Beer never quite reaching final gravity

[kickz28]

Hi,

I have an electric herms brewing system, basically a clone of Kal's electric brewery. I feel like my beers never quite reach the expected final gravity and I was wondering if anyone had any tips or advice. Here's a short description of my process:

Unlike Kal, I preheat my strike water in the mash tun using the HERMS coil. This means that when I mash in, my mash is about 5-10 degrees cooler than intended mash temperature. I simply recirculate until it reaches it's temperature and then I start the 60 minute timer.

I always do an iodine test and it always passes.

I checked my Thermapen in an ice bath and boiling and it's accurate. I also checked my mash temp using a different thermometer and it's right on.

Here are my two latest batches:

1. APA: 95% Maris Otter (Crisp), 5% Crystal 75, OG: 1.054. Mash 152F
2. Hefeweizen: 47.5% Wheat Malt, 38% Pilsner Malt, 6.5% Vienna Malt, 3% Munich malt, OG 1.054. Mash 152F

In the APA, I pitched two packets of US-05. In the Hefeweizen, I pitched one packet of WLP300, with no starter.

I feel like both batches should have finished at around 1.010. But they both finished at 1.014. I know this is not a huge problem, but I can't help but feel like they should have finished a little bit lower.

Before pitching, I shake the carboy for a minute or so creating a lot of foam. I usually make a yeast starter for liquid yeast but for a Hefe I didn't because I read you should stress the yeast a little bit to get a little extra banana flavour. And the yeast was fresh so I thought it would be fine.

I fermented both at 68F, increasing slightly to approx 70F after a week to try and help it finish.

Fermentation for both batches seemed very vigorous, with lots of blow off and 3-4 bubbles per second.

Both batches were left untouched in the carboy for 3 weeks before checking the FG.

I'm not sure what else I can do or check. It seems like I'm doing everything right, yet the beer doesn't want to go down any lower.

Anyone have any tips or any idea what I should do?

BTW the post was for my last two batches, but for the last 2 years or so it seems that my beers never quite reach the FG I expect it to, it's always 2-3 points high.

(BTW I have 2 hydrometers and I checked them both with distilled water and they're accurate)

Thanks!

 

[doug293cz]

You could try lowering your mash temps a couple of degrees, and/or extending your mash time in order to get more fermentable wort. Your iodine test can show "completion" before your wort has reached its maximum fermentability.

Brew on

 

[cannman]

Hi there

There are actually a couple of things that you can change in your process to help you reach the attenuation you want.

1) Make a starter. I know that you are using dry yeast but you can still benefit from a yeast starter. A lot of people will say "nah don't make a starter with dry yeast, the manufacturer makes lots of efforts to make sure you can direct pitch etc. etc." and this is true. You can direct pitch and make beer (just like you did!) but you aren't getting the beer you WANT. so make a starter.

2) Oxygenate. Do a bit more than shake the carboy. Infuse with oxygen. 1L for 2 min is a good start. Let me know if you need direction on this or how to etc.

3) Something to consider is that the higher the mash temps, the lower fermentability you have.

4) How are you controlling your fermentation temperature?

5) Hydrometers need to be read at a specific temp (somewhere around 68f) you need to make sure your sample is at the right temp for your hydrometer. You can find the specific temp on the little paper that is inside the hydromerter

 

[Magnus314]

Okay, not being a jerk - have you mashed lower to see if that helps?

Your results have been very consistent, so dropping your mash temps a little seems like an easy easy test/fix.

 

[kickz28]

You could try lowering your mash temps a couple of degrees, and/or extending your mash time in order to get more fermentable wort. Your iodine test can show "completion" before your wort has reached its maximum fermentability.

Brew on

Well for these last two batches I mashed at 152, but these are not the only 2 batches that finish a bit high. Most of my beers are between 150 and 152. The Hefe was mashed for 90 minutes. 150-152 is already on the low end right?

1) Make a starter. I know that you are using dry yeast but you can still benefit from a yeast starter. A lot of people will say "nah don't make a starter with dry yeast, the manufacturer makes lots of efforts to make sure you can direct pitch etc. etc." and this is true. You can direct pitch and make beer (just like you did!) but you aren't getting the beer you WANT. so make a starter.

As I said above, I usually always make a starter with liquid yeast, my gravity still usually finished a little bit high.

2) Oxygenate. Do a bit more than shake the carboy. Infuse with oxygen. 1L for 2 min is a good start. Let me know if you need direction on this or how to etc.

This is the next thing I want to try. I have all the equipment, just need to set it up for the next batch. I haven't tried it yet simply because lots of people seem to be fine without oxygenation.

4) How are you controlling your fermentation temperature?

I have an STC-1000 hooked up to a heating belt and fermentation fridge. The probe is taped to the carboy/bucket and insulated with a piece of foam.

5) Hydrometers need to be read at a specific temp (somewhere around 68f) you need to make sure your sample is at the right temp for your hydrometer. You can find the specific temp on the little paper that is inside the hydromerter

Yep I made sure to check that.

Okay, not being a jerk - have you mashed lower to see if that helps?

Yeah, just not sure I want to go much lower than 150. I know some people will go as low as 148 or so, but I feel like this would be in situations where you want a super dry beer which is not really what I'm trying to achieve.

In your experience, looking at the recipes I posted above, would you expect to finish at 1.014 or lower?

 

[schematix]

I think your numbers are in line with expectations.

The only time i got attenuation like what you desired was when i had a faulty hydrometer - it wasn't real.

Ferment at 148 for 90 minutes and you'll get your 80%+ attenuation.

 

[Magnus314]

When I moved from fresh liquid or even dry yeast to starters or slurry, my FG's dropped several points.

 

[theseeker4]

Yeah, just not sure I want to go much lower than 150. I know some people will go as low as 148 or so, but I feel like this would be in situations where you want a super dry beer which is not really what I'm trying to achieve.

In your experience, looking at the recipes I posted above, would you expect to finish at 1.014 or lower?

I don't get the aversion to mashing lower. You have results that are not where you want them, you have an option to move your results in the direction you want, but you are hesitant why? There is nothing magical about 150 or 148. If your wort is not as ferment able as you like at 152, try 150. Still not there? Try 148. Your wort will not go from finishing too high to finishing way too low just because you drop your mash temp a couple degrees. Slightly decreasing your mash temp won't move your beer from a little too high, to "super dry".

 

[kickz28]

I don't get the aversion to mashing lower. You have results that are not where you want them, you have an option to move your results in the direction you want, but you are hesitant why? There is nothing magical about 150 or 148. If your wort is not as ferment able as you like at 152, try 150. Still not there? Try 148. Your wort will not go from finishing too high to finishing way too low just because you drop your mash temp a couple degrees. Slightly decreasing your mash temp won't move your beer from a little too high, to "super dry".

I don't have an aversion, it's just that when I look at recipes, they always seem to finish lower than mine, at similar OG's and similar or even hotter mash temps. Here are some examples:

https://www.homebrewtalk.com/showthread.php?t=35679

OG: 1.052, FG: 1.009, mash at 153

And another:

https://www.homebrewtalk.com/showthread.php?t=240710

OG: 1.052, FG: 1.009, mash 152

Then some APAs:

https://www.homebrewtalk.com/showthread.php?t=32939

OG: 1.055, FG: 1.012, mash 153

https://www.homebrewtalk.com/showthread.php?t=369668

OG: 1.055, FG: 1.010, mash 154

http://www.theelectricbrewery.com/forum/viewtopic.php?t=24947

OG: 1.056, FG: 1.010, mash 152

So yeah I can probably lower my mash temp to 148 and maybe my beers would finish drier, but I can't help but think that there's something else going on.

 

[cannman]

For what it's worth, when I first started AG and mashing, I would need mash at say 152 like you do. But in getting there, my temp would climb climb climb and once I hit 152, even though the flame was out, temp was till rising more more and more! I'd add cool water to control it back down... but sometimes it was too late. If you have experienced this, you might be denaturing your enzymes needed for proper conversion right from the get go. Even though you sit at 152 EVENTUALLY you are still lagging behind what you are hoping to extract and have made a ton of unfermentables (tricks hydrometer on OG, not on FG)...

So if you still think you've mastered all the suggestions put forth before you from the members, try investing in ways to better control your rise.

 

[kickz28]

For what it's worth, when I first started AG and mashing, I would need mash at say 152 like you do. But in getting there, my temp would climb climb climb and once I hit 152, even though the flame was out, temp was till rising more more and more! I'd add cool water to control it back down... but sometimes it was too late. If you have experienced this, you might be denaturing your enzymes needed for proper conversion right from the get go. Even though you sit at 152 EVENTUALLY you are still lagging behind what you are hoping to extract and have made a ton of unfermentables (tricks hydrometer on OG, not on FG)...

So if you still think you've mastered all the suggestions put forth before you from the members, try investing in ways to better control your rise.

Thanks for the suggestion. I don't think this is the problem because I use a HERMS coil to get to temp. Next time I brew I'll make sure to check the mash in a few spots though.

Next time I brew I'll also ferment a liter or 2 on the stir plate to do a forced fermentation test.

I will also make sure to make a good sized starter and get my oxygen system up and running.

 

[LarMoeCur]

Doing a 90 minute mash at 152 is the exact problem.

Beta enzymes (which make ferment-able sugars ie. maltose) work best between 131-150 F. At 149 beta enzymes start to denature at an alarming rate (roughly 5 minutes). 80% conversion happens in the first 30 minutes and only 5-10% after 30 up to 60 minutes. After that you get about 1%.

Now alpha enzymes work at 154-162 F. Alpha enzymes are the big choppers. They bust apart starches into smaller parts for the betas to covert.

So, you are mashing to high and for to long. At 30 minutes your about out of beta enzymes but your alphas are still in full force. At 60 minutes only the Terminator betas are crawling around but doing some conversation but almost nothing. Mean while your alphas are still chopping away making unfermentable sugars.

Now, depending on the beer style. I would lower the mash temp to 146-148 F and mash for 60-75 minutes. I would for sure do a mash out to stop all enzymes mainly the alphas. Or you could mash at 152 F for 60 minutes and make sure you do a mash out to stop the alphas, but I'd bet you still end up short of your FG number.

FYI...You cannot compare other recipes FG to yours unless the grain bills are identical. Conversion can change with the same grain bill but from different lots of malt from the same Maltser. That why they list Alpha Amylase, Diastatic Power, and other info on each bag. The maltser have it tested.

Now water and pH could be keeping you from your FG but that's a whole different post.

 

[kickz28]

Thanks LarMoeCur.

I realize unless the grain bill is the exact same, it's difficult to compare. And a lot of people in this thread are saying I'm mashing too high.

But you're telling me I should be mashing at 146-148, while I don't think I've ever seen a recipe on HBT or in any literature with a mash temp that low.

Take a look at this experiment:
http://brulosophy.com/2015/10/12/the-mash-high-vs-low-temperature-exbeeriment-results/

It's Centennial Blonde. I brewed this beer last year, so the grain bill should be the same. He did 2 mashes, one at 147 and one at 161. He got FGs of 1.005 and 1.014, respectively. When I brewed it, I mashed at 150 (like the original BierMuncher recipe) and got an FG of 1.013. That's almost as high as when Brulosophy mashed at 161!

Surely it can't be because I mashed too high?

 

[doug293cz]

Doing a 90 minute mash at 152 is the exact problem.

Beta enzymes (which make ferment-able sugars ie. maltose) work best between 131-150 F. At 149 beta enzymes start to denature at an alarming rate (roughly 5 minutes). 80% conversion happens in the first 30 minutes and only 5-10% after 30 up to 60 minutes. After that you get about 1%.

Now alpha enzymes work at 154-162 F. Alpha enzymes are the big choppers. They bust apart starches into smaller parts for the betas to covert.

It's a common misconception that alpha amylase creates only unfermentable sugars and dextrins. Alpha can create any length sugar chain, it's just much less efficient at creating mono, di and tri-saccharides (the fermentable sugars.) So, to get high fermentability with alpha amylase alone, you need long times. Beta amylase only makes maltose, and does so very efficiently. If alpha didn't create fermentables, there wouldn't be a reason for doing a mash out, and using alpha amylase in the fermenter to fix a suck fermentation (caused by low fermentability wort) wouldn't work.

So, you are mashing to high and for to long. At 30 minutes your about out of beta enzymes but your alphas are still in full force. At 60 minutes only the Terminator betas are crawling around but doing some conversation but almost nothing. Mean while your alphas are still chopping away making unfermentable sugars.

I disagree somewhat. Lower temp mashing will give higher fermentability due to beta amylase and dextrinase action. Higher temps will denature the beta amylase and dextrinase, so to get more fermentability with higher temp mashes you need to mash longer so the less efficient alpha amylase can create fermentable sugars.

Now, depending on the beer style. I would lower the mash temp to 146-148 F and mash for 60-75 minutes. I would for sure do a mash out to stop all enzymes mainly the alphas. Or you could mash at 152 F for 60 minutes and make sure you do a mash out to stop the alphas, but I'd bet you still end up short of your FG number.

Again, if alpha amylase couldn't produce fermentable sugars, why would you need to denature them with a mash out? And a mash out is really only needed if you are trying to limit the fermentability and doing fly sparging. For batch sparging, you start heating more wort sooner, which has the same effect as a mash out, so no need for a separate mash out.

Brew on

 

[OH-Brew]

I'm going to go a different route here because this sounds very similar to what I see time and time again with my beers. I almost always drop a few more points when I transfer to a secondary. My gravity can be stuck for 4 or 5 days but when I transfer to a secondary the disturbance of the wort gets things going again.

I just transferred an IPA that was sitting at 1.015 for at least 5 days (probably longer, I was on vacation) and when I transferred it into a secondary and dry hopped it, there were bubbles in the airlock the next morning. After 5 days in the secondary I was at 1.010.

I will say that I always do a starter but wouldn't be surprised if I still tend to under pitch. I don't really use the calculators but this last batch I made a 2L starter out of a smack pack but I held back some of that starter for yeast freezing.

 

[LarMoeCur]

I disagree somewhat. Lower temp mashing will give higher fermentability due to beta amylase and dextrinase action. Higher temps will denature the beta amylase and dextrinase, so to get more fermentability with higher temp mashes you need to mash longer so the less efficient alpha amylase can create fermentable sugars.

The longer you mash the more likely you will create unfermentables. Alpha amylase will create a variety of sugars (to include maltose) some are unfermentable. I just listened to a pod cast where John Palmer talked about length of mash. In a nutshell anything over 60 minutes was a waist of time. Less than 1% return. His issue in not hitting his FG and I believe if he mashed at a lower temp with more beta action over alpha his beer will finish dryer. This forum is loaded with post about mash low for dry beers mash high for sweet beers. I don't think anyone can argue that. I'd bet a donut that if you made identical beers one with a 60 minute mash and one with a 90 minute mash at the same the temp. The 90 minute mash beer would finish higher in FG and taste sweeter.

Again, if alpha amylase couldn't produce fermentable sugars, why would you need to denature them with a mash out? And a mash out is really only needed if you are trying to limit the fermentability and doing fly sparging. For batch sparging, you start heating more wort sooner, which has the same effect as a mash out, so no need for a separate mash out.

You mash out to denature the alpha amylase so it will stop producing unfermentables and less-fermentable sugars. As well as raising the temperature of the grain bed to allow better extraction of the wort. It's more for efficiency. Enzymes in the wort is a misconception. The enzymes are in the aleurone layer between the endosperm (kernel) and the husk. Which are in the grain bed not in the wort. So, heating it in the boil kettle is not stopping conversion. The grain bed is still active.

I wish alpha amylase worked the way you you describe it. I could lower my grain bill by a few pounds and save some cash by doing a longer mash.

 

[govner1]

What type of thermometer are you using to measure your mash temps. Have you calibrated it?
Second, (sorry if I missed it in the thread) do you stir your mash? How often ?

 

[doug293cz]

The longer you mash the more likely you will create unfermentables. Alpha amylase will create a variety of sugars (to include maltose) some are unfermentable. I just listened to a pod cast where John Palmer talked about length of mash. In a nutshell anything over 60 minutes was a waist of time. Less than 1% return. His issue in not hitting his FG and I believe if he mashed at a lower temp with more beta action over alpha his beer will finish dryer. This forum is loaded with post about mash low for dry beers mash high for sweet beers. I don't think anyone can argue that. I'd bet a donut that if you made identical beers one with a 60 minute mash and one with a 90 minute mash at the same the temp. The 90 minute mash beer would finish higher in FG and taste sweeter.



You mash out to denature the alpha amylase so it will stop producing unfermentables. As well as raising the temperature of the grain bed to allow better extraction of the wort. It more for efficiency.

I wish alpha amylase worked the way you you describe it. I could lower my grain bill by a few pounds and save some cash by doing a longer mash.

You got any references that say alpha amylase can turn fermentable sugar to unfermentable sugar? Both alpha amylase and beta amylase work by chopping pieces off of starch molecules and longer chain sugar molecules. Starches and long chain sugars are unfermentable. For alpha amylase to create additional unfermentables, it would have to put short chain sugars back into longer chains. I have never seen anything that says it can do this.

Everything I have ever read says a mash out is to prevent the wort from becoming too fermentable, which would result in thinner and drier beer than desired. Do you have any references to support your assertion that the opposite is true?

I agree that if OP mashed at a lower temp, he probably would have gotten a more fermentable wort. Lower temp mashes often require longer times to get compete conversion because chemical reaction rates are slower at lower temperatures.

The improved lautering due to mash out is over rated. Sugar solutions (AKA wort) only see about a 20% reduction in viscosity going from mash temp to mash out temp. You get a much bigger reduction in viscosity when the sparge water starts to dilute the wort (for fly sparging), or just mash thinner when batch sparging (equal first and second runnings volumes maximize batch sparge efficiency, and to get equal runnings you need to dilute the mash.)

Brew on

 

[arnobg]

Are you pitching from a new package of yeast each time or a slurry? Sorry if this has already been answered, but I've noticed some strains of yeast don't attenuate as well during the first pitch as they do in subsequent generations. Conan specifically is bad about this, but it applies to other strains as well.

 

[LarMoeCur]

You got any references that say alpha amylase can turn fermentable sugar to unfermentable sugar? Both alpha amylase and beta amylase work by chopping pieces off of starch molecules and longer chain sugar molecules. Starches and long chain sugars are unfermentable. For alpha amylase to create additional unfermentables, it would have to put short chain sugars back into longer chains. I have never seen anything that says it can do this.

From How to Brew. Talking about sugars in extracts but hit the nail on the Head.

"By manipulating the mash conditions, the relative percentages of sugars that are extracted from the mash can be varied. A brewer can produce a wort that is almost entirely made up of highly fermentable sugars like maltose or he can produce one that has a higher percentage of unfermentable complex carbohydrates." - John Palmer


http://howtobrew.com/book/section-1/malt-extract-and-beer-kits/gravity-vs-fermentability

"What do these two enzymes and temperatures mean to the brewer? The practical application of this knowledge allows the brewer to customize the wort in terms of its fermentability. A lower mash temperature, less than or equal to 150°F, yields a thinner bodied, drier beer. A higher mash temperature, greater than or equal to 156°F, yields a less fermentable, sweeter beer. This is where a brewer can really fine tune a wort to best produce a particular style of beer."- John Palmer

http://howtobrew.com/book/section-3/how-the-mash-works/the-starch-conversion-saccharification-rest

http://braukaiser.com/wiki/index.php?title=The_Theory_of_Mashing

I could talk for hours but typing is another thing. Read The theory of mashing it will tell you exactly how alpha and beta work together. But with out beta you are converting less-fermentables and unfermentables.

Then read this

http://braukaiser.com/wiki/index.ph...ciency_in_single_infusion_mashing&redirect=no

It shows efficiency and attenuation decrease with extended mash times.
It shows attenuation decreases with higher mash temps.

Everything I have ever read says a mash out is to prevent the wort from becoming too fermentable, which would result in thinner and drier beer than desired. Do you have any references to support your assertion that the opposite is true?

"Before the sweet wort is drained from the mash and the grain is rinsed (sparged) of the residual sugars, many brewers perform a mashout. Mashout is the term for raising the temperature of the mash to 170°F prior to lautering. This step stops all of the enzyme action (preserving your fermentable sugar profile) and makes the grainbed and wort more fluid."- John Palmer.

Perserving your fermentable sugar profile. Which means not adding less-fermentables and unfermentables.

http://howtobrew.com/book/section-3/getting-the-wort-out-lautering/aspects-of-lautering

 

[doug293cz]

...

Enzymes in the wort is a misconception. The enzymes are in the aleurone layer between the endosperm (kernel) and the husk. Which are in the grain bed not in the wort. So, heating it in the boil kettle is not stopping conversion. The grain bed is still active.

...

I see you edited and added some new content.

It matters little where the enzymes are in the raw malt grains. Saccharification is a reaction that takes place in an aqueous medium, since each action of an enzyme to cleave a saccharide chain requires a water molecule as part of the reaction. In order for a reaction to occur, you need a starch molecule surrounded by water (gelatinized), and an amylase enzyme in contact with the saccharide chain. If the enzymes didn't go into solution in the mash, the contact with the saccharide chain (in the presence of water) couldn't happen. So, yes the enzymes active in the mash are in solution.

Brew on

 

[doug293cz]

I do read extensively, and have read all of your references below. None of them support your assertion that alpha amylase can cause fermentable sugars to recombine into longer, unfermentable sugars.

From How to Brew. Talking about sugars in extracts but hit the nail on the Head.

"By manipulating the mash conditions, the relative percentages of sugars that are extracted from the mash can be varied. A brewer can produce a wort that is almost entirely made up of highly fermentable sugars like maltose or he can produce one that has a higher percentage of unfermentable complex carbohydrates." - John Palmer


http://howtobrew.com/book/section-1/malt-extract-and-beer-kits/gravity-vs-fermentability

"What do these two enzymes and temperatures mean to the brewer? The practical application of this knowledge allows the brewer to customize the wort in terms of its fermentability. A lower mash temperature, less than or equal to 150°F, yields a thinner bodied, drier beer. A higher mash temperature, greater than or equal to 156°F, yields a less fermentable, sweeter beer. This is where a brewer can really fine tune a wort to best produce a particular style of beer."- John Palmer

http://howtobrew.com/book/section-3/how-the-mash-works/the-starch-conversion-saccharification-rest

http://braukaiser.com/wiki/index.php?title=The_Theory_of_Mashing

I could talk for hours but typing is another thing. Read The theory of mashing it will tell you exactly how alpha and beta work together. But with out beta you are converting less-fermentables and unfermentables.

Then read this

http://braukaiser.com/wiki/index.ph...ciency_in_single_infusion_mashing&redirect=no

It shows efficiency and attenuation decrease with extended mash times.
It shows attenuation decreases with higher mash temps.

Nope, it doesn't. I pulled this chart from the above link. It shows fermentability (attenuation) continuing to increase with time.

"Before the sweet wort is drained from the mash and the grain is rinsed (sparged) of the residual sugars, many brewers perform a mashout. Mashout is the term for raising the temperature of the mash to 170°F prior to lautering. This step stops all of the enzyme action (preserving your fermentable sugar profile) and makes the grainbed and wort more fluid."- John Palmer.

Perserving your fermentable sugar profile. Which means not adding less-fermentables and unfermentables.

http://howtobrew.com/book/section-3/getting-the-wort-out-lautering/aspects-of-lautering

That quote from Palmer doesn't say that fermentability decreases if you don't stop enzyme activity. It says you stop enzyme activity to stop fermentability from changing. Changing can mean increasing or decreasing, as both are changes. The correct interpretation of that quote is that mash out (denaturing) is done to keep the fermentability from increasing.

Brew on

 

[kickz28]

What type of thermometer are you using to measure your mash temps. Have you calibrated it?
Second, (sorry if I missed it in the thread) do you stir your mash? How often ?

I have a Thermapen that I checked in an ice bath and in boiling water and it's accurate. I also have a Thermoworks meat thermometer that I used to double check and same temperature.

Are you pitching from a new package of yeast each time or a slurry? Sorry if this has already been answered, but I've noticed some strains of yeast don't attenuate as well during the first pitch as they do in subsequent generations. Conan specifically is bad about this, but it applies to other strains as well.

I always pitch from a new package. This is not the first time I hear about attenuation and repitching, but I always wondered if it was due to people pitching more yeast when they repitch than when they use a vial/smackpack without a starter?

 

[LarMoeCur]

I do read extensively, and have read all of your references below. None of them support your assertion that alpha amylase can cause fermentable sugars to recombine into longer, unfermentable sugars.


Nope, it doesn't. I pulled this chart from the above link. It shows fermentability (attenuation) continuing to increase with time.

View attachment 357868


That quote from Palmer doesn't say that fermentability decreases if you don't stop enzyme activity. It says you stop enzyme activity to stop fermentability from changing. Changing can mean increasing or decreasing, as both are changes. The correct interpretation of that quote is that mash out (denaturing) is done to keep the fermentability from increasing.

Brew on

First, I have a horrible habit of editing my post. My brain works faster then my fingers and after I read the post. I feel I missed important parts.

Back on topic,

Alpha enzymes can make maltos. They also produce unfermetable carbohydrates and less-fermentables sugars (more like the left overs of the chain). Can we agree on that? I've posted references from one sight and there are many more supporting what I've been saying. I'm just to lazy to look them up.

I'd like to see some references stating that alphas only produce fermentable sugars. Because that is not the case if it was everyone would mash at 156 for longer periods and let the alphas make maltos.

 

[doug293cz]

...

Alpha enzymes can make maltos. They also produce unfermetable carbohydrates and less-fermentables sugars (more like the left overs of the chain). Can we agree on that? I've posted references from one sight and there are many more supporting what I've been saying. I'm just to lazy to look them up.

I'd like to see some references stating that alphas only produce fermentable sugars. Because that is not the case if it was everyone would mash at 156 for longer periods and let the alphas make maltos.

To start, let me share one of my favorite write-ups on mashing and how enzymes work: http://braukaiser.com/wiki/index.php?title=Starch_Conversion.

I never said that alpha amylase produces only fermentable sugars, because it doesn't. What I did say is that alpha amylase cannot cause fermentable sugars to combine into longer chain, unfermentable sugars. Once a fermentable sugar is created in the wort, it never becomes unfermentable. It is possible that maltose or maltotriose, which are fermentable, could get chopped into glucose, or glucose plus maltose respectively, but the fermentability remains.

Alpha amylase is a cutting enzyme. It cuts glucose chains randomly (except near the alpha 1-6 bond branch points in amylopectin.) When cutting long chains, it creates mostly long, but shorter, chains (unfermentable), but will produce a few short chains (fermentable.) As the cutting continues, the average chain length gets shorter and shorter, and the total amount of really short (fermentable) chains increases. Taken to completion, you would be left with glucose, maltose (2x glucose), maltotriose (3x glucose), perhaps some maltotetraose (4x glucose), and limit dextrins. The limit dextrins are the original amylopectin branch points with a few glucoses on each branch.

You can still get higher fermentability in the lower mash temp ranges due to the action of limit dextrinase, which cuts the alpha 1-6 branching bonds in the amylopectin. This reduces the amount of limit dextrins in the final wort, and increases the amount of fermentable sugars. Just like beta amylose, limit dextrinase denatures rapidly at the higher mash temp ranges. Net: lower temp mashes can (not necessarily will) have lower levels of limit dextrins, and higher level of fermentables, than higher temperature mashes.

Brew on

 

[Jimbodaman]

Try mashing thinner, I'm not sure what your ratio is but I use 1.7-2.0 qt/lb when I want to go low with the FG. If I'm doing full volume BIAB (~2.9 qt/lb) I'll mash at 156 just to get an equivalent FG as mashing at 150 at 1.4 qt/lb (my usual ratio), of course adjusting mash pH.

 

[doug293cz]

Try mashing thinner, I'm not sure what your ratio is but I use 1.7-2.0 qt/lb when I want to go low with the FG. If I'm doing full volume BIAB (~2.9 qt/lb) I'll mash at 156 just to get an equivalent FG as mashing at 150 at 1.4 qt/lb (my usual ratio), of course adjusting mash pH.

Yes, thinner mashes have faster saccharification rates (ref: http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency#Mash_thickness.) So, in the same amount of time, you may get more fermentable sugars, since the alpha amylase (not much beta action in a high temp mash after the first few minutes) chops unfermentable sugars into fermentable sugars at a faster rate.

Brew on

 

[madscientist451]

Hi,



1. APA: 95% Maris Otter (Crisp), 5% Crystal 75, OG: 1.054. Mash 152F
2. Hefeweizen: 47.5% Wheat Malt, 38% Pilsner Malt, 6.5% Vienna Malt, 3% Munich malt, OG 1.054. Mash 152F

In the APA, I pitched two packets of US-05. In the Hefeweizen, I pitched one packet of WLP300, with no starter.

I feel like both batches should have finished at around 1.010. But they both finished at 1.014. I know this is not a huge problem, but I can't help but feel like they should have finished a little bit lower.


I'm not sure what else I can do or check. It seems like I'm doing everything right, yet the beer doesn't want to go down any lower.

Since you are asking what to do, here's something you might want to try: Do two re brews of the APA. Keep your method the same, except mash one at 150 and the other at 148. Also lay back a few bottles of your current APA that was mashed at 152. When the re-brews all are done, have someone pour them for you and do a blind taste test.
Forget about all the numbers for a moment and just focus on which beer suits you the best. Hopefully report back here what your findings are?
Cheers!