I decided to give the blog a face lift and go with a simpler looking theme. I’ll have to spend some additional time to restore the links I list. Switching back to the old theme didn’t restore them either.

Hop Juice

Could there be something stronger than the IPA (or KaIPA for this matter) itself?

Yes, the beer that can be squeezed from the spent dry hops. Something only a true brewing geek knows to enjoy. Besides being murky like the Ganges in the rainy season, the aroma is pronounced but not overpowering. The bitterness, however is much harsher than the actual beer. It particularily lingers in the back of the throat, which I don’t appreciate too much.


What happened?

Some of you may have wondered what happened to braukaiser.com between April 1st and April 6th. Well, I forgot to check the e-mail account associated with that domain and let my domain name expire. After the initial shock, which included the fear that I lost my rights to that name, I realized that it was simply a matter of paying the renewal fee and getting braukaiser.com to point to my hosting account again.

Everything should be running just fine again and I can also receive e-mails from my braukaiser.com account. This certainly taught me a lesson about staying on top of these administrative tasks.

Brewing water spreadsheet update

I decided to give my brewing water calculator a face lift and also add some new features that brewers were looking for. The face lift happened mostly on the “basic” page, which is now more intuitively grouped into the sections for

  • base water
  • mash and grist info
  • salts and acids
  • resulting water profile and mash pH prediction

These are other things I changed or added:

  • changed the treatment of undissolved chalk such that it only contributes half its calcium since it contributes only half its alkalinity. Chalk’s solubility in mash seems to be limited and what does not dissolve and contribute to a rise in alkalinity should not contribute calcium ions either.
  • salt additions can now be made in g and mg/l. You can select the unit
  • the salts to be added can be reported in g and tsp. The latter is useful if your scale breaks down or you don’t own one yet.
  • lactic acid and phosphoric acid are supported. Are there many brewers who are actually using hydrochloric or sulfuric acid? I may add support for those later.
  • water boiling for alkalinity reduction has been added to the “advanced page”. This was easy to add since I already supported lime treatment
  • pH shift estimation for the major water treatment steps
  • salts can be added to all the water or strike water only. If they are only added to the strike water, the resulting water profile for the strike water or the overall water can be reported.

But a number of features remained the same:

  • The basic and advanced pages are still there. Anything entered in the basic page will automatically carry over into the advanced page. The idea is to support a wide variety of users.
  • the tall and narrow formatting remained in order to better support its use on mobile devices
  • I avoided macros or the use of fancy functionality in hope that this spreadsheet can be supported by mobile devices
  • the SRM based mash pH prediction is still there. Compared to some tests I’m running with grist based mash pH prediction, it does surprisingly well and is actually more accurate in most cases.
  • support for SI and US units. Under the hood it uses SI units almost exclusively. There is a spreadsheet version that is preloaded with US units even though this changes only 2 fields.

The new Kaiser_water_calculator.xls can be found in the Ingredients section on my site.

If you find bugs or have suggestions for improvements let me know here or send e-mail to “kai at braukaiser dot com”.

Basic Brewing Radio on mash conversion and iodine test

I had the honor to join James, Chris Colby and Zot O’Conner in a Basic Brewing Radio show that discussed the results of a listener experiment on mash conversion time.

Triggered by Chris Colby’s comment that mashes convert in as little as 10-15 a listener experiment was conducted for which listeners had to record the progression of the iodine test and, if possible, the sweet wort extract content in the mash.

The result is what I have been observing on my own batches and in experiments: a negative iodine test (no starch or large dextrins present) is not necessarily an indication that the mash is done. Even after a negative iodine test the extract content in the sweet wort keeps increasing which is an indication that there is continued release of sugars and dextrins into the wort. If the wort would be lautered too early the efficiency into the kettle might suffer.

The experiment was also a good insight into how different brewers conduct the iodine test. Most are using the iodine solution in undiluted form which makes it difficult to tell if the color is coming from a reaction with starch or large dextrins or is coming from the iodine itself. I recommend diluting the iodine solution with rubbing alcohol (1 part iodine solution like iodophor, Lugol’s iodine or providone iodine and 9 parts rubbing alcohol).

Basic Brewing Radio: March 3, 2011 – BYO-BBR Conversion Experiment (iTunes|Streaming mp3)

About pH Targets and Temperature

I noticed that the topic “At what temperature should mash pH be measured” comes up once in a while.  Just recently I had an e-mail and an on-line discussion with a fellow home brewers on the same subject.

Fact is that the pH of a solution changes with temperature. It is caused by a change of the dissociation constants of the various acids/bases that are in the solution. Even water is considered an acid since it can donate hydrogen ions, although in most cases it is not dominating pH at all. The extent of the change depends on the substance. By the same mechanism even the pH optimum of enzymes may shift with temperature it is also dependent on the ionization state of the acids in the protein. I believe that the 0.35 correction factor for mash temp (65 C) vs. room temp (25 C) pH contains both the aspect that the actual pH in the mash is lower at 65 C compared to 25 C and that the pH optimum of the amylase enzymes shifts a bit from the value that can be observed by room temperature mashing.

But none of this matters since by convention pH values in brewing are reported as the pH of a room temperature sample. This arises from the laboratory practice of cooling pH samples before pH is tested. While pH meters can correct for temperature and their probes may be able to withstand higher sample temperatures, testing only cooled sample extends the life of the probe. This common practice also means that reported pH optima and pH ranges are for room temperature samples even though the actual reaction happens at higher temperatures. A.J. deLange mentioned to me the “by convention” aspect which is an important argument in this discussion. “By convention” means that we could do it differently but we settled on this particular method in order to communicate our observations and recommendations more clearly.  Just as an example, another brewing measurement where we have a convention is the expressing the extract content in specific gravity. Rather than Plato, which measures the extract content by weight and which is something that doesn’t change with temperature, specific gravity does change with temperature and we assume that all those measurements are corrected for temperature such that they apply to a 68 F sample. The practice is and should be done for pH measurements. To be exact you’ll have to cool hot samples and warm cold (e.g. beer) samples.

It’s also helpful to take into account how we arrived at these pH optima/ranges. They are determined by conducting a series of mashes (at correct mash temp for that enzyme) with differing pH. The pH is tested in a room temp sample. The amount of product produced during these reactions (sugar, for example) is then plotted over this room temperature pH.

The same is true with boil pH recommendations where kettle boils at different pH values were done to determine how wort quality changes when the boil pH changes.

One problem is that hardly any author is explicit about this. I assume that most of them see it as a given that they talk about pH from room temperature samples. Briggs was the only one I found that made a distinction. This lack of explicitness, if this is a word, seems to cause a lot of confusion with home brewers.

As for the origin of this confusion, I believe that early home brewing literature and publications are to blame. John Palmer’s 1st edition of “How to Brew” states this:
“When you mash 100% base malt grist with distilled water, you will usually get a mash pH between 5.7-5.8. (Remember, the target is 5.1-5.5 pH.)”

In this sentence he mixes room temp and mash temp pH values. The 5.7-5.8 base malt pH is correct when seen as the pH of a room temperature mash sample while the 5.1-5.5 pH target is only correct when seen as a mash temp pH target with a conversion factor of 0.35. With the correction the room temp sample pH target range is 5.45 – 5.85, which is more correct.

The pH optima that John cites for various enzymes seem to be mash temp pH values. He doesn’t quote a source but the only source that I found which lists mash temp pH values is Briggs’s Brewing Practice and Science book. In this he also gives room temp pH numbers.

I came across this inconsistency when I started reading more technical brewing literature. The pH optima listed for the enzymes for the given optimal mash pH ranges just didn’t line up with what I heard from other brewers. It took me a while and doing my own pH vs. conversion experiments to get a clearer picture of this topic.

And to answer the question that is most interesting to brewers, I believe that the optimal mash pH range is 5.3-5.5 for light beers and 5.4-5.6 for darker beers when testing a room temperature sample of the mash. This pH range is a good compromise between optimal enzyme activity, good boil pH and good cast-out wort pH.

New article about mash pH contol

I finally completed a new article that took almost a year to write. It took so long not only because I took a break from brewing and writing about it for a while, but most importantly I wanted to write an article that is well supported by brewing experiments and close observations of mash pH in batches of beer that I brewed over the last year. All too often get brewers caught up in the theoretical aspect of water and mash chemistry with the aim to calculate everything with the best precision possible. But what is commonly overlooked is that measurements are not precise enough to require this precision and, what is mots important, malt’s reaction to pH changes is not that predictable anyway. To capture that aspect experiments are necessary.

The objective of this article was to give the advanced brewer an insight in the major factors that affect mash pH and how it can be corrected. Based on experiments it also gives guidelines that allow the estimation of mash pH changes based on the water profile, water treatment additions or mash additions, without focusing too much on this aspect. Those are largely based on mash pH experiments I conducted including the data published in The effect of brewing water and grist composition on the pH of the mash.

With this article I also released a updated version of my water calculator. But more on this later.

Click here: Mash pH control


Moved to new location and blog engine

After struggling with too many spam comments and somewhat limited spam control support from Lifetype I finally made the move to WordPress. Since I moved the old blog posts by importing the RSS feed, the few good comments I had are gone. Sorry about that.

Links to the posts will also appear in a more readable format, which is nice.