Astringency

[Twah]

Hey everyone

I have a Blichmann RIMS electric system so I'm recirculating for the entire mash time.

I have been getting astringency in my last few brews and I'm trying to track it down. I had a dubbel that got a 41.5 in the 2nd round of NHC 2016. It had astringency initially but it sat for a good while and it went away and it was fantastic.

Just brewed a Kölsch in Jan '17 and it was horrible with astringency. It's been sitting in a keg for a few weeks now and it's getting better but not even close yet.

I brewed a Scottish 80/-ish two weeks ago and after i transferred it to kegs to age some in my freezer, it was astringent but not like the Kölsch but it was there.

So brew process is down and almost automatic, I check my pH on mash and it's spot on at 5.2-5.4 and I treat my sparge water to get my pH to around 5.8. I sparge at 169 during mash out for that just in case. This is all the same for the last few brews. Lautering is done with the BeerSmith recommended amount of water. I get very close on numbers and then add in carbon filtered water to boil kettle if my pre boil gravity is high.

I was browsing around reading things and I think it's my grain mill. After poking around the internet and then reading many of the brew books I have, I'm thinking my crush is too fine. Thinking about it, my flour level seemed pretty heavy so I'm thinking that my mill has really crushed the grain too much and has extracted the tannins that way. I'm pretty certain it's not my mash/sparge because that's all below 6 pH and under 170F.

I just tore my Monster Mill 3 roller mill apart. I adjusted it to .040 gap (per their starting out FAQ instructions). I had it down at .035 but haven't checked in a while so it may have been knocked and got closed even more. So changing that variable for my next brew coming up and hope it works. Do you think it could be Mill gap?

OR

Could it be my milling speeds? I put my drill on high torque so it can blast through the grain without problem but I wonder if I'm milling too fast and it's shredding the husks that way?


The more I think about it, I think it's the milling process.

Thoughts??? Appreciate any thoughts and thanks for any replies.

Twah

[BDawg]

Not a lot to add. You are checking the right things. pH, temp, and the mill are the most likely candidates.

Nothing to add about the mill. You are right, test a few settings. You should expect a drop in extraction efficiency, so
add a bit more base malt to your recipe to compensate.

Make sure your pH meter is properly calibrated. They are notorious for drifting.

Make sure your boil has enough movement that proteins and polyphenols/tannins will stick together and flocculate out.

Also, if your mash tun holds temp well without recirculating the entire time, try turning it off for the duration of the mash.
You have a RIMS, which heats the wort more directly than say, a herms would. I'm just speculating here, but IMO, there's no good reason to
continually expose the wort to heat if you can reconfigure slightly and leaving it alone will still hold the temp. Maybe insulation can help?
You can still do a short vorlauft before you start your sparge to set the bed and get a clean runoff.

You may want to also experiment with a slightly thicker mash. If you are up at 2 qts/lb, try dropping it to say 1.5.

I treat all the water in my HLT the same, so I sparge with exactly the same chemistry as I mash. I never have a problem with astringency that way.
You can always adjust with baking soda or more acid in the boil kettle at the end of the sparge if you need to.

The last thing would be to relax about maximizing your efficiency. That often can lead to oversparging.
Formulate for a bigger batch, so you aren't stretching to get every sugar molecule out to hit your gravity.
If you can get the correct # of gravity points into the boil kettle in LESS volume, you can simply top up your boil with plain water from your HLT.


So, as an example, if your recipe calls for 5 gallons at 1.050, that's 5 x 50 = 250 gravity points as the target.

the preboil target then needs to be say 7 gallons @ 1.036 (e.g, 250/7)

so you can use minimum grain and pull out 7 gallons at 1.036 where you extract everything and it all goes into the kettle
Or
you collect 6 gallons @ 1.042 then top up with 1 gallon plain water @ 0
Or
you collect 5 gallons @ 1.050 then top up with 2 gallons plain water @ 0
Or
4.5 @ 1.056 + 2.5 gallons @ 0
Or
4 @ 1.063 + 3 gallons @ 0

The bottom line here, you can add grain, collect a lower volume of higher gravity wort where you aren't over-extracting, and then top up with plain water to
hit the preboil gravity without over sparging.

HTH-

[mabrungard]

Yes, be careful to avoid oversparging. I've had to stop my runoff much earlier now with my new system and mill.

I purposely reserve about 1/4 to 1/3 of my sparging water volume and DO NOT add it to the mash in order to avoid running the final runnings at too low a gravity. That reserved water is added directly to the kettle to bring my pre-boil volume to the required amount.

My final runnings are now around 4 or 5 Brix. The typical brewing lore says to stop your runoff at a gravity no lower than 2 Brix. That didn't work for me.

[Charlie]

Not a lot to add. ....

(And then he added quite a lot. lol)

Astringency comes from tannins in the malt husks. BDawg"s post details precisely how to minimize that.

+1!

Charlie

[Twah]

Hey Bdawg, Martin, and Charlie

Thanks. Yeah process is dialed in, I check pH and all that stuff during mash and sparging. I'm really careful and anal about things so I check things. I use Martin's Bru'n Water for salt additions and it's always spot on. I basically have RO water coming out of my tap, it's so devoid of any minerals. I measured my run off and it was around 1.010 but that's interesting about what you said with regards to your brix is not 4-5ish. i'll check that on the next brew.

I think it was the milling. I had a lot of little bits and a lot of flour in my buckets after milling. I rebuilt the whole mill and gapped it up to .040 and I'm brewing this weekend and hopefully in a couple weeks I will know in a couple weeks time.

I haven't had my Kolsch in a couple weeks, hope the astringency levels go down some, my Scottish is still sitting in a 10 gallon keg doing a little aging and that will be moved soon to make room for my Alt attempt this weekend.

I'm trying to get this last brew in before my get taken down and out for probably the rest of the year, having neck fusion surgery mid march. So this will be my last brew for a long while which sucks.

I'll update when I get this Alt kegged and tapped and when I get my Scottish tapped too.

I appreciate the feedback and info.

[brewinhard]

+1 to astringency being linked to malt and high pH levels.

If all this has been checked, there is one option that you could try. Conditioning your grain prior to milling. This allows the grains to absorb a small amount of water, which lets the kernel swell a bit and makes for a coarser crush with no shredding of husks (which could leach polyphenols/tannins into mash) but still cracking the grains to allow the endosperm to be reached for conversion.

Easier than it sounds too.

1. Take a large plastic tote bottom.
2. Empty grains into it.
3. Mist top of grains with distilled/RO water.
4. Turn and mix grains with hand spraying more water on dry spots.
5. Mist and turn again.
6. Only about 1% water weight is needed for this and I usually spray and mix until only a few kernels stick to my palms and there is
very little dust (if any).
7. Let sit for grain to absorb water a bit prior to milling.
8. Dough-in immediately after milling.

[Twah]

Wet milling. That's definitely an option. I would have to upgrade my monster mill to stainless rollers so it doesn't rust them out but I've been thinking about doing that anyway. So if this doesn't work, I may try that if this doesn't work.

I do believe it's coming from milling the husks too much with just how much flour that I had in my bucket after milling.

Like JZ, Doc and Tasty always say, change one thing at a time.

Thanks!

[BDawg]

One last thing you can always try fining with polyclar, which is good at removing tannins from your beer.
Be careful to not overdo it, as it can reduce the hop profile as well.

HTH-