Efficiency

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Philip321
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Efficiency

Post by Philip321 » 1 year ago

Attached is the BIABacus

In my 100 Litre electric kettle I brewed a Bag End Bitter, here is the link. http://biabrewer.info/viewtopic.php?f=7&t=1391

My problem is, The Gravity of Ambient Wort @ 20c = 68F was only 1.034 and the recipe requires an original gravity of 1.043
I mashed at 66c = 150.8F for 90 minutes. I did raise the temperature to 70c = 158F before striking as it is quite a big bag full and it did drop to 66c

I checked the temperature halfway through the mash and raised it back to 68c
I mashed out at 78c = 172.4F for 10 minutes
I boiled for 75 minutes (The recipe calls for boiling for 60 minutes)
My desired volume into Fermenter (VIF) was only 40 Litres so there was plenty of room in the kettle for the grains to mash properly.

Do you think the recipe is at fault or my brewing?
How can I improve the OG to 1.043 on my next brew day?
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Post by ShorePoints » 1 year ago

How long did it take to add all of the grist?
Your strike temperature was 70 degrees C to accommodate the large grain bill. That meant that the earliest portion added saw hotter water than the last portion. Was it hot enough for long enough to harm the alpha enzymes in a big portion of the total grain bill such that they were not available throughout the mash? If you get terrific body in the final beer, then maybe so. Just a theory based on thinking about how what the first particle experiences is different to what the last particle experiences. It would have been more difficult to strike at 68 and heat the whole mixture from where it ended (with stirring) to your desired mash T.
Others will ask if your grain weight was accurate, but that's not all that could be at play. There are upper limits to BIAB.


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Efficiency

Post by Contrarian » 1 year ago

The size of the mash shouldn't be a problem. I make batches that size in a 70L pot all the time and don't have those sort of problems, especially with a moderate target OG.

I'm on my phone so can't see the file but from glancing at the original recipe the grain weight seems ok but maybe a little on the low side for the efficiency I get with my system.

The most important thing to realize is that the main benefit of efficiency is being able to copy recipes for your system, a bit of extra grain here or there doesn't make a big difference!

The first place to start is measurement. Check thermometers, scales and volume measurements as well as whatever you are measuring gravity with and if they are all ok you can start looking at other factors like water chemistry.


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Post by Philip321 » 1 year ago

Hello ShorePoints,
Thank you for your reply.
I raised the temperature to 70C and then put my bag in the strike water. Then I poured the grist and stirred it in a bit at a time.
The strike water could not have been 70c but a little lower by the time I had put the bag in and started to pour the grist.

Would 70c really harm the alpha enzymes?


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Post by Philip321 » 1 year ago

HELLO Contrarian,

You've hit the nail right on the head.
Fortunately I started with a new 25 Kilo bag of Marris otter so I weighed it and I have only used 5.1Kg. I should have used 6.899kg
No wonder the gravity is only 1.034.
Bye the way I weighed an unopened 25kilo bag of Golden Promise and it weighed 25.66kg with the bag.

Now I have 40 Litres of beer that is only 3% (1034-1010 Divided by 7.46 = 3.21%)
I'll have to make an extra strong brew and mix it with this weak one.

Thank you for your reply.

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Post by ShorePoints » 1 year ago

Philip321 wrote:Hello ShorePoints,
Thank you for your reply.
I raised the temperature to 70C and then put my bag in the strike water. Then I poured the grist and stirred it in a bit at a time.
The strike water could not have been 70c but a little lower by the time I had put the bag in and started to pour the grist.

Would 70c really harm the alpha enzymes?
I believe it is getting near the edge of deactivation and if your thermometer gave a number much lower than the actual temperature, then it would be a real consideration. In the present case, "others" in the form of Contrarian's reply nailed it as a weight problem. The simplest answer is the better one.
Last edited by ShorePoints on 19 Jun 2016, 18:23, edited 1 time in total.


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Post by PistolPatch » 1 year ago

Philip321 wrote:HELLO Contrarian,

You've hit the nail right on the head.
Fortunately I started with a new 25 Kilo bag of Marris otter so I weighed it and I have only used 5.1Kg. I should have used 6.899kg
No wonder the gravity is only 1.034....
That's great you have found the problem Philip :salute:.

Incorrect weighing is the most common reason for actual kettle efficiency being lower than the estimated and it's very easy to do. Here is a checklist of this and other reasons that can cause low efficiency.

Because it is so easy to make an error in weighing, I always employ a double check. In other words, I'll weigh the grains individually but, then I'll also weigh the total grain bill. (Basically, you need to know the weight of your bucket or whatever you are pouring your individual weighed grains into.

I also try to employ double-checks on kettle efficiency (volume and gravity) readings as, strange though it seems, occasionally, you just get weird readings. (I see that in that checklist, I didn't mention "hydrometer jar too narrow" or "wort not mixed well before taking gravity sample," which are other easy errors to make.

A good mantra is, "Never trust a single reading on a single brew." (Mind you, that advice doesn't go down too well sometimes - see this and the subsequent post :shock:). You've got a few brews under your belt from memory so when you get a sudden "kettle efficiency" shock as you have on this brew, if you don't have the double-check on weighing grains up your sleeve, you can be confident the problem was with that or an unreliable gravity sample.

...

One other thing I want to expand on that has already been mentioned above is your strike temperature. Check out the second line of Section E. It says strike at 66.6C to achieve your mash temp of 66C. Striking at 70C is definitely too high. In fact, if you waited until your water reached 70C and then immediately mashed in, you'll have an even bigger problem. Here's why...

Large/Heavy Kettle Set-Ups Continue to Heat even after Flame is Turned Off

I have gas-fired 70L kettles. Let's say I wanted my strike temp to be 67C. If I turn the flame off as soon as it gets to 67C, if I let it rest, then agitate the water, it will be at around 69C. So, I must stop it a bit below the temp I want, and let it rest for 5 mins before striking.

Applying heat during the mash on these heavy set-ups has similiar problems. Let's say I am mashing at 66C and then 30 mins into the mash I notice it has dropped to 64C. Once again, if I agitated and applied heat until it returned to 66C, after five minutes of me having the flame off, I'll see it has jumped to 68C. You'll notice it takes ages to go from 64 to 65 but then things accelerate rapidly (because, that first period of time was spent on heating your kettle stand and kettle up).

Basically, always err on the low side of things and definitely let your kettle settle down for five minutes before striking.

As mentioned, my kettles are 70L while yours is 100L. This means the problem above will be more pronounced with yours especially if brewing small batches in the large kettle.

...

Please let us know how the beer tastes though. These "errors" can teach us all a lot. For example, your high mash temp could well give you a very well-balanced low alcohol beer. It's quite possible you'll find the end result a great drop.

:drink:
PP
Last edited by PistolPatch on 19 Jun 2016, 19:11, edited 1 time in total.
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Efficiency

Post by Contrarian » 1 year ago

Glad it turned out to be something simple, fortunately it normally is and from my perspective even the most accurate him brewer still incorporates plenty of unknown measurement errors into every brew, fortunately it is a fairly forgiving process that allows us to make good beer anyway!

If you don't want to make another brew to blend and have hopped the beer as if it was 1.045 you could always just add some DME to bring the gravity up. It won't have a massive effect on flavour and will balance things out a bit.

If you have a couple of cubes you could always try one with DME and one blended and see what you like more.


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Post by Philip321 » 1 year ago

Thanx for the replies.
PistolPatch, I will definitely take your temperature/ striking and continued kettle heat rises into consideration and double check the weights.

I will make another batch the same size but make it 5.5% alcohol strength and mix it pint bye pint.

Bye the way when I really made a mess of my hop bill on two batches last year (one miles to little hops and one miles to much hops) I mixed them pint by pint and it was a great drop of beer.


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Post by PistolPatch » 1 year ago

Great point on the blending of beers Philip :salute:.

Gordon Strong, who won champion brewer in US for several years, besides entering a lot of beers, also blended many of them. You should never be scared to blend and I'm impressed you have already done so.

Top job ;).
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Post by katandadd » 10 months ago

...

One other thing I want to expand on that has already been mentioned above is your strike temperature. Check out the second line of Section E. It says strike at 66.6C to achieve your mash temp of 66C. Striking at 70C is definitely too high. In fact, if you waited until your water reached 70C and then immediately mashed in, you'll have an even bigger problem. Here's why...
Hi PP,

You say striking at 70°C is to high, however BIABacus always tells me to strike at 71.2 or 72 depending on the size of the batch. I usually have around 5kg of grain at 18 °C, strike water around 32L. I have been doing this now for some time and I have just finished my 59th batch yesterday. Once I have added the grain I always end up at my mashing temp of 68°C.  
Should I be striking at a lower temp and them raising up to 68°C?

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Re: Efficiency

Post by Lumpy5oh » 10 months ago

What I think PP was saying is that if your water reaches 70 and you turn the heat off the residual heat of your kettle will actually raise the water temperature more. Did you fill in section E on the biabacus with your grain temperature? That will tell you what strike temperature to use. My kettle is pretty thick so I stop heating and couple degrees lower to compensate for the kettle heat.
Last edited by Lumpy5oh on 03 Dec 2016, 08:25, edited 1 time in total.
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