Verdant IPA

[Alex Helbig]

Hi all. I’m trying to brew one of David Heath’s recipes forverdant IPA.


My first attempt at this recipe I aimed for a 10 L batch and significantly missed my gravity targets. Today I’m trying again - this time with a full-size batch. Once again I am well under gravity for this recipe.

The grain bill I’m using for this recipe is:
3.042kg Ale Malt
0.862kg Vienna malt
0.254kg Carahell
0.152kg Carapils
0.761kg Flaked oats (Uncle Toby’s Quick Oats)

My brewing system is a Brewzilla 65 L GEN 4. I have added the grist to 20 L of mash water at 65°C. Mashed for an 40 minutes at 65°, followed by 20 minutes at 68°, with an 10 minute mash out at 76°C. After mashing, I am sitting at about 1.053 SG.

Then used a rinse Sparge with sufficient water to bring the volume up to 26L. My pre-boil target is 1.050SG, but the measured value is only: 1.044.

Did a 30 minute boil. Volume reduced to 24L post boil and the measured gravity was 1.042. My target, however was 1.053.

Using Brewfather as the software solution for this brew.

So in short, it seems that I’m miles out from where I need to be. I have had reasonable success with this system until this brew. This is my first recipe using oats,I’m wondering whether the quick oats have not contributed to the sugars in the wort. If I remove the flaked oats from the recipe in Brewfather, then I end up about the gravity that I measured. It’s as if the oats weren’t there.

Would love some suggestions on how to improve my success.

Cheers,
Alex

 

[philrob]

Did you allow adjustment for the temperature of your wort in your readings?

 

[Tangle Foot]

Did you allow adjustment for the temperature of your wort in your readings?

Yes. Used a calculator to adjust for temperature. Most readings were taken two or three times to confirm.

Brewhouse efficiency is set at 75%. Although I’m not sure how dialled in that is yet, as I have only done 6 or 8 brews with the Brewzilla. Before that I have about 120 BIAB brews done in a 40 L Crown urn. Most of the brews I’ve done with the new system have been in the ballpark (3-5 gravity points above or below). But these last two , I’m so far out, I’m tempted to go back to my urn.

 

[Tangle Foot]

Yes. Used a calculator to adjust for temperature. Most readings were taken two or three times to confirm.

Brewhouse efficiency is set at 75%. Although I’m not sure how dialled in that is yet, as I have only done 6 or 8 brews with the Brewzilla. Before that I have about 120 BIAB brews done in a 40 L Crown urn. Most of the brews I’ve done with the new system have been in the ballpark (3-5 gravity points above or below). But these last two , I’m so far out, I’m tempted to go back to my urn.

Sorry for the change of account - I somehow ended up with two logins to AHB.

 

[Half Pint]

For one thing there’sa problem with your measurements as you’ve boiled off 2 litres and then measured a lower SG than you had pre boil.
I’ve heard of people having lower than expected mash efficiency from Gen4 Brewzilla. In those cases it seems like the problem was about the mash temperature ie the actual temperature of the mash was lower than indicated on the display. This was early days for the gen 4 and apparently something to do with the wort effectively channeling down the middle and not mixing very well. I have the impression that’s been sorted now so probably you’re all over that, but a colder than expected mash could explain your low numbers and poor mixing could explain the anomaly in pre boil and post boil SG readings

 

[Tangle Foot]

I do wonder about the mixing. Once you put the top plate in the malt pipe you can’t easily stir the mash. The recirculation pump is going the whole time, but there could be channeling. Back in my BIAB days I had no recirculation so I tended to give the mash a good stir every 10-15 minutes.

I’ve noticed a lot of variability between successive gravity measurements. So have typically taken the average of two or three measurements.

Also just remeasured the post boil gravity this morning. I’ve got 1.047SG. The hydrometer temperature adjustment calculator. I use is in the Brewer’s Friend app and I have noticed that I don’t think it’s very accurate at the higher temperature ranges. So I always leave my final sample to cool overnight and then I can take a room temperature gravity reading to accurately determine my OG for fermenting.

 

[Half Pint]

I do wonder about the mixing. Once you put the top plate in the malt pipe you can’t easily stir the mash. The recirculation pump is going the whole time, but there could be channeling. Back in my BIAB days I had no recirculation so I tended to give the mash a good stir every 10-15 minutes.

I’ve noticed a lot of variability between successive gravity measurements. So have typically taken the average of two or three measurements.

Also just remeasured the post boil gravity this morning. I’ve got 1.047SG. The hydrometer temperature adjustment calculator. I use is in the Brewer’s Friend app and I have noticed that I don’t think it’s very accurate at the higher temperature ranges. So I always leave my final sample to cool overnight and then I can take a room temperature gravity reading to accurately determine my OG for fermenting.

I have also noticed that BF temperature correction calculator doesn’t quite match up with my hydrometer at higher temps. I expect it’s calibrated for a quality instrument and my hydrometer is about the cheapest.

Do you have a separate thermometer for your mash or just the built-in temperature sensor?

 

[wide eyed and legless]

I think your post mash reading of 1,053 was out . Easily happens with readings post mash as the sugars are not evenly spread throughout the wort.
The ratio of a mash tun is 1-1.6 so they are shorter than they are wide, obviously on a homebrew scale that ratio wouldn't be acceptable because of storage space but I would like to see a greater diameter on a homebrew scale.
The Brewzilla is the narrowest diameter kettle so that is never going to help with efficiency, neither will having the top plate in situ.
Depending on my grain bill I will stir for 15 to 20 minutes keeping the tap fully open. You will feel the viscosity lowering as the starch converts to sugar then leave alone and let it settle.
Compaction of the grain at the bottom of the mash tun doesn't help the enzymes convert the starches, also don't take too much notice of David Heath and his 30 minute boils, it wasn't that long ago he was asking how to use the canned kits on the English forum.

 

[Tangle Foot]

.
Do you have a separate thermometer for your mash or just the built-in temperature sensor?

I have the Bluetooth thermometer so that I can measure temperature at the top of the malt pipe as well as the built-in.

 

[Tangle Foot]

don't take too much notice of David Heath and his 30 minute boils,

I normally do 60 minute boils. This is only the second time I’ve tried a 30 minute boil. Was wanting to see if I noticed a difference in the outcome.

 

[Dave70]

I took up 30 minute boils on the strength of David's vids, and things began to go wonky.
Switched back to 60 and consistency more or less returned. Dunno why.
Granted, I don't have a nervous breakdown over a couple of points here and there. I think the fermentation stage is where you need to be on point.

As WEAL said, put some elbow grease into the mash and keep the juices flowing.

There's also something to be said for leaning your system.
You need to be consistent before you can be precise, at least in my experience.

 

[clickeral]

Not sure if this will help as youve had success with previous brews but



Is what I use on mine, whats your crush like?

I don't use the top plate and I stir throughout the mash (roughly every 30mins or 15mins if shorter mashes) I found flow rate on the pump needs to not be full bore as well especially using the top plate as it really condenses the grain bed more then you want

Grain absorption is 1L/kg and I mash with circa 3.2L/kg

This is the standard brewfather profile I tweaked for 23L and no chill (I use 2x11L cubes for single batches)

If you were local id happily do a brew with you to see if it helps

Note I also have a big 3v that I switch to for doubles, triples, quad batches etc (150L ready to ferment volume is my max)

Oats can be tricky to mash, I try to add mine throughout mash in so they dont stick/clump together

 

[MHB]

Just a word about the Oats.

The worst possible choice would be "Quick Oats" they are often cut rather than rolled, which makes the starch less available. Rolled oats are fairly well gelatinised in processing but can still be less than fully available. Getting less from oats is a fairly common result.

I had a long hard look at this a couple of years ago while working on an ANZAC Biscuit recipe; this is where I ended up (yes got a beer that tasted like an ANZAC bickie).

1 Not all Oats are created equal.
Quick oats were the worst, selected for very high Glucan content, fine if you want to save 2 minutes at brekky time. Just not really all that good for brewing.
2 Rolled Oats, about what you would expect, good for porridge, fair for brewing...
3 Brewing Oats, surprise surprise the most expensive. Also worked the best. Selected for low gel forming so they don’t glug up your lauter but still give you all the things you are looking for in an Oat addition to your beer.

Making an ANZAC style beer I toasted my Oats to a golden brown and then "Digested" them.
That is mashed in about the same amount of milled malt and toasted oats at ambient (L:G ~ 3:1). Put a big pot on a small element on low heat so it rose in temperature very slowly (about 0.25 oC/Minute). This allowed all the enzymes to have a go on the way through to a simmer (100oC); mostly the Beta Glucan.
A 15 minute simmer meant the starch was also fully hydrated. The yield really was near theoretical and the mush was thin like a mash not like porridge at all.

If you want to use a cheaper alternative to proper brewing oats, at a minimum, use 2 volumes of water to 1 of oats and cook it like you would for breakfast. Best with some added malt. If you don’t want to add malt you really should do a Glucan rest around 46-49oC for 15 minutes or so as part of your mash regime.

Oats can bring a lot of nice silky mouth feel and body to a beer but they really are a bit of a PITA. It’s well worth using flaked Barley instead or even Flaked/Torrefied Wheat both bring a similar slickness and are easier to manage. If not quite as tasty.

Anyhow, have fun.
Mark

 

[Tangle Foot]

Hi Mark - thanks for all those suggestions. I didn’t know you could buy brewing oats. I’ll have to look at that at my LHB next time I shop. Meanwhile, I guess rolled oats are the way forward to get that silky oat impact. I’ll try the slow temperature rise as well like you suggested.
Cheers,
Alex

 

[Tangle Foot]

If you were local id happily do a brew with you to see if it helps

Thanks for the offer. Next time I’m in Victoria I might take you up on that.

Cheers,
Alex.

 

[Tangle Foot]

Is what I use on mine, whats your crush like?


Grain absorption is 1L/kg and I mash with circa 3.2L/kg

I’m also dialling in a new (MillMaster) grain mill at the moment. I used to use a fine crush for my BIAB days. Now with the BrewZilla, after a couple of stuck sparges, I’ve gone quite coarse. Not sure if the roller gap, but I’ve basically gone as coarse as possible while ensuring every kernel is cracked. The gap is probably about 1.0-1.2 mm - will need to measure.

Your grain absorption numbers feel high to me. Once again, this is probably something I should look more closely at.

Your equipment profile is similar to mine. I have a lower boil off rate - much more humid on the Gold Coast, and I run the heating element at 2500 W during the boil.

 

[clickeral]

I’m also dialling in a new (MillMaster) grain mill at the moment. I used to use a fine crush for my BIAB days. Now with the BrewZilla, after a couple of stuck sparges, I’ve gone quite coarse. Not sure if the roller gap, but I’ve basically gone as coarse as possible while ensuring every kernel is cracked. The gap is probably about 1.0-1.2 mm - will need to measure.

Your grain absorption numbers feel high to me. Once again, this is probably something I should look more closely at.

Your equipment profile is similar to mine. I have a lower boil off rate - much more humid on the Gold Coast, and I run the heating element at 2500 W during the boil.

View attachment 124884

Pretty sure im a 0.9mm gap but will remeasure tomorrow

I run element full power at Boil, and im a few M up sealevel so I think my boil temp is something like 99.4C

ive been in numbers on this profile but have found if I use different malt things can vary (I sparge to boil volume)

I use alot of voyager malt

 

[Tangle Foot]

Is there any chance the volumetric scale inside the BrewZilla is incorrect?

Today I tried another brew. Used a recipe I’m much more familiar with - LCBA clone. Done it many times BIAB - today tried a double batch in the BrewZilla. Good numbers throughout the brew. Right up until I transferred the wort to two 20L no chill cubes which I count on getting 22L into - and ran short - filled one cube and had the other was a litre or two off being full.

It seems that 48L in the BrewZilla does not full 44L in my cubes. I ran the BZ pump to fill the cubes to the point where I started to suck air!

Where’d the other 5-6L go?

Also note that my 1 hour boil on 100% power today only boiled off 3L! Is that what others get in Qld 90% humidity?

Cheers

 

[Half Pint]

Yeah for sure. You can’t trust those markings until you’ve established the accuracy by means of checking against a reliable measure.
I marked 1 litre weighed increments on my jug and that’s what I use to fill the Brewzilla. Mine is actually reasonably accurate but I’ve heard plenty of stories about units which are way off

 

[TwoCrows]

I got my volumes set as for 2 x cubes= 44 ltrs
4.2 ltr boil off
1.6 ltr trub
4 % shrinkage
post boil 47.5 ltrs

51.70 ltr at boil start
52 ltrs to be safe.

I also have a 1 ltr cube with the same 58mm lid as a back-up if my mash efficiency if higher and more water is added pre boil
9 kg of grain 70% eff, 38 ltrs mash and 24.5 ltrs sparge.