Topics

46

Zymurgy / 2010 M/A Geeks column - Malt Conditioning

« on: March 26, 2010, 07:32:52 AM »

Let me continue this with providing a place to discuss malt conditioning. I know we have discussed this many times. But maybe there are still some lingering questions about this.

Kai

47

All Grain Brewing / Creation of larger sugars and dextrines from small sugars during mashing

« on: March 25, 2010, 08:26:51 PM »

I just came across something that goes against what we have been told so far about starch conversion in mashing. It seems obvious that glucose chains are only split during mashing and that over time the length of the glucose chains goes down. Narziss and Back mention in Technologie der Würzebereitung that malt does contain transferase enzymes which can fuse glucose and maltose to form dextrins. Now the effect is not dramatic and doesn't really affect our simple model of mashing. But they mention it as one of the reasons why resting the main mash at 145 F for an extended time during a decoction does not affect the fermentability significantly. The other reason is the already diminished b-amylase activity.

I thought that wa interesting. I'll have to see if I can find a reference in English.

Kai

48

General Homebrew Discussion / When is it cheating?

« on: March 21, 2010, 08:33:30 PM »

The "souring fermentation" thread (http://www.homebrewersassociation.org/forum/index.php?topic=1718.msg20739;topicseen#msg20739) got me thinking: When is it an acceptable shortcut when when is it cheating?

I assume that everybody will agree that adding lactic acid to sour a beer to taste might be cheating. But what about starting a lactic only fermentation and add the result to the beer to taste? Isn't that also a shortcut that allows you to control the sourness w/o having to control the actual fermentation? Or adding acid malt to the mash which allows you to make a sour beer w/o having to deal with the bugs otherwise needed for that.

How different is this from using specialty malts instead of going through a decoction mash to get the same flavor. And to take it even further, how about adding pure alcohol to a moderately yet high FG beer to create a high alcohol beer w/o having to deal with the fermentation complications of such a beer?

Are there any rules to brewing that would disqualify a Berliner Weisse which was simply a low gravity neutral wheat beer that had lactic acid added?

I think these are interesting questions worth pondering. Beyond the Reinheitsgebot: Where is the line and who decides what's ok and what not.

Kai

49

Kegging and Bottling / How much effect does repeated foaming have on head retention?

« on: March 19, 2010, 08:59:55 PM »

Inspired by a recent discussion about foaming and head retention I conducted a simple experiment where I shook up one beer sample repeatedly while the other was shaken only once. That one time shaking was necessary to make the experiment simpler.

In the end I was not able to detect any significant difference in head retention between both samples. I don't think that it is a myth that foaming affects head retention, I just think that its impact is too small to be noticed by this experiment.

Here is the write-up with pictures: How much effect does repeated foaming have on head retention?

Kai

50

Ingredients / Alkalinity reduction using lime

« on: March 18, 2010, 07:05:56 AM »

I have been busy over the last few weeks writing another article for braukaiser.com. This time about reducing water alkalinity by using slacked lime, which is a commonly used procedure in large scale brewing but rarely used by home brewers. Though I doubt that I’ll convince many of you to give it a try since it doesn’t work for types of high alkalinity water and it takes more preparation that dilution, building from RO water or addition of salts it is a very elegant way of treating brewing water.

This article grew rather large. As I was writing it I found a lot of information about the subject that I just had to mention as well.

Enjoy: Alkalinity reduction with lime

Kai

51

All Grain Brewing / predicting mash pH from beer color and residual alkalinity.

« on: February 26, 2010, 11:18:59 AM »

For a while now I have been thinking how to best estimate mash pH or necessary residual alkalinity from beer color, some grist information and mash thickness. I know John Palmer has this in his water spreadsheet and it is a very popular feature.

I like the idea of giving brewers guidance on what water residual alkalinity to shoot for based on a simple beer parameter like color. It makes sense since mash pH and beer color is largely affected by the color of the grains that are used to brew the beer. Using the data from my mash pH experiments I found that it also matters how much of the color comes from roasted malts and how much comes from crystal or base malts. So I knew that I would need a way to incorporate that somehow into a SRM -> mash pH formula. I also noticed that mash thickness can have a strong impact on mash pH, especially when the residual alkalinity is fairly far away from zero. So I decided to look for a formula that can provide a reasonable accurate mash pH prediction based on beer color, percentage of roasted malt, mash thickness and residual alkalinity.

How I found that formula is described here: http://braukaiser.com/wiki/index.php?title=Beer_color%2C_alkalinity_and_mash_pH which is not so much intended for a broad audience of home brewers. It should be seen as a documentation for interested brewers on how the formula or algorithm was developed which is implemented in my water calculation spread sheet (http://braukaiser.com/documents/Kaiser_water_calculator.xls). At the end it also shows 2 tables that can be used to determine the range of water residual alkalinity that works well for a given beer color, mash thickness and roasted malt percentage.

After having all that I’m curious how well the estimation matches actual data that brewers have seen in home brewing. I rarely calculate beer color for my beers but plan to go back through my records and find a few representative examples.

Kai

52

Yeast and Fermentation / White Labs trial fermentation data

« on: February 18, 2010, 07:46:13 AM »

Running my own yeast bank usually keeps me away from White Labs and Wyeast's web sites but I'm glad I just checked out White Labs.

They recently added data from standardized mini fermentation for some of their strains. This is pretty cool. However, they don't list the limit of attenuation of the wort that was used for the tests. I have to ask them about this.

Kai

53

Yeast and Fermentation / Kraeusen removal, what difference does it make

« on: February 13, 2010, 10:21:47 PM »

Based on the discussion we had here: http://www.homebrewersassociation.org/forum/index.php?topic=486.0

I made an experiment where I brewed my Altbier with and w/o removal of the bitter Kraeusen gunk. To me the result is clear: I'll stick to Kraeusen removal for all beers since the one where the Kraeusen fell back has a very unpleasant finish for me.

Here is a write-up: Should the Kraeusen fall back into the beer?

Kai

54

All Grain Brewing / Chris Colby on malt conditioning

« on: February 09, 2010, 02:20:20 PM »

I just listened to Chris Colby’s BBR interview about malt conditioning and his techniques for conditioning malt seem much more complicated than the spay and mix process that I proposed? Steaming in the mash tun or using a partner to sprinkle the malt with hot water? Is he just trying to avoid my technique? BTW, if you pour water over the malt you will get it too wet and gum up the rollers. I’ve tried that first.

James referenced my work but Chris didn’t I doubt that he hasn’t come across malt conditioning when searching the web.

I haven’t come up with this but like to get some credit for bringing it up to the home brewers attention here in the US.

(http://media.libsyn.com/media/basicbrewing/bbr02-04-10condition.mp3)

Kai

55

Equipment and Software / I finally got myself a refractometer ....

« on: February 02, 2010, 02:17:07 PM »

…. and have been busy on reading up on how they work. Pretty clever I must say. The ATC function, for example, is simply done by placing the scale on a bi-metal strip. This shifts the scale up and down based on the temperature of the refractometer itself.

The measurement of refractive index is based on “total internal reflection”. Depending on the refractive index of the test solution you are either looking at the blue background of the prism (total internal reflection) or through the sample and lid at the light source. The refractive index changes at what angles that happens and that’s why you are seeing a transition from white to blue. That also allows a very simple design.
Kai

56

Ingredients / Fivestar's 5.2 mash buffer

« on: January 28, 2010, 01:01:41 PM »

Does anyone have the official instructions/data sheet for that product. I went to their web site but there is very little information. I remember that more of the links on their web-site used to work.


Kai

57

All Grain Brewing / malt crushing and wort polyphenols

« on: January 26, 2010, 08:35:40 AM »

Over the past few days I have been reading most of what I can read from Narziss and Back’s Technologie der Wuerzebereitung on Google Books and the amount data given in that book is just amazing.

Here is something I’d like to share:


(source: http://books.google.de/books?id=rlcwl7aS8KYC&printsec=frontcover&dq=technologie+der+w%C3%BCrzebereitung&cd=2#v=onepage&q=&f=false)

It shows the polyphenol concentration of the cast out wort in mg/l (top row) as a function of the way the malt was crushed. The top header is: mash filter (pulverized grist), lautertun crushed dry, lautertun crushed conditioned and wet crushed. As you can see, in this case conditioned malt left 13% less polyhenols in the cast out wort.

While there seems to be a difference in the wort analytics this does not show if there will be a difference in taste. polyphenols are not necessarily and in some other section they of this book they are also considered as contributors to the body of the beer.

I hope I didn’t scare anyone into conditioning their malt now. I just thought that this was an interesting data point which I haven’t seen before.

Kai

58

Questions about the forum? / Things I don't like about the Recent message lists

« on: January 17, 2010, 07:04:42 AM »

One thing that bothers me with the list of threads that I have replied in and have new messages or that have new messages in general is that a thread will get off that list as soon as I look at it. Oftentimes I take a peek and want to answer later. But then I have to search for that particular thread.

Anybody having the same problem or a solution?

Kai

59

Yeast and Fermentation / stuff I'm finding under the microscope

« on: January 12, 2010, 08:39:15 AM »

Now that I have a microscope I look at my yeast and beer samples quite often and I’m shocked at the amount of non yeast bugs that I’m seeing . Occasionally I see rods (likely lacto bacillus) and just yesterday I found a surprisingly high number of larger bacteria in my Doppelbock. Those have irregular shapes, are about twice the size of yeast and I was able to make out the flagellum (tail or tentacle like protrusion). Kinda scary to see that in my beer.

But before the microscope I didn’t even know that they were there. The beers don’t taste infected and the pH is around 4.4 which is typical. So I’m not freaking out about this but I used to consider my sanitation processes top notch. For now I’m going to pay closer attention to when non yeast bugs starts to appear in samples. I also started doing wort stability tests again and when I looked at the assortment of bugs in them it was almost all. hardly any rods or other contaminants.

I have to find a low cost way of taking pictures with the microscope to share them. Does anyone know of a good on-line or other source for identifying beer and wort spoilers by looking at them?

Kai

60

All Grain Brewing / In case you wonder about differences in efficiency calculations

« on: January 11, 2010, 01:20:22 PM »

Here is something that I wanted to write about for a while: the differences between the 2 different types of efficiency calculation that are in use by brewers.

I use the Plato based one in all my spreadsheets while most other home brewers use the gravity point and ppg based one. While I found that there is much less difference than I initially expected it is an interesting exercise in using the Plato definition and its relationship to the specific gravity. It also shows how the ppg values for sugar and malt can be derived from their respective extract potential given in %. It's pretty math heavy though. Nothing really bad but a lot of different variables that need to be tracked.

Differences in Efficiency Calculations

Conclusions

Does it really matter in brewing whether you use the ppg based forumla or the Plato based one? Not really. If you always use the same formula for efficiency calculation and subsequent recipe design it doesn't matter at all. It may matter when discussing and comparing efficiency with other brewers. In this case the ppg based approach is within 1% of the actual efficiency for all realistic gravities. That error, however, is too small to be a conern in home brewing. Using the % based efficiency calculation with a crude sg to Plato conversion, on the other hand, can overestimate efficiency significantly. Thus care needs to be taken when converting Plato or Brix readings into specific gravity readings. That is in particular true for high gravity worts.

Kai