Found this to be interesting

[redrocker652002]

I am doing single hop beers to try and get a handle on what hops bring to the table and what flavors I like. The first one I did came back with these numbers:

OG: 1.051 FG: 1.007 ABV: 5.75 (Rounding a bit, but you get the idea)


I had been reading some stuff about crush settings, so I decided to adjust my mill to the finest I could get. Now, this beers number, same kit, but different hops are as follows:

OG 1.057 FG: 1.004 ABV 6.75 (Rounding a bit, but you get the idea again LOL)

According to the sheet that came in the kit, my OG should have been between 1.049 and 1.054 and my ABV should have been in the low 5%.

So, I am looking at a change of about .006 on my OG and a drop of about .003 on my FG. ABV is about 1.5% higher on the second.

This seems very strange as I used the same yeast and it sat in the same spot on both. The temp on the second one might have hit 72 to 73 at some points, so maybe it fermented a bit warmer, but other than that, all was exactly the same with only the grain mill adjustment being changed.

Would adjusting the crush of the grain make such a big swing in OG as well as FG? Or am I just reading way too much into something that just doesn't matter? LOL. I am good at that too. I am happy if I got more out of the grain if that is the case, but just making sure. I checked the numbers twice on both recipes to make sure I was on, and I was. Any input?

 

[hotbeer]

The simple answer is that when you crush your grain finer, you should expect to get more out of your malts. Though some mash methods get a lot from coarser crush than other mash methods.

You have to know what OG you'll get per amount of malts you use based on your experience with your equipment and processes. Then you can adjust the recipe amounts to match.

So if you are following a recipe and want your beer to be the same beer as the recipe, then you adjust the amount of fermentable malts and other stuff to achieve that OG. And you pick a yeast that is going to give you the attenuation that will give you that FG. Though your mash temps will affect what ratio of fermentable sugar to unfermentable sugars you will have. So that complicates the FG thing.

Recipes for beer, just like recipes for other food depend a lot on the person making it as to whether it's any good or not. They aren't quite exact scientific formulas because there are so many processes that every one of us do differently.

How different did the two beers taste? Your FG being off by 0.003 suggests to me that your mash temps were probably not held to the same profile. Or that one had a brief but large excursion from the desired temp. Most yeast I've seen can attenuate that OG to a more normal 1.010 or less and even the ABV isn't outside their alcohol tolerance.

But your batches seem to have gotten more attenuation than I'd expect. Were they possibly infected by something. From your OG given as 1.057 and greater than 6.7 ABV, that'd be a FG less than 1.006. Which for what I've brewed, I'd wonder about wild stuff getting in if they were lower than 1.008. Usually ales for me are a FG 1.008 - 1.012, depending on the recipe.

But there probably are other reasons too. Still, those aren't really big differences that I'd worry about for homebrew. Unless you are planning on going to competitions with it.

ABV isn't really a useful value to me. I'd rather have seen the FG for each. Never mind, I figured out finally that what you listed as SG is what you must mean to be OG. SG can also be your FG or any Specific Gravity reading between, before or after.

 

[redrocker652002]

The simple answer is that when you crush your grain finer, you should expect to get more out of your malts. Though some mash methods get a lot from coarser crush than other mash methods.

You have to know what OG you'll get per amount of malts you use based on your experience with your equipment and processes. Then you can adjust the recipe amounts to match.

So if you are following a recipe and want your beer to be the same beer as the recipe, then you adjust the amount of fermentable malts and other stuff to achieve that OG. And you pick a yeast that is going to give you the attenuation that will give you that FG. Though your mash temps will affect what ratio of fermentable sugar to unfermentable sugars you will have. So that complicates the FG thing.

Recipes for beer, just like recipes for other food depend a lot on the person making it as to whether it's any good or not. They aren't quite exact scientific formulas because there are so many processes that every one of us do differently.

How different did the two beers taste? Your FG being off by 0.003 suggests to me that your mash temps were probably not held to the same profile. Or that one had a brief but large excursion from the desired temp. Most yeast I've seen can attenuate that OG to a more normal 1.010 or less and even the ABV isn't outside their alcohol tolerance.

But your batches seem to have gotten more attenuation than I'd expect. Were they possibly infected by something. From your OG given as 1.057 and greater than 6.7 ABV, that'd be a FG less than 1.006. Which for what I've brewed, I'd wonder about wild stuff getting in if they were lower than 1.008. Usually ales for me are a FG 1.008 - 1.012, depending on the recipe.

But there probably are other reasons too. Still, those aren't really big differences that I'd worry about for homebrew. Unless you are planning on going to competitions with it.

ABV isn't really a useful value to me. I'd rather have seen the FG for each. Never mind, I figured out finally that what you listed as SG is what you must mean to be OG. SG can also be your FG or any Specific Gravity reading between, before or after.

sorry, the SG should have read OG. Not sure why I typed that other than that is how the recipe referred to it. LOL. Other than a slight temp jump on the second batch, maybe 5 degrees for less than 10 minutes, everything went pretty much the same. I have not tasted the other, and I ran my keg dry of the first recipe, but I have one more with slightly different hops to brew, so I might try that and see if I get the same numbers again. Either way, I tasted it when I measured final gravity and it did not taste off to me. But, I am not a really good expert taster, so maybe it got something in it. I don't know. Anybody near South San Francisco wanna come by in a couple of weeks and give me an opinion? I have regular store bought beer if it turns out bad. LOL. Anyway, thank you for your input, I appreciate any and all.

 

[hottpeper13]

I've found that the mash time matters more then the temp to a degree(pun intended),when it comes to FG. If I want a dry beer I mash for 2 hours or overnite.

 

[DBhomebrew]

I've found that the mash time matters more then the temp to a degree(pun intended),when it comes to FG. If I want a dry beer I mash for 2 hours or overnite.

Agreed.

A big reduction in grain crush size will extend the mash time for the molecules of starch that had been living at the center of those larger bits. If with a larger crush it takes 15m for the most internal starch to gelatinize, a flour-like crush would be near immediate. In this hypothetical example and a 60m mash, some of the starch in the large crush will really have a 45m mash. The flour-like crush will provide a full 60m to all the starch.

Note, no actual data has been harmed in the writing of this theoretical example.

 

[doug293cz]

Agreed.

A big reduction in grain crush size will extend the mash time for the molecules of starch that had been living at the center of those larger bits. If with a larger crush it takes 15m for the most internal starch to gelatinize, a flour-like crush would be near immediate. In this hypothetical example and a 60m mash, some of the starch in the large crush will really have a 45m mash. The flour-like crush will provide a full 60m to all the starch.

Note, no actual data has been harmed in the writing of this theoretical example.

I think you have the time effect correct, but the timing is off. Low conversion efficiency with coarse crushes indicates that gelatinization is not complete even after an hour sometimes. Gelatinized starch very quickly goes into solution as alpha amylase chops the insoluble starch chains into shorter, soluble chunks. Once all starch is dissolved, the SG of the wort stops increasing, but the fermentability continues to increase, as the enzymes do more chopping of the dissolved starches and unfermentable sugars. 100% conversion is reached before maximum fermentabilty is reached. If the SG is lower than what would be achieved at 100% conversion, that means there is ungelatinized starch remaining.

Also, fermentability depends a great deal on how much starch has been dissolved before all of the Limit Dextrinase enzyme has been denatured. Limit dextrinase reduces the amount of dextrin (unfermentable sugar) that remains in the final wort. Limit dextrinase denatures faster than beta amylase, so remains active longer at lower mash temperatures. A finer crush gelatinizes faster, making more soluble starch available earlier during the mash, which means less dextrins in the wort, and greater fermentablity.

Brew on

 

[Bassman2003]

For the record, Limit Dextrinase is most active at 144F.

 

[redrocker652002]

Wow, great info being shared. I like it, and here I thought it was kinda a stupid question. LOL

 

[doug293cz]

For the record, Limit Dextrinase is most active at 144F.

Something to know about peak activity temperatures is that they represent the temperature where the enzyme can get the most work done before it gets denatured. It works faster at higher temperatures, but denatures even faster, so less total dextrin gets hydrolyzed at higher temperatures. So, you still get significant limit dextrinase action at higher mash temps than 144°F. (The same effect applies to all the other enzymes active in a mash.)

Do you have a link to the research that established this temperature? Peak activity temperatures are highly dependent on the actual test conditions, which may not correspond to the conditions in a typical mash.

Brew on

 

[Bassman2003]

Good points. I was just trying to give some perspective on a good way to increase LD and fermentability. My wording could have been better!

There was a paper listed here a few months back (you provided the PDF) which compared different mash temps and variables for LD effectiveness. What I took away was a rest in the 144F range yielded the best balance of duration and effectiveness. As always, other factors are involved but to be honest, these conversations can get too technical at times to be real-world useful for a lot of homebrewers. So I (maybe wrongly) generalize for common practice considerations.

Here is the thread:

https://www.homebrewtalk.com/threads/mash-temperature-vs-mash-time.727176/

 

[doug293cz]

Good points. I was just trying to give some perspective on a good way to increase LD and fermentability. My wording could have been better!

There was a paper listed here a few months back (you provided the PDF) which compared different mash temps and variables for LD effectiveness. What I took away was a rest in the 144F range yielded the best balance of duration and effectiveness. As always, other factors are involved but to be honest, these conversations can get too technical at times to be real-world useful for a lot of homebrewers. So I (maybe wrongly) generalize for common practice considerations.

Here is the thread:

https://www.homebrewtalk.com/threads/mash-temperature-vs-mash-time.727176/

I think I know the paper you are referencing. I need to go back and reread it.

Yes, the details of what goes on when brewing can get very complicated. But, it is not necessary for brewers to understand all of the science in order to make good, or even great beer. I present information for those who might be interested in a better understanding, and try to explain things using language that is more understandable to non-scientists/engineers. Hopefully, I succeed more than I fail. Generalizations are acceptable, as long as they don't contain misinformation.

Brew on

 

[Bassman2003]

I agree and you are great resource to this forum. Fermentability and attenuation are two things I try to focus on as imho, these separate mediocre, good and great beers. Limit Dextrinase seems like an important part of this pursuit.

 

[redrocker652002]

I think I know the paper you are referencing. I need to go back and reread it.

Yes, the details of what goes on when brewing can get very complicated. But, it is not necessary for brewers to understand all of the science in order to make good, or even great beer. I present information for those who might be interested in a better understanding, and try to explain things using language that is more understandable to non-scientists/engineers. Hopefully, I succeed more than I fail. Generalizations are acceptable, as long as they don't contain misinformation.

Brew on

I appreciate the info, while some goes over my head, some is really cool to know. I am not a science guy but this is very interesting to me. I found that, at least in the last batch, the finer crush gave me a higher SG. Will that happen again? Who knows, but I am going to keep notes to see. To understand why it did that is cool. Will I be able to quote it? Ummmm, probably not LOL. Either way, the fact that you took the time to write it up is great, and I appreciate it. Rock On!!!!!!