ppm)87 Effective Hardness as CaCO3 63 ppm

I use Galaxy and other high AA hops in my beer, but in very low IBU. For example my last beer was only 22IBU at 5%. I use all my hops at 20min mark and later. I add a whole lot when chilling at 50 degrees, and I dry hop about 80gms.

The last three beers have all had and unpleasant (too me) astringency at the back of the palette in the aftertaste. I initially though it was hop bitterness and so scaled hops back, but last three beers using Galaxy and Cascade have all had it (even a beer coming in at 17IBU).

Any ideas on what could be causing this?

How are you sparging? If you are batch or fly sparging you might try acidifying the sparge water to about pH 6. I use Phosphoric but many use Lactic. Most wine/beer supply stores carry one or the other. Your water profile and additions look good to me. You might also only use the Baking Soda in the kettle and not the mash, just to rule out the bicarb as a problem (could potentially raise mash pH).

Have you measured your mash pH with the new water chemistry? You can adjust it with the same acids to about 5.4

Thanks Helli, I am no sparging at the moment. As I have a 66L tun I have been doing full volume mashes, so it can't be a problem of too hot water from sparge. My average mash s around 66degrees (have used two thermometers to double checked temp). I also use the ph 5.2 powder at recommended levels.

Any change to your milling procedure?

I recently had some astringency in a few batches that I'd never experienced before. I had switched to BIAB from a normal MLT and I guess I was squeezing the grains a bit. I stopped doing that and the problem was solved.

Also, I noticed the astringency on those batches faded with time. It could just be a bit "green"... are you sampling them earlier than normal for some reason?

Hopefully the OP is not adding baking soda to the sparging water. If anything, the sparging water needs a bit of acid to further reduce its alkalinity.

I can only assume that the OP was brewing a beer with some color, since adding alkalinity is called for with darker and more acidic grists. The problem with Palmers nomograph is that it tends to recommend far too much alkalinity than is actually required by the grist. Bru'n Water does not base its water adjustments based on the beer color. It uses estimates of the acidity of each grain used in the grist to predict the resulting mashing pH. It has proven to be more accurate in recommending appropriate alkalinity levels in the brewing water.

The 5.2 stabilizer could be a big reason why the beer flavor is off. It adds a very substantial dose of sodium to the water. That sodium can have an antagonistic result in conjunction with other ions in the water. In addition, it tends to move the mash pH into a range that is higher than desirable. In other words, it does not do what it purports to do. Drop the 5.2 if you want to brew better beer. The higher than desired mash pH can cause tannin extraction.

malticultural said:

. I also use the ph 5.2 powder at recommended levels.

Click to expand...

Definitely get rid of the 5.2 powder, and that might help.

I'm not an expert at all on BIAB/no sparge brewing, so could you give us a rounddown on that process? Do you mash with all of the brewing water, or to you add it later? I know many many brewers do mash with a full volume, but I've never gone over 2 quarts/pound and wonder about pH issues that way.

Thanks mabrungard I will give that a go.

Your water profile is fairly similar to mine:

• Ca 15.1 ppm
• Mg 3.0 ppm
• Na 8.3 ppm
• SO4 12.3 ppm
• Cl 15.2 ppm
• Alkalinity as CaCO3 44 ppm
• pH 7.3

(These are averages).


For my last brew (an EPA with 9.5 lbs M.O. and 8 oz Crystal 55L), I treated my water (close to 38 liters) with 11g CaSO4, 0.3g CaCl2 and 2 ml Lactic acid (88%).
From your notes, it seems that you don't like to accentuate your hops with sulfates, so you would probably want to reduce the gypsum, and increase to calcium chloride, but I agree with Martin that you don't want any baking soda.
I have never tried a no sparge brew, but I can get astringency with smaller grain bills by oversparging. I think (but could be wrong), that no sparge or batch sparge techniques should reduce tannin extraction problems, providing the pH of the mash is good.

As for the 5.2 pH stabilizer, I've used it twice, and both times, I got some very unpleasant off flavors which diminished after extended aging (about 9 months), but never disappeared. Stopped using it, and the off flavors disappeared.



Hope this helps,


-a.

Have you measured the PH of the mash? Calculators are great, but they aren't a replacement for actual measurements.

My water is very similar, with about 70 ppm alkalinity. It's a pain to get my mash pH right. Had to use 2-3% acid malt. Plus it drives up the sparge pH.

I have made so many beers that I have tended not to measure things so much anymore. I know my system and what it does (I still measure volumes, temps and gravity). Anyway, I went to get the ph strips to find that my daughters had used them all on the fishtank water! Not a happy daddy. So yes, the next step will be to go buy some more to eliminate that variable.
As for green beer. Straight from the hydrometer jar after brewing, and then during ferment and after kegging, the astringency was there. One of the Apas is now about 1 month old and still has it.

Do recognize that paper pH strips are next to useless in brewing. They do not tend to agree with actual pH meter readings when used on wort. The plastic Colorphast strips have proven to be reasonably reliable excepting that they tend to read about 0.3 units low.

I use the (semi) hard plastic individual strips from a lab supplies store.