Astringency? Mash Ph?

[bunkerbrewer]

Hi all -

I've only done 7 AG brews (all BIAB), and I'd promised myself that I wouldn't concern myself with water treatment (aside from Campden) for a long time.

But some of my beers are coming out "too bitter" (SWMBOs words), despite pretty sensible hop schedules and IBUs.

I don't have the worlds greatest palette, but I think I can detect what John Palmer describes as "dry, powdery" bitterness, like over-steeped tea ( http://www.howtobrew.com/section4/chapter21-2.html ).

The other clue is that it's much more noticeable with the pale ales than the porters and other dark beers - I've read that dark roasted malts lower the mash ph naturally - but it could be the more robust flavours of the dark beers mask other problems.

How do you folks measure mash ph and correct for it? Are the ph test strips any good? Am I barking up the wrong tree?

 

[jonewer]

You could try treating your water with CRS, this definitely made a difference for me when brewing pales. If you dont want to go down this route, you can get something called pH 5.2 which acts as a pH buffer for your mash. Not ideal but perhaps better than nothing.

You may also be over-sparging or sparging too hot. Maybe try sacrificing some efficiency for less astringency?

 

[bunkerbrewer]

Thanks for the tips.

Good point about temperatures. I don't sparge at all (BIAB) - but I do a mash out to 78°C, so maybe I'll aim for a lower mashout temperature next time.

I'll pick up some CRS next time I'm stocking up - is it reasonably straightforward to figure out how much to use?

 

[BarnsleyBrewer]

I'll pick up some CRS next time I'm stocking up - is it reasonably straightforward to figure out how much to use?

You'll need a detailed water report or an alkalinity testing kit..... Think they're around a tenner on fleabay..

BB

 

[jonewer]

The salifert test kits are dead easy to use. I avoided doing this for ages because I thought it intimidating but its really very simples.

 

[graysalchemy]

What you are suffering from is a drop in pH causing the tannin to be extracted from the grain husks. It could be that you have sparged to much, but I have never done BIAB so wouldn't know the procedure. Or more likely you have soft water, adding CRS will do the opposite to what you want to achieve it is an acid and will Lower the pH further.

Really you need to get a water chemistry from your water authority and also get a Safale Carbonate hardness/ Alkalinity test kit. Then use the water treatment calculator in 'Calculators' top left. This will tell you how much additions you need to make as per you beer style and brewlength.

Hope that helps

 

[jonewer]

What you are suffering from is a drop in pH causing the tannin to be extracted from the grain husks.

Ummm... really? All I have read states that tannin extraction occurs at higher pH's.

From beersmith

Tannins can be extracted by oversparging (continuing to sparge too long when mashing), sparging at too high a temperature (greater than 170 F or 77 C), or mashing at too high a pH level. pH levels above 5.5 are particularly prone to tannin extraction, with 5.1 or 5.2 being an ideal pH level during the mash. Any of these can lead to cloudy beer, chill haze and an astringent or bitter flavor in the beer.

How would sparging with water at pH of about 7 (roughly 100 times more alkaline than your mash) cause the pH to drop?

 

[graysalchemy]

silly me

Any way you still need to test your water chemistry before you start adding chemical additions :thumb: :thumb:

 

[bunkerbrewer]

Thanks everyone, I've found my Thames Water report, so I'll do some water testing and see what results I get. I'll try to figure it out myself - it'll stick in my head better that way :)

I may come back and ask someone to check my sums though...

 

[bunkerbrewer]

Sorry chaps, back already. Is this the right kit? http://www.ebay.co.uk/itm/SALIFERT-...0?pt=UK_Pet_Supplies_Fish&hash=item2eb3eeff52

 

[graysalchemy]

yes that is the one :thumb:

 

[Ceejay]

Might be worth having a listen to this too:

http://thebrewingnetwork.com/shows/798

 

[bunkerbrewer]

Thanks aleman. edit oops Thanks grayalchemy!

And cheers ceejay - I often listen to the Jamil Show on the way home - I'll grab that one for tonight's bus ride!

 

[mabrungard]

Yes, a drying sensation on the top and back of your palate are signs of tannin astrigency. Tannins are extracted when the mash pH rises about about 5.8. Mash temperature above 170F also tends to exacerbate tannin extraction, but its mostly pH that does it. The high mash pH will typically then result in a higher than desired wort pH in the kettle. High wort pH does cause hop bittering to become 'rougher' and less pleasant. The high mash pH also tends to extract more color and flavor from roasted malts too. All of these factors may be contributing to the poor flavor.

Knowing your water's ionic content is an important first step in understanding what you could and should be doing with the water for brewing. The simple aquarium test kits for hardness and alkalinity are quite helpful, but knowing all the major ions is important too. An alkalinity test kit is very helpful if the water supply's alkalinity varies. That is one parameter that you want to know relatively accurately.

The recommendation to use CRS is one option for reducing alkalinity. Unfortunately, it is not a cure-all and can actually lead to some other problems. The blend of sulfuric and hydrochloric acids used in CRS adds about 70 ppm of chloride to the water for every 100 ppm sulfate. That is fine if the tap water has low to moderate levels of those ions to start with. But if the water already has high levels of those ions, the CRS addition can produce excessive levels of those ions. The main thing brewers will want to avoid is elevating the chloride level about 150 ppm under any condition. That maximum allowable chloride level needs to drop further as the sulfate level rises. For the typical Burton style water, the chloride should be kept around 50 ppm since the sulfate level will be in the hundreds of ppm range. Using CRS does not allow the brewer to limit that chloride addition very well. Using either sulfuric acid, lactic acid, or phosphoric acid are better choices for neutralizing alkalinity when the degree of needed neutralization is high. From what I've seen of UK water reports, that is the case for a lot of the region. CRS is not ideal for all brewing.

I strongly recommend that brewers avoid the 5.2 Stabilizer product for any brewing usage. It is apparently a blend of sodium and phosphates that tend to buffer the mash pH to 5.8, not the 5.2 stated on the label. In high alkalinity water, it has not shown to be effective at reducing mash pH. It just adds a bunch of sodium to your beer and that is not good for flavor.

I suggest that you visit the Water Knowledge page on the Bru'n Water website to learn more about treating your water. The Bru'n Water software provides an effective way to assess what your brewing water adjustments will do for mash pH BEFORE YOU BREW so that you can adjust your approach to achieve a better pH outcome. It helps match the water treatment to the actual mash grist that you are brewing with.

I hope you resolve this flavor problem with your beers. With a few adjustments, huge improvements are likely.

 

[bunkerbrewer]

Thanks very much for the detailed advice - lots to think about.

Anyway, I've got my water quality report, plus some extra data from Thames Water (they were very nice - see this thread http://thehomebrewforum.co.uk/viewtopic.php?f=31&t=34343 )

I'm going to have a go with the water calculator for my next brew.

Re CRS and chloride - I'm already using Campden so will this negate this side-effect of CRS?

 

[mabrungard]

Thanks very much for the detailed advice - lots to think about.

Anyway, I've got my water quality report, plus some extra data from Thames Water (they were very nice - see this thread http://thehomebrewforum.co.uk/viewtopic.php?f=31&t=34343 )

I'm going to have a go with the water calculator for my next brew.

Re CRS and chloride - I'm already using Campden so will this negate this side-effect of CRS?

No, the Campden takes chlorine compounds, not chloride. It actually converts those chlorine compounds into chloride. But since chlorine compounds (disinfectants) are only present at around 2 ppm, the amount of chloride added from the reaction is somewhere around 2 ppm too. Not enough to concern ourselves with.

Did the Thames report give you Alkalinity? I know you said that carbonate wasn't reported.

By the way, its odd that carbonate is reported in any of these water reports. Carbonate is not present in significant concentration in drinking water. Its in the form of bicarbonate in typical drinking water.

Enjoy!

 

[bunkerbrewer]

Alkalinity - I think so - it's got hardness as CaCO3 which is 277mg/l (mean).

Based on limescale build up it seems to be Vinnie-b**tard-hard-as-nails-Jones hard water on the water hardness spectrum.

The forum calculator works with CaCO3, and CRS and Gypsum are pretty cheap, so I'll give it a go and see if it helps.