Vienna lager - better efficiency

[Chris79]

Hi all,

I brewed a Vienna lager on Wednesday. This was my second brew on my electric Cheeky Peak kettle (36 ltr, Keg king PID temp controller).

After I had completed my mash, I had a measured mash eff of 43%. You'll see from the attached my main grains were Vienna and Munich I (both Weyermann). When I had drafted the recipe, I had Pils in, but I took it out (just because, I think I was thinking I'd save some time on my mash/boil).

Just an overview of the process I followed for my mash: I started with 20 litres of water, then added the grains at 55 C, and straight up to 62, then 68, 72, and 78. Step time is in an attachment. After reaching 78, I sparged with about 9-10 litres of water (I've setup a hoist etc for my grain bag for my BIAB brewing).

Boiled for 60 minutes.

I did some research today. From what I could tell malts like Vienna have a lower diastatic power, thus a lower conversation in the mash. I thought the time of around 30 min at 63 or under would have worked fine for reasonable conversion.

I think the main thing I need to do next time is, add about 20% pils malt to have greater diastatic power in the mash. The second thing I thought I could do was, mashed with 15 litres, and sparged with 15 litres again. Thus making sure I get those higher concentrate sugars out of the mash.

Do you think those main two corrections should see me in the right direction of better efficiency?

Cheers
Chris

 

[Lyrebird_Cycles]

Typically both Vienna and Munich malts have a WK value around 200 - 250, and saccharification times of "normal"* to 20 minutes.

This means that in ideal conditions 100 g of malt has enough functional enzyme to convert starch to 200 - 250 g of reducing sugars. In rough round figures, if the average of your grain bill has 100 WK you will get complete conversion**.

Take home lesson: look elsewhere for your efficiency issues, there were enough enzymes and time to extract everything in your mash.


* the first iodine test in a standard malt analysis is done at 10 minutes, if it has converted by then saccharification is reported as "normal".

**Properly, you should get compete conversion with WK = % Extract * 1.1.
WK = 100 allows for a margin of error.

 

[malt junkie]

First and best place to look is your crush (no I'm not saying this because of any BB I'm doing , it's closed anyway) too course and enzimes and malty goodness can't release into the wort, too fine (even with Biab) and the sugars get trapped in a 'stuck' sparge. Second place to look is your water and PH in the mash. Just ball parking mine grabbed 5 points.

The other thing is don't chase numbers, once your in the mid 70's or better try and hit that number each time.

 

[Chris79]

Typically both Vienna and Munich malts have a WK value around 200 - 250, and saccharification times of "normal"* to 20 minutes.

This means that in ideal conditions 100 g of malt has enough functional enzyme to convert starch to 200 - 250 g of maltose. In rough round figures, if the average of your grain bill has 100 WK you will get complete conversion**.

Take home lesson: look elsewhere for your efficiency issues, there were enough enzymes and time to extract everything in your mash.


* the first iodine test in a standard malt analysis is done at 10 minutes, if it as converted by then it is reported as "normal".

**Properly, you should get compete conversion with WK = % Extract * 1.1.
WK = 100 allows for a margin of error.

So to summaries: I'm hearing a few things: in your opinion there was enough enzymatic power in this grain bill from my 75 min mash to get a reasonable conversion. Secondly, conversion may not have been complete? Lastly, I don't understand your second point in regards to your explanation at the two asterisk.

 

[Lyrebird_Cycles]

.....

So to summaries: I'm hearing a few things: in your opinion there was enough enzymatic power in this grain bill from my 75 min mash to get a reasonable conversion.

Yes

Secondly, conversion may not have been complete?

If you mean starch conversion: there is enough enzyme to convert available starch to soluble extract but this didn't happen so something is either limiting the availability of the starch or inhibiting the conversion. I think the former is more likely.

Lastly, I don't understand your second point in regards to your explanation at the two asterisk.

Not important, just use the short version.

The reason for the difference is that the test is based on enzyme extracted from 100 g of malt which is added to lab grade purified starch and the conversion is measured. Since in an all grain mash the malt is converting itself, what matters is the extract level of the malt (it won't have to convert anything else). The x 1.1 bit is because we measure reducing sugars and 100g of starch will produce ~ 110 g of reducing sugars. I said maltose originally, I'm not sure if that's correct as the test involved is Layne Eynon which responds to all reducing sugars.

 

[Chris79]

First and best place to look is your crush (no I'm not saying this because of any BB I'm doing , it's closed anyway) too course and enzimes and malty goodness can't release into the wort, too fine (even with Biab) and the sugars get trapped in a 'stuck' sparge. Second place to look is your water and PH in the mash. Just ball parking mine grabbed 5 points.

The other thing is don't chase numbers, once your in the mid 70's or better try and hit that number each time.

You know I was thinking about the crush yesterday/today. For now, I get my grains crushed by The Brew Shop, I do specific crushed for BIAB. I was wondering if the crush may have been too course (do you reckon brew shops just crush the same for BIAB and 3V system setups?). So, next time I was thinking I should ask them for a finer crush, and see what happens next brew?

My water is filter through this bench top filter. I live in Norwest Sydney.

I did add 5gm of Cal Chloride to the mash. Did test (yes with the humble ph strips) when the wort was room temp-ish. It was around 5.4.

Yep, agree to not get hung up on the numbers. But when my mash eff is dialled in. I'll aim to just hit those numbers again and again using Beersmith.

Cheers

 

[Chris79]

.....


Yes



If you mean starch conversion: there is enough enzyme to convert available starch to soluble extract but this didn't happen so something is inhibiting the conversion.



Not important, just use the short version.

The reason for the difference is that the test is based on enzyme extracted from 100 g of malt which is added to lab grade purified starch and the conversion is measured. Since in an all grain mash the malt is converting itself, what matters is the extract level of the malt (it won't have to convert anything else). The x 1.1 bit is because we measure reducing sugars and 100g of starch will produce ~ 110 g of reducing sugar.

alrighty, cool thanks!

 

[MHB]

The two things that do jump out are The Grind (as above), and Temperatures, Measuring something only counts if the thermometer is accurate - always well worth calibrating your thermometers and sensors.
The 68 and 72oC steps are probably redundant, or at least one of them is, just the one rest somewhere between the two would probably be enough.
The most obvious sign that the grind is way too coarse would be there are a large number of uncracked grains in the expended malt (they are pretty easy to spot) - more than 1-2 in a large handful of grist and I would be asking questions of the miller.

I sort of agree that perusing efficiency for its own sake is a bit futile for a home brewer, but 45%! yep something is wrong and the question well worth asking.
Mark

 

[Chris79]

The two things that do jump out are The Grind (as above), and Temperatures, Measuring something only counts if the thermometer is accurate - always well worth calibrating your thermometers and sensors.
The 68 and 72oC steps are probably redundant, or at least one of them is, just the one rest somewhere between the two would probably be enough.
The most obvious sign that the grind is way too coarse would be there are a large number of uncracked grains in the expended malt (they are pretty easy to spot) - more than 1-2 in a large handful of grist and I would be asking questions of the miller.

I sort of agree that perusing efficiency for its own sake is a bit futile for a home brewer, but 45%! yep something is wrong and the question well worth asking.
Mark

Thanks for the feedback.

Firstly, I'll request getting a finer crush of grains. I might even be able to double check that still, as the grains are in my compost!

I would be confident the temperature control should be ok, as it's the reasonable new Keg King temp control unit that controls the mash in the thermowell.

Maybe I'll just simplify the steps to 62, 68 then mash out at 78. Is that a better idea Mark?

Cheers

 

[Jack of all biers]

Don't be confident just because your thermo is new. Incorrect mash temps from dodgy thermometers is probably one of the most common causes of mash efficiency issues. Everybody does the same thing. They look at the grains, the crush, the mash schedule, think about adding enzymes and all sorts of things before they finally look at their equipment.

Test your thermometers by filling a glass with ice (crushed is best) then top up with cold water. Leave a few mins then test your thermometers. Should read 0. Then boil some water on the stove and test again. Should read 100. If they're out at either temp then they are out at mash temps.

I have a thermo thats out by 1 degree at temps below 70, but at 100 or more it's closer to 5 degrees out, so it's not always linear.

 

[manticle]

If you're going to step, go 62, 72, 78.

But crush and most importantly, calibration of measuring equipment (thermo, hydro/refrac) are first on the list.

 

[MHB]

To knock your efficiency down to 45% the malt would have to be barely crushed if at all (I think it was Thirstyboy who tried mashing uncrushed malt and got a similar yield), still well worth checking.
Uncrushed grain looks like little beads or pearls among the grist, ones you see them its pretty obvious. Spread a handful out on a dark surface.
Its rarely one thing that gives really low efficiency but rather a sum of several working together. If you are having a look at your expended malt look for dry bits (dough balls) and I always taste my expended malt (not perhaps out of the compost bin) if it tastes sweet - that's extract left behind - and it points to poor lautering...
Getting 80% plus isn't hard and usually is just getting the basics right, often hard when you are starting out to know what to look at first.
Mark

 

[Chris79]

I'll test my thermometer Jack / manticle. Good idea on how to go about that. I'll do that next time I have time.

I'll request a finer crush next time. How much finer do you think it might need to be? Or is that completely different for each mill?

To test my hydro is calibrated, can I use my filtered tap water or does it need to be distilled or RO water?

 

[Jack of all biers]

Filtered tap water is fine for Hydro calibration. Heck even unfiltered works for my hydro, but it's not an accurate lab grade thing. Test your thermometer first as you want to test the hyrdo calibration sample temp also to ensure it's not out from what your hydro is calibrated too (normally 20C, but sometimes 15C).

The mill setting is very dependant on the mill. You should talk to your HBS as to what they recommend. Unless they are careless, they will know very well what mill gap setting works and no doubt they use it for their own brews.

EDIT - as Mark pointed out, I'd check your last crush to see if there where any issues before getting a finer crush. A finer crush could cause you other issues like a stuck sparge, which is a frustrating PITA.

 

[Chris79]

Thanks Jack.

So, first I'll check the thermometer first in ice then boiling water. Re my hydro calibration. Are you saying it won't read 1.000 until I find its calibration temp of 20 or whatever it is.

Yes, I'll talk to Andrew at The Brew Shop, about what has happened.

My last crush, and first beer in this kettle was a Helles. my mash eff was 65% and that was with no spare. Yes, mainly pils malt.

 

[Tony121]

They are very helpful at the Brew Shop so it would be worth having a chat. I have not used them for crushed grain for a while, but when I did there was no issue so I would be looking at equipment/process as others have mentioned.

 

[Chris79]

These are my grains, I could get them out as ive just started composting again.

 

[manticle]

Thanks Jack.

So, first I'll check the thermometer first in ice then boiling water. Re my hydro calibration. Are you saying it won't read 1.000 until I find its calibration temp of 20 or whatever it is.

Yes, I'll talk to Andrew at The Brew Shop, about what has happened.

My last crush, and first beer in this kettle was a Helles. my mash eff was 65% and that was with no spare. Yes, mainly pils malt.

Calibration between 15 and 20 is pretty small variance. If you're reading very close to 1.000 within that range, the answer is elsewhere.

My money would be on calculation of efficiency being incorrect but go step by step and check all points.

 

[Chris79]

Understand what your saying Mark. I do have lots to practically learn. But I have been doing Biab over a bit over a year. Back on point, my last brew on this equipment had a mash eff of 65% with no sparge.

But I'm always learning from here and The Brewing Network especially. I will do the suggested tests above from Jack.

 

[Lyrebird_Cycles]

These are my grains, I could get them out as ive just started composting again.

Two things leap out: you have a very high percentage of whole corns, and there looks to be unmodified starch in some of the cracked corns (top right hand corner is an example).