All Grain sour/astringent taste on pale IPA - Please help

[Mike Cole]

Hi there everyone, first post - Hi!

I have previously been brewing extract beers with steeping grains, attempting to create a hoppy, west coast style IPA. Although these beers have been drinkable they always had a mild sharpness to them that I equated to the extract.

Fast forward to now, I am attempting to brew all grain BIAB. My first attempted recipe was from the can you brew it guys - West Coast IPA by greenflash. This is mainly pale malt (86.4%) and 6.8% Carapils, and 6.8% crystal 40L. I fermented the beer with US-05 dry yeast (1 pack for around 3 gallons). I overshot my gravity a little and fermented it right down to 1010 at 18 degrees stable in a fermentation fridge controlled by an STC1000,

Everything looked great until I tasted the beer and there was the same sharpness/bitter/astringent flavour that has been there in small amounts with the extract beer but this time it was almost unbearable. Very hard to drink the beer, but behind that intense soury flavour I could tell the beer had fermented cleanly as if you could see past the sharpness the beer felt light and nice... hard to describe.

At any rate I have started to grow a little despondent, not being able to produce a decent beer. I went searching for the 50th time online and stumbled across some people talking about the effect of mash pH and tannin extraction. I downloaded my water report (Im in New Lynn, Auckland) and added the figures from the Huia water supply to EZ Water Calculator and it told me that I was just out of the 5.6 maximum pH range with the west coast IPA recipe and my unmodified water.

So my question is: Is this slight pH difference going to produce a strong astringent taste that I am experiencing in my very light in colour IPA? Or is it something else? I plan to add some minerals and lactic acid to the next brew and going to attempt a lightly lower gravity Epic Pale Ale clone to see if that improves it, but in your opinions is this the appropriate route to take? Im kind of at my wits end to be honest...

I cannot say for sure if what I am tasting is astringency. It is like this sharp, tanniny, bitter flavour that is really hard work on the tongue. Biting you could say.

Mash temps were 64 degrees C, and mashed for 75 minutes. No sparge or anything just normal BIAB, full amount of water. I did squeeze the bag but lots of BIABers say this is fine. Used a single fermenter (no secondary) and left it on the yeast for 14 days, with a 2 day crash cool period, then bottled. Sanitation practice is good, use starsan and keep everything very clean. No sign of infection either.

Also previous beers have been a little darker due to the extract colour along with extract pH range may have reduced this off flavour, which is now coming front and centre with pale, all grain brewing.

All thoughts would be most appreciated!

Thanks

[Peter Smith]

Bring a bottle along to the no 1 home brew tasting end of this month, some good Brewers come along who will be able to give good advice

I almost always put 1-2% acid malt in my light coloured beers to help lower ph. Is the flavour a sourness ? Seems you are describing a real biting bitterness note ... What hops are you using for bittering?

[Mike Cole]

This recipe called for Columbus and Simcoe at 60 minutes (small amount), then again at 30mins. Then Columbus, Simcoe, Cascade additions near the end of the boil, then a fairly big dry hop with Columbus, Simcoe, Cascade, Centennial and Amarillo.

The flavour I am fairly sure is not hops, as I can taste the hops almost a seperate flavour.Also this beer does not have the bite of early boil bittering hops as I intentionally backed them off to increase later flavour additions.

Good to know you tend to add acid to your light beers, next recipe I will definitely do the same and see if it helps. Also what is the No1 home brew tasting you speak of?

[Peter Smith]

its held at the number 1 Queen St bar here is the facebook group,  date for this month will be posted soon.  Basically a chance to taste other homebrew, ask questions etc and meet other homebrewers.  Often held in conjunction with a meet the brewer event at No 1 which is also great as you can talk to a pro.  Its very relaxed, more a meetup then an offical club etc

Good transport links as next to Britomart!

https://www.facebook.com/groups/no1queenstreethomebrewclub/

too hard to describe an off flavour, bring some along.   

 

[Kevin Sharp]

I've never BIABed, but there are a couple of things that occur to me.

Astringency comes almost exclusively from tannins, rather than any sort of fermentation bi-product. The source of tannin is usually grain husk, and (less commonly) lots of cone hops. Often tannins are extracted  by over-sparging - allowing your sparge water to get too hot or too alkaline. Obviously since you didn't sparge, "too hot" wasn't directly the problem. According to Weyermann there's no down side to adding acid malt in the sort of quantities that Peter suggests, so it's easy to cover the "too alkaline" angle. Acid malt is probably a safer bet that using acid to correct the mash pH unless you've got an accurate pH meter. I'm also wondering whether you're getting small particles of grain husk through the bag and into the pre-boil wort. If that's the case you'll definitely be extracting tannins in the boil. With my setup I monitor SG and pH during lautering, but I also taste the wort frequently. By tasting it's easy to tell  when astringency is starting to develop. You could do something similar to tell whether squeezing the bag is introducing problems - taste the first wort that comes out of the bag and then collect a sample as you squeeze the bag - see how they compare.

The second thing is that over attenuation will have the effect of exacerbating astringency. Your mash was at 64degC whereas the the CYBI recipe suggests 66.7degC. That's probably responsible for your over attenuation. The warmer mash also has the advantage that conversion is quicker so you can get away with a shorter mash - the CYBI recipe suggests 35 minutes.

A third thing just occurred to me. Is your water chlorinated? If so that would make astringency problems much worse. The chlorine reacts with tannins to form chloro-phenols which are usually described as having a band-aid flavour.

[Patrick]

Are you using the same fermenter for your BIAB brew as you used for your extract brews? Could be an infection there? Have you removed and cleaned the tap recently? (assuming you are using a barrel-type fermenter)

What are you using for sanitation?

[Mike Cole]

Yes I am using the same fermenter but my sanitation and cleaning practices are fairly good (I would have thought anyway). I use a 30L plastic fermenting bucket and dont use the tap to bottle with, choosing to use a racking cane instead? Do you think an infection is likely?

[Patrick]

Well if you were getting the same fault/sourness/astringency from the extract brew you need to look at what Has changed between extract and biab and what hasn't. It may be a process of elimination.

[Mike Cole]

Wow lots of good ideas in this post to think about. Yes I do not have a pH meter as yet so probably will use acidulated malt next brew.

The grain husk idea is a good one. The bag I use for BIAB has pretty large holes in it so this definitely could be happening. Its a shame as thats what I was sold by the home brew store for BIAB... would have thought they would have given me an appropriate bag. I do not see any grain husks themselves coming through but there could easily be grain husk flakes (ground up powder even) coming through as there was alot of trub in this brew. I guess next brew I will have to pay close attention to the squeezed vs non squeezed wort and see if there is a difference. I'm picking I should be able to taste the astringency before the boil if it has come from the grains and mash right as opposed to it developing during the boil as a result of small grain husk particles getting into the wort?

I think this beer may well have over attenuated but I was really happy to see my beer finally attenuating after having very low attenuation in my extract brews LOL. I guess it may have been better if it had finished at around 1014 or so? Although I was really shooting for a dry ipa... Would I likely get more astringency in longer mash? Would reducing it to a 35 minute mash reduce it? I would have expected that the tannins would either be extracted or not based on temp or pH, rather than a function of mash time? This is all new to me of course so your experience is really helpful.

Lastly I assume my water is chlorinated as most of Aucklands water is in some way. I have never noticed a chlorinated taste or smell about it though and so didnt bother with Campden tablets. This, along with some brewing salts, will be on the list to purchase next time I am at the home brew store. I could probably take a brew there too and see if the guy there can figure out what the flavour is...

[Kevin Sharp]

I'm picking I should be able to taste the astringency before the boil if it has come from the grains and mash right as opposed to it developing during the boil as a result of small grain husk particles getting into the wort?

It could be either, but it should be neither.

Would I likely get more astringency in longer mash? Would reducing it to a 35 minute mash reduce it?

Technically a longer mash does equate to more tannin extraction. That is too say that for a given pH and temperature there will be a given solubility of tannins in wort. However extraction doesn't happen instantaneously and in a short mash the tannin concentration may not  reach equilibrium. However at normal mash temperatures and pH the effects are very small and you're unlikely to notice unless you're doing something like an over-night mash. The main benefit of a short mash is convenience.

[Paul Finney]

Hi there Mike. 

One thing that pops out to me from your post is the squeezing of the bag. Just like you shouldn't squeeze a T-bag, you shouldn't squeeze a BIAB for the same reason that it will release tannins that you don't want. 

Most of the time astringency comes from grains and like Kevin says, over attenuation can bring them forward in the mouthfeel. 

One other thing, did you pitch direct or rehydrate? You don't say what your OG was but with an OG of 1.060 you would need 7grams for 3 gallons, and if you pitched direct you can kill up to half your yeast so you may have accidently underpitched slightly.

I would take Peter up on the offer of getting some other brewers to try the beer as they will have more experience of off flavours and where they come from.

[Peter Smith]

You may find that moving to a cheap cooler mash-tun with bazooka braid solves the issues as it will allow a Vorlauf to clarify wort and ensure husks and lots of small particles stay in the grain bed.  You wont believe how clear your wort is pre boil.  I too would not squeeze the bag as this is forcing all the little particles into your wort that you want trapped in the bed.

[Mike Cole]

This sounds like a great idea, but due to cash constraints at present this may have to wait a little while. Definitely an easy way to do it though whilst avoiding having to sparge!