Astringency problem

[bustdbrewing]

I'm really stumped on this one.. I have brewed 3 pale ale batches in a row that have failed. All seem to have a very astringent flavor. My efficiency is 80%. The OG is 1.052 in a 12 gallon batch. The malt bill is 20lbs of base malt and 1lb of 60L. 6 ounces of hops in the boil including whirlpooling. I do not understand what I am going wrong. Any help would be appreciated.

[BDawg]

Astringency is usually sparge related. IMO, you should treat your HLT so that you are sparging with the same
water that you use to mash.

Check your temp and pH while sparging. It should never get above 170F and it should stay below 5.8 pH.
Also check your gravity when sparging. It should not get below about 2.5 brix (1.010)
If you hit those numbers and haven't hit your volume yet, then you should
stop your sparge and top up with plain water and/or DME to hit target gravity.
Adjust your recipe to add more base malt for the next time you brew that batch (and re-calc your efficiency given those pH and gravity limits).

HTH-

[bustdbrewing]

Astringency is usually sparge related. IMO, you should treat your HLT so that you are sparging with the same
water that you use to mash.

Check your temp and pH while sparging. It should never get above 170F and it should stay below 5.8 pH.
Also check your gravity when sparging. It should not get below about 2.5 brix (1.010)
If you hit those numbers and haven't hit your volume yet, then you should
stop your sparge and top up with plain water and/or DME to hit target gravity.
Adjust your recipe to add more base malt for the next time you brew that batch (and re-calc your efficiency given those pH and gravity limits).

HTH-

I can normally brew a 1.071 beer without issue using the same techniques. I use RO water and normally throw all salts into the mash tun and then sparge with RO water. Any ideas what is it would be become an issue now on a smaller beer?

[brewinhard]

What you are describing most likely sounds like over-sparging. If you don't have the astringency problem with your 1.070 beer but with a smaller 1.052 beer, then the extra grain involved in producing the stronger batch is giving you more grains to work with for the same amount of runoff to collect. In your 1.052 beer, you are still collecting the same amount of runoff but with less grains. As the sugars are rinsed out more thoroughly in the smaller beer, the pH will rise in your grainbed as the buffering capacity of the grains gets diluted with the extra sparge water used to collect your necessary boil levels.

As Bdawg stated, your best bet would be to check your runoff gravity and stop it when it hits around 1.012 or so (just to be safe). You would then need to use the rest of your sparge water to top off the remaining volume in your boil kettle. I ran in to this issue to before modifying my sparging technique.

[bustdbrewing]

What you are describing most likely sounds like over-sparging. If you don't have the astringency problem with your 1.070 beer but with a smaller 1.052 beer, then the extra grain involved in producing the stronger batch is giving you more grains to work with for the same amount of runoff to collect. In your 1.052 beer, you are still collecting the same amount of runoff but with less grains. As the sugars are rinsed out more thoroughly in the smaller beer, the pH will rise in your grainbed as the buffering capacity of the grains gets diluted with the extra sparge water used to collect your necessary boil levels.

As Bdawg stated, your best bet would be to check your runoff gravity and stop it when it hits around 1.012 or so (just to be safe). You would then need to use the rest of your sparge water to top off the remaining volume in your boil kettle. I ran in to this issue to before modifying my sparging technique.

I should clarify.... It is technically a 1.062 beer because I use corn sugar to get it to 1.070-ish. I normally collect 15 gallons whereas I collected only 14 gallons for the pale ale to drive down the efficiency. I put it in primary last night so I'm waiting to see how it turns out. I normally runoff through the ball valve on my BK. Is there an easy way to measure gravity without having to stop the runoff?

[Ozwald]

That larger grainbed is also going to provide a nice buffer, making it a little harder for the straight RO to change the pH. It will eventually happen, but it takes a lot longer.

Your runoff should be slow enough where you can collect a measurable sample, put the hydro jar in an ice bath & the large surface area will allow you to drop the temp pretty quickly to a correctable range. 1 point isn't going to be super critical at that point, so dropping it below 85F/30C should be good enough (but still run it through a calculator).

[bustdbrewing]

That larger grainbed is also going to provide a nice buffer, making it a little harder for the straight RO to change the pH. It will eventually happen, but it takes a lot longer.

Your runoff should be slow enough where you can collect a measurable sample, put the hydro jar in an ice bath & the large surface area will allow you to drop the temp pretty quickly to a correctable range. 1 point isn't going to be super critical at that point, so dropping it below 85F/30C should be good enough (but still run it through a calculator).

Should I acidify the sparge water then?

[Afterlab]

Astringency is usually sparge related. IMO, you should treat your HLT so that you are sparging with the same
water that you use to mash.

Check your temp and pH while sparging. It should never get above 170F and it should stay below 5.8 pH.
Also check your gravity when sparging. It should not get below about 2.5 brix (1.010)
If you hit those numbers and haven't hit your volume yet, then you should
stop your sparge and top up with plain water and/or DME to hit target gravity.
Adjust your recipe to add more base malt for the next time you brew that batch (and re-calc your efficiency given those pH and gravity limits).

HTH-

Agreed.

I can normally brew a 1.071 beer without issue using the same techniques. I use RO water and normally throw all salts into the mash tun and then sparge with RO water. Any ideas what is it would be become an issue now on a smaller beer?

This might not necessarily be related to a higher or lower gravity unless you brewed the exact same recipe with the exact same processes and found that the lower gravity is more astrigent. You may have just noticed more in the lower gravity because the flavor threshold was lower.

My question without knowing your equipment setup is that it sounds like you're looking to finish up the boil with 12 gallons of wort and then putting that wort into a (2) 5 gallons vessels or (1) 10 gallon vessel? If that is the case, how come you have such large preboil volumes of 14 and 15 gallons? To me I look at that and think you're potentially using too much water and diluting your sparge more than you think and you're having to use a ton of energy to get that boiled down to your target volume. With a large volume of untreated RO sparge water you're not doing yourself in favors in avoiding tannin extraction. Definitely acidify your sparge water.

On my system I look to finish up with 12 gallons post boil and I start with 13 gallons (for a 60 minute boil) or 13.5 gallons (for a 90 minute boil) at the beginning of the boil and look to lose .5 gallons every 30 minutes. I acidify and add salts to my strike and sparge water and haven't had any issues. Typically 11 gallons of water gets used for strike water and 6-7 gallons gets used for sparging. During the mash the grains will lower the pH but when you add untreated RO sparge water at the end of the process the pH lowering ability of the grains has already been diminished so you need a helper to aid in maintaining that low pH during the sparge.

Astringency can also come from your water profile, the hops and the amounts you use and yeast in suspension post fermentation. Can you describe what the astringency taste like?