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Ingredients / Lactate Taste Threshold Experiment
« on: March 11, 2013, 03:41:41 PM »
Last weekend I did a yeast handling presentation to Brew Free Or Die club members and I took the opportunity to conduct a lactate taste threshold experiment with 8 club members. While it had little to do with the topic of the technical session it is a subject where I wanted to do some experimentation for quite some time.

Acidulated malt and 88% lactic acid are very popular acids for mash pH correction but since lactic acid has a rather distinct taste the question that is on many brewer’s minds is: “How much lactic acid is too much“.

Since in most cases lactic acid is only added to counteract water alkalinity and bring the mash pH into the desirable range of 5.3-5.5 it can be assumed that the added lactic acid will not lead to a lower than normal beer pH. In other words, we don’t have to worry about beers that taste sour.  But we do have to worry about the characteristic taste of lactate. Lactate is what’s left when lactic acid gives up its proton to neutralize a base or contribute to pH changes.

The experiment was designed such that the acidity of the lactic acid was neutralized with slaked lime. While that also adds calcium in addition to the lactate it matches brewing reality where highly alkaline waters oftentimes come with high calcium levels. I had the choice between calcium (from slaked lime) or sodium (from sodium hydroxide).  Both calcium lactate and sodium lactate tasted very similar in water which shows that sodium doesn’t necessarily lead to a salty taste. I decided to go with calcium lactate since calcium is generally the dominant cation in alkaline waters.

I was very surprised to see how many of the tasters struggled with identifying the flavor in the 4 sets of samples they were given (water, Bud Light, Budweiser and Sierra Nevada Torpedo Ale). Even levels as high 1200 mg/l, which amounts to a whopping 23% acidulated malt, were not correctly identified by some tasters.  Below is a link to a more formal write-up of the experiment and those interested can go ahead and check my numbers.

Here is a chart that shows for each taster the highest lactate level that was identified as tasting like the control:

After having done this experiment and having tasted samples with added lactate myself I think that a safe upper limit of 400 mg/l lactate or 7% acidulated malt is reasonable with the assumption that the mash and beer pH are at acceptable levels. While 7% is higher than the 5% that is currently seen as the safe upper limit for acidulated malt use it should be noted that there might be other benefits to  reducing the amount of minerals in a given water before acidulated malt is used to neutralize the remaining alkalinity.

A formal write-up of the experiment can be found on the wiki: Lactate Taste Threshold Experiment

When I started helping Brewer’s Friend as a technical adviser I couldn’t help but notice that the mash pH predicted by its brewing water calculator was way off. Since I have done extensive work on brewing water and mash chemistry already I took this as an opportunity to develop a new Mash Chemistry and Brewing Water Calculator from scratch. The goal was to build something that provides a simple and intuitive user interface yet implements the underlying chemistry to at a level of accuracy that is generally not done in brewing water calculators. In fact the only calculator that goes to that extent is A.J deLange’s NUBWS (Nearly Universal Brewing Water Spreadsheet).

Since Brewer’s Friend is an online recipe calculator the new calculator would also become an online tool. This worked very well in its favor since it is very cumbersome to model complex systems in spreadsheets. PHP, or any other programming language for that matter, makes that type of modeling much easier. In addition to that modern web browser technology makes it simple to create dynamic forms that can readily adjust the form to only asking the user for information that is actually needed based on the context.

That was 3 months ago and after many long nights of coding, re-coding, testing and even running more mash pH experiments version 1.0 has finally been released and is available on Brewer’s Friend.

When you first open the calculator it presents itself like any other basic water with sections for source water, salt additions, grist, mash pH and final water report following this flow chart:

Flow chart for basic use of the calculator
But that’s not all. For those who need want to do more complex water treatment calculations, the full flow chart looks more like this:

The first release features makes these features available:

  • Blending of two water sources
  • Bicarbonate/carbonate content can be set from either alkalinity or bicarbonate. pH can also be entered for increased accuracy
  • Electrical balance (ion balance) of the source water
  • Simple GH&KH measurements can be used as a crude way of specifying the source water.
  • Report of basic and advanced water parameters of the source water. Among the advanced properties are temporary/permanent hardness and CO2 partial pressure
  • supports all major salts (including magnesium chloride) as well as the hydroxides slaked lime and lye
  • Alkalinity reduction through boiling and slaked lime. These are features that rely on a more accurate implementation of the water’s carbo system
  • Wide range of supported acids including the less commonly used citric, tartaric and acetic acid.
  • Salt and acid additions can be made to all water or only the strike (mash) water
  • A different water source can be used for sparge water. In most cases that might be reverse osmosis water when the tap water is suitable for mashing.
  • Salt additions to sparge water or kettle
  • Sparge water acidification with a wide range of acids.
  • Detailed report of the treated mash water
  • Support for undissolved chalk.
  • Grist pH properties can be estimated from beer color or malt bill
  • Mash pH prediction based on balancing the various weak and strong acid systems that might be present (carbo system, weak acids and grist)
  • overall water report based on the mash and sparge water profile
  • target water comparison of the overall water report

For now this tool is only available as a stand-alone calculator but Brewer’s Friend is planning to integrate it into the recipe editor. This will eliminate duplicate entry of the beer’s malt bill. It will also allow the user to use saved source water profile(s).

Go ahead and give it a try. If you have feedback, positive or negative, please let me know:

In subsequent posts I’m planning to write more about some of the discoveries I made while writing this tool and how it’s mash pH prediction does compared to actual mash pH data that I have.

General Homebrew Discussion / White Labs Alcohol Test Kit
« on: December 06, 2012, 07:05:43 PM »
I've noticed that White Labs is also marketing their lab tests to home brewers. But how valuable do you think they are?

$36 to have alcohol tested is pretty low value in my opinion. Alcohol is fairly well determined by OG and FG readings and we don't need an exact value anyway. Maybe useful for bragging rights if you were going for a high alcohol brew.

IBU measurements might be useful for bragging rights and diacetyl and bacteria for getting to the bottom of a persistent issue. But all these tests are rather expensive for the common home brewing budget.


Last night I joined my Boss at DejaBrew, an on-premise brewing place in Shrewsbury MA, to watch him and his friends brew a few batches of beer. Like many on-premise brewing places the brewing process is largely extract with specialty grains.

First thing I noticed is that even starchy grains like Aromatic and Rauchmalz get "steeped" in the full water volume while the water heats to 180F. No "proper" mash here but the beers don't seem to suffer from starch haze either. Looks like that even at the high water to grain ratio, that exist, the starches that make it into the water convert just fine.

They also pitch a single WL vial into 10 gal of cooled wort, even for lagers. The ales tasted fine and were enjoyable. The lagers were ok too, but did lack some of the flavors that I like in them. But none of the beers had off flavors that we commonly associate with under pitching.

Wort is aerated by shaking the heck out of the fermenters, which are plastic drums lined with plastic bags. I think that should be sufficient for the ales.

They used to have in-line aeration and propagated their own yeast, but got rid of it b/c they found that the additional work was not needed.

Go figure.


Questions about the forum? / the action buttons on the "recent posts" page
« on: November 30, 2012, 04:37:48 PM »
I find the action buttons on the "Recent Post" page very useful. But have others also noted that they don't correctly relate to the post? If you look at the post you would think that the buttons in the same gray box belong to the post. But that's not the case its the buttons at the top of the next post that belong to a given post.

I doubt we can fix this, but maybe Simple Machines should fix this down the road. I think a few times in the past I have replied to the wrong thread.


Yeast and Fermentation / yeast for Shock Top Wheat clone
« on: November 26, 2012, 06:54:58 PM »
Does anyone know what yeast would go well for a Shock Top Wheat clone? My wife likes this beer and want's me to brew a beer just like that.

When I had the beer I didn't notice phenolics, so the yeast should not have the typical Belgian phenolic character. The Witbier strain descriptions from WL and WY mention phenolics which is why they may not work as well.

Are there any commercial Wits from which I can culture yeast?


Yeast and Fermentation / Foam stability and oxidation
« on: October 19, 2012, 02:29:41 PM »
I don't always point to my blog articles here but I made an interesting observation last night:

The beer on the left, the one with the coarse bubbles was bottled w/o O2 and the one on the right was. The difference in foam stability is astounding. But I have to admit that this was only one bottle against another one. It's likely that the O2 didn't cause this difference and I have to see how other bottles of this beer pour.

I don't think many are playing with intentional beer oxidation, but I think brewers should. I know Fred noticed better aging through oxidation. Maybe O2 at bottling time can become a respected technique even though it flies in the face of conventional brewing wisdom.


General Homebrew Discussion /
« on: October 17, 2012, 03:36:06 AM »
Have you guys seen this:

I stumbled across this today. An aggregation of all sorts of brewing content on the web. I like the non cluttered display and that I made the cut :)


Equipment and Software / Microscope use in brewing
« on: October 07, 2012, 04:05:55 AM »
I finally finished another article for the wiki. This time it’s about the use of a microscope in brewing and it covers:

-required features
-cell counting
-methylene blue staining
-and more

Check it out here: Microscope use in brewing


Yeast and Fermentation / Where do I get EDTA?
« on: September 25, 2012, 03:30:56 PM »
I asked WhiteLabs how to unflocculate heavy flocculators like WLP002 for cell counting. They replied that I have to add EDTA (Ethylenediaminetetraacetic acid) or sulfuric acid. Both seem to be chelating agents, which makes sense since they can steal the calcium that is needed for flocculation.

I rather not deal with sulfuric acid if I don't have to. So I was looking to get EDTA, but it doesn't seem readily available. They sell calcium disodium EDTA in health food stores. But I wonder if it's still able to chelate more calcium.

Cynmar does sell EDTA, but not to individuals. They don't sell chemicals to individuals unless its a buffer or a dye.

Any other ideas how I can unflocculate WLP002. This yeast doesn't even unflocculate in the presence of maltose like most other flocculators do.


Commercial Beer Reviews / Are there any good beer apps for Android?
« on: September 09, 2012, 12:46:05 AM »
I have beer cloud. But I'm looking for an app that helps me keep track of commercial beers I like and don't like. The latter is pretty important since I have forgotten that I didn't care for a particular beer and bought it again.


Yeast and Fermentation / surprisingly low wort fermentability
« on: September 08, 2012, 05:28:27 PM »
Last weekend I brewed a Hopfenweiss inspired Weissbier IPA. I was shooting for highly fermentable wort with 30 min rests at 150, 144 and 150 F. When I got back the FFT results I was very surprised that i got only 75 % apparent attenuation.

I'm not sure what happened here. Maybe the Pils and wheat malt didn't have enough diastatic power?

But this was a good opportunity to start an experiment on diastatic enzymes during fermentation. So I put about 600 ml each of the beer into 1000 ml fasks. To one I added only water as the control to account for the lower OG that the others will have. To one I added some Beano and the last one received a 10 Plato wort extracted from malt with a 30 min mash at 140 F. This leaves most of the b-amylase intact and should kill proteinases and most of the bacteria.

This morning I saw quite some activity in the flask with the malt extract. There is also some activity in the Beano flask. I may have to add some some. I didn't know how much Beano is needed since brewers are generally advised against using it. Very little activity in the control fermentation.


On their Yeastbuddy White Labs released analytical data from an aeration and olive oil experiment they made a while back:

What's interesting to note is that there was no real analytic difference between the beers. I speculate that this is because the yeast already had enough sterol reserves. After all, they know how to grow yeast well.


General Homebrew Discussion / Buffalo Wild Wings and home brew
« on: August 31, 2012, 03:10:32 PM »
This just came in through my club's email:

Making fun of homebrewers:

Enjoy :)


The Pub / Hi there
« on: August 01, 2012, 01:49:29 AM »
I thought I'd say hi again. Sorry for the relatively sudden disappearance a while back, but when you have to prioritize time, hobbies end up suffering the most.

I hope I can spend a little more time in the forum again. Brewing and geeky stuff in isolation is not as much fun.


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