APA - Pilot Light Pale (Mosaic/Citra)

[ezraburke]

Brewday commenced on Sunday evening as planned - this session was about improving our lautering, sparging and efficiency.

We brought 19L of water to strike at 76c and a further 5L in our other pot for sparging to the same. Strike water overshot so proceeded to mash with a slightly higher temp of 72c rather than 68c. Honestly, not the end of the world and will give us a slightly more potent pale ale than we'd anticipated.

Lautering and sparging began after an hour of mashing and was for all intents and purposes fairly unremarkable. Recirculation was performed with our 4L jug and sparge water added periodically to draw out our 19L boil volume. The mash was stodgy like porridge and moving the wort around inside the tun was a little more difficult than we'd anticipated. Things i'd like to improve is the space utilisation in the mashtun and possibly a second outlet pipe to allow the wort to flow slightly more freely. I'll be looking into this in due course.

19L of wort drawn out and onto the boil. It was damned slow coming up to a rolling boil but, once again, unremarkable for the hour. Hop schedule as outlined in the recipe below. Boiloff brought us down to 17L as predicted (it's nice when you can anticipate these things...) and we cooled in the sink before dumping into our FV and pitching the yeast at 23c.

OG rang in at 1.050 - not quite the heady 1.064 we'd been aiming for and efficiency came in at 55% in the end. Our brew drops from 6.46% to 5.12% but, given that it's a fairly standard pale ale we're not massively bothered. The 83 IBU register seems ok too. The revised recipe (with altered efficiency and mash temp) below:

____________________________________________________________

Brew Method: All Grain
Style Name: American Pale Ale
Boil Time: 60 min
Batch Size: 17 liters (fermentor volume)
Boil Size: 19 liters
Boil Gravity: 1.045
Efficiency: 55% (brew house)


STATS:
Original Gravity: 1.050
Final Gravity: 1.011
ABV (standard): 5.12%
IBU (tinseth): 83.34
SRM (morey): 7.9

FERMENTABLES:
3 kg - German - Pilsner (60%)
1.5 kg - Torrified Wheat (30%)
0.25 kg - German - Carapils (5%)
0.25 kg - United Kingdom - Crystal 60L (5%)

HOPS:
20 g - Mosaic, Type: Pellet, AA: 11.7, Use: Boil for 60 min, IBU: 36.62
20 g - Citra, Type: Pellet, AA: 13.5, Use: Boil for 45 min, IBU: 38.78
10 g - Citra, Type: Pellet, AA: 13.5, Use: Whirlpool for 0 min at 80 °C, IBU: 7.94
40 g - Mosaic, Type: Pellet, AA: 11.7, Use: Dry Hop for 14 days

MASH GUIDELINES:
1) Infusion, Temp: 72 C, Time: 59 min, Amount: 24 L
Starting Mash Thickness: 4.8 L/kg

OTHER INGREDIENTS:
1 each - Whirlfloc, Type: Fining, Use: Boil

YEAST:
Mangrove Jack - US West Coast Yeast

 

[TheRedDarren]

When you say you mashed at 72 and expected a more potent ale, what do you mean?
That's a really high mash temp, that will favour the alpha amylase giving more complex sugars. In other words less fermentability.
is that yeast a good attenuator?

 

[ezraburke]

When you say you mashed at 72 and expected a more potent ale, what do you mean?
That's a really high mash temp, that will favour the alpha amylase giving more complex sugars. In other words less fermentability.
is that yeast a good attenuator?

Not sure about attenuation, will check. I fed the figures back into BrewersFriend and it reckoned the ABV would increase.

 

[TheRedDarren]

Sorry mate, I'm not following you here.
You put the figures back through your software and it said the abv would increase?
Increase because of what? High mash temp?

 

[ezraburke]

I think it was because of the higher mash temp, at least that was the output from the software. My understanding was similar to yours - lower mash temp = better fermentability ergo bigger ABV.

Think i'll run the figures again...

 

[TheRedDarren]

Alpha amylase activity falls within 66-72 degrees while beta falls within the 55-65 range.
Alpha will give more complex sugars that the wee beasties can't get their laughing gear around, leaving you with a fuller bodied, sweeter beer.
If your software is telling you you'll get a higher abv from a higher mash temp it's plain wrong I'm afraid fella. I'd consider getting new software.

Also, mashing at 72 is on the border of denaturing the enzymes, I'm not really sure what that will do to you brew. You took and og reading so I guess you have sugar...
Keep us posted mate, I'm interested to see how this turns out.

 

[TheRedDarren]

Also, the reason I was asking about the attenuation of that yeast is because if it's a high attenuator it may not be totally put off by the long chain sugars.
I just had a look at the Mangrove Jacks website and it says it's a high attenuator so fingers crossed for you there mate.

 

[ezraburke]

Alpha amylase activity falls within 66-72 degrees while beta falls within the 55-65 range.
Alpha will give more complex sugars that the wee beasties can't get their laughing gear around, leaving you with a fuller bodied, sweeter beer.
If your software is telling you you'll get a higher abv from a higher mash temp it's plain wrong I'm afraid fella. I'd consider getting new software.

Also, mashing at 72 is on the border of denaturing the enzymes, I'm not really sure what that will do to you brew. You took and og reading so I guess you have sugar...
Keep us posted mate, I'm interested to see how this turns out.

Oh aye, i totally get you on this - the fundamental science doesn't pass me by!

The original recipe was 70% efficiency mashing at 68c which resulted in a 6.46% ABV.

The only alteration to the recipe was the mash temp which rose to 72c.

If the software was still expecting 70% efficiency at 72c it comes out with an expected OG of 1.064 and resulting 6.52% ABV.

However as we both agree the higher mash temp would result in less fermentable sugars and likely lower efficiency and on that basis the lower OG of 1.050 would yield a calculated efficiency of 55%.

Does that sound like a reasonable theory for what happened here?

 

[CreweBrewer]

You'll still get enough sugars out of the mash to yield an OG of 1.064, just that not all of those sugars that are concentrated in the wort will be fermentable.

That's what I get from it...

Dave

 

[TheRedDarren]

Oh aye, i totally get you on this - the fundamental science doesn't pass me by!

The original recipe was 70% efficiency mashing at 68c which resulted in a 6.46% ABV.

The only alteration to the recipe was the mash temp which rose to 72c.

If the software was still expecting 70% efficiency at 72c it comes out with an expected OG of 1.064 and resulting 6.52% ABV.

However as we both agree the higher mash temp would result in less fermentable sugars and likely lower efficiency and on that basis the lower OG of 1.050 would yield a calculated efficiency of 55%.

Does that sound like a reasonable theory for what happened here?

Sorry dude, I didn't mean to show you how to suck eggs! :-)

I think you might be confusing fermentability with efficiency.

You have converted starch into sugar, albeit at a low efficiency (probably due to the high mash temp) but I'm worried about the fermentability of the wort.
I predict a stuck fermentation, maybe pitch some extra yeast.

Although saying all this, as we know it's quite hard to make bad beer and I reckon all will be well in two weeks time!

 

[TheRedDarren]

You'll still get enough sugars out of the mash to yield an OG of 1.064, just that not all of those sugars that are concentrated in the wort will be fermentable.

That's what I get from it...

Dave

Thanks Dave, that's what I was trying to say lol!

 

[ezraburke]

Thanks Dave, that's what I was trying to say lol!

Cheers Darren - it's a brand new style for us and i appreciate the your input, especially around the conversion issue!

I'll be checking the gravity later this week so will report back.

 

[CreweBrewer]

Thanks Dave, that's what I was trying to say lol!

I know mate. You could chuck a load of building sand in the wort - it'd up the gravity, but it won't ferment. For example...

Dave

 

[ezraburke]

I know mate. You could chuck a load of building sand in the wort - it'd up the gravity, but it won't ferment. For example...

Dave

Dave, what are the options for a stuck fermentation? More yeast, some DME or both?

 

[CreweBrewer]

To be honest with you mate I think you'll be fine. My crystal ball reckons it'll go down to 1.014 ish

Pitching more yeast won't ferment the unfermetable. Stuck fermentation is when the yeast has packed up, or there hasn't been enough healthy yeast to start with. Like setting out a huge dinner for 12 people and only three turn up.

Dave

 

[MyQul]

Also, the reason I was asking about the attenuation of that yeast is because if it's a high attenuator it may not be totally put off by the long chain sugars.
I just had a look at the Mangrove Jacks website and it says it's a high attenuator so fingers crossed for you there mate.

I dont always believe what its says on manufacturers web sites about attenuation an flocctuation

 

[TheRedDarren]

I dont always believe what its says on manufacturers web sites about attenuation an flocctuation

110% agreed. I was just hoping it wasn't a low or medium attenuator.

 

[ezraburke]

Gravtiy check #1 @ 1.020... will check again tomorrow night.

 

[ezraburke]

Lesson learned here is that when you say you'll mash at 68c you damn well mash at 68c. Fermentation has halted at 1.020 giving us a might 3.94% beer!

********.

We have a few backs of grains kicking around the shed (some maris otter, some special B, some carapils, some pilsner) that could be put together to form a wort. My question is should we consider making a small amount of wort (maybe less than a liter) with these remaining grains and pitch that in on top of the now fermented beer? Would this raise the ABV? Would it ruin it?

 

[CreweBrewer]

Leave it alone and chalk it up as a lesson learnt.

Dave