In light of the lambic that we are making next I have been doing some research into what I need to do to make it as authentic as possible. One of the things that is traditionally done with lambics is to use aged hops. This might sound a little strange because it goes against the traditional handling of hops, but there is a method to the madness. Basically the idea is to age the hops so that the acids have broken down to produce no bittering components. This is partially because lambics are not supposed to have hop flavors, but the primary reason is for preservation. There are too primary things in beer that preserve them, one is alcohol, but the other is hops. It turns out that traditional lambic isn’t very alcoholic at all. The BJCP style calls for original gravity between 1.040 - 1.054 sg and 5-6.5% ABV, so the hops are important for preservation.

This got me thinking about how I was going to find hops with low enough acid to get some preservation qualities from them without imparting hop bitterness or flavor. I did a little googling and came across a 2004 article from brewing techniques that focused on how to preserve your hops. More importantly it provided equations on how to fairly accurately calculate acid loss over time. So I figured I would try to calculate if any of the hops I had lost enough acid to be used. I did order 3 lbs over a year ago and still have some left.

In the end it turns out that I-2 years in cold storage in a vacuum sealed container really only drops around 2% acid, which is not enough to make a difference on anything but Saaz. So that doesn’t help. So instead I will probably just get some Saaz now, stick it in a paper bag in a warm room and maybe in 30 days or so the hops will lose 1% of acid. Saaz is only 2.5% to begin with, so it should be the best option.

The formula used to calculate the acid loss is shown to the right (FA = ...). It is comprised of six variables, two of which should be readily known (A and D), and one that we are calculating (FA). The other three (K, TF, SF) have there own derivations depending on some other factors. I will describe these three below:

• Rate Constant (K): this constant represents the rate at which your hops lose their acid. Over time hop brokers developed an index called the Hop Stability Index (HSI) which reflects how much acid is lost in six months if stored at 20° C (68° F). Typically this information is presented in the form of a % loss by hop suppliers. In fact if you go to hopunion and check out there variety guide you will see this defined under storage ability. You can also calculate the % lost using the HSI if you have that instead. To calculate K, you need to use values for the original acid value (Ao) and final acid value after 180 days (An). Obviously, you won’t have either, but you can calculate the original acid value, and use a arbitrary value for the final acid value because the calculation is a ratio. The equations for calculate this are to the right. 
• Temperature Factor (TF): this represents the affect temperature has on the storage. It is expressed as an exponential decay function, starting from 1 halves itself every 15 °C (27° F). So for example if you stored the hops at 68°F the TF would be 1.0, at 41°F - 0.5, at 14°F – 0.25. The equation for this is again in the image to the right.
• Storage Factor (SF): this represents the affect the storage container has on the aging. 1.0 for “Not sealed or sealed in poly bags”, 0.75 for “sealed in barrier packaging or airtight jars, but not free of oxygen”, 0.50 for vacuum sealed. That last value seems to be calculated by the auther using experiments.

Have have just summarized the equation specifics. There is more information in the posting. I have also created a Excel spreadsheet that does some of the calculation for you.

The September ‘08 issue of BYO has an interesting article on buffers that describes in pretty good detail how they work. The chemistry is slightly over my head, but I am able to make enough sense of it to understand the main points.

To start, it helps to know that PH is equivalent to the negative log of Hydronium ions (ph= –log |H30+|), which essentially means the concentration of hydronium ions. In water, a difference from the neutral ph of 7 occurs when the levels of H+ and OH- ions become unbalanced. Concentrations with more H+ have lower PH and are hence considered acids. Concentrations with more OH- have a higher PH and are hence considered bases. It’s best not to stray too far from the Hydronium description, because this is the heart of how buffers work.

Essentially, a buffer is a combination of a weak acid and its conjugate base, that when placed in solution balance each out in a way that holds the PH of the solution at a particular range. It’s not until additional acid is added at significant levels to overwhelm the balance that the PH can then drop at a standard rate. How does this work, its fairly intriguing actually. Take carbonic acid (H2CO3) and bicarbonate (HCO3) for example. Note that the difference between the acid and the base is at least one hydrogen ion. In solution the acid would disassociate one hydrogen ion and combine with water to create a new Hydronium ion (H30+). The extra hydronium ions would then combine with the extra CO3- ions to form a new HCO3+ or H2CO3+ ion. This process will continue in equilibrium holding the PH steady until additional acid is added is sufficient quantity to overwhelm the extra CO3- ions. This explains how Buffer 5.2 is able to hold the PH in the 5.2 range and why sometimes when adding acid you hit plateaus where the PH doesn’t change much.

The other aspect of buffers is the buffering capacity of the grain and produced wort. One of the primary bi-products of wort production are proteins to break down the starchs into sugars. This proteins are primarily composed of amino acids which also effect the PH of the wort. Amino acids are composed of a central carbon atom surrounded by 4 arms of ions depending on the type of amino acid. At a certain PH, called the isoelectric point, an amino acid will have both negative and positively charged arms. The resulting molecule has a neutral net charge and will buffer a solution at the isoelectric point, which is different for each amino acid. This type of molecule is called a zwitterion (german for hermaphrodite) because of the opposing charged arms. “Just as a weak acid and base will buffer a solution, a zwitterion will buffer a solution at its isoeletric point. If a acid is added to a solution, the minus end will absorb some of the hydrogen ions. If a base is added, the plus end will absorb some of the negation ion.”

The important thing to take away from the amino acids is that they are in greater concentration in the wort than the buffers in your brewing water. This means that the PH of your brewing water really isn’t that important. The article suggests that because of this the PH of your mash will be in the 5-6 range without any additional acid or bases, but I have never tried tested this. I have always used buffer 5.2 in the mash and adjusted the PH down to 5.2 using a little lactic acid. I will test the PH next time before the buffer to see what its stabilizes at. Unless my brewing water has some serious minerals, I imagine the article may be correct.

The plan for the next brew is a Doppelbock, something akin to Celebrator but probably a little darker like Sam Adams dark lager. I’ve been wondering the best way to achieve this level of darkness while still maintaining the clean flavors they you get with a lager. The doppelbock style is generally a pretty rich flavorful lager so some degree astringency and bitterness from the dark grains would be acceptable, but probably not in the levels needed to get proper balance.

Lucky for me the September ‘08 issue of BYO has a good article on debittered black malt, which I have never heard of before. The dark malt is processed specifically to reduce the bitterness and astringency of the malt but still retain the ability to get dark color in your beer. This is perfect for the Doppelbock style that requires rich clean flavors with a dark color.

Both Weyermann and Dingemans produce versions of this malt. Weyermann has a 320, 400, and 525 °L called Carafa Special I, II, III. All which are made from German 2-row spring barley. Dingemans debittered black malt is made from European 2-row with ratings between 525-600 °L.

The MDHB does show either of these as available but maybe the Frederick or Annapolis ones do, haven’t checked yet. If not I;m sure I can buy some online.

Was reading through the October '08 issue of BYO and low and behold the "club PROFILE" article was on a club in Carroll county, my county (and Johns).

I've definitely been interested in finding a good club in the area, but have been reluctant because the pages always seem fairly bland and un-organized. I think I did see this club before when looking for one online, not sure why I didn't check into it. Maybe it is because they don't seem have a lot of events posted. One of the things that was cool about My San Diego trip a few months back was that I was able to meet a friend at a local bar during a homebrew meeting. It would be cool if clubs in the area sponsored frequent events like this, even if they were only monthly. Maybe I will reach out to one of the members and see what's going on.

For more info go to their website. They appear to have a active yahoo group, but for some reason it won't let me in, just keeps sending through an infinite loop of logins. WTF.

I enjoyed this book very much. Both from a brewers perspective, but also in learning some of the science and history behind the Belgian styles that rely on bacteria. I read the book over my summer vacation at the beach in North Carolina, so it’s somewhat out of mind. If only I started the blog earlier, I would have the content fresh in my mind for review, but I don't so I'll do my best.

Classic Styles

The book mainly discusses a few styles of beers that come from the Belgian region that rely on native bacteria in the air and on fruit to aid in the fermentation of beer. These styles are:

• West Flanders Red: reddish brown to deep burgundy in color. Ofter called the "Burgundies of Belgium," because of color and consistency. Some are fermented with a pure strain of brewer’s yeast and some with both yeast any bacteria. Typically aged in oak for 3 years, bottle conditioned, sweetened, and pasteurized. Tends to be much more tart and sour than the Flanders brown style.
• East Flanders Brown:  redish brown to brown in color. Often referred to as an "Oud Bruin". Usually much more bitter that the reds though "mellowed by a malty sweetness". Typically fermented with a "mixed culture of yeast and bacteria and subsequently aged in stainless steel tanks at higher temperatures"
• Traditional Lambic: pale yellow to deep golden in color. Often bitter with a lactic sourness, mellowing with age. Aged for 6 months to 3 years depending on what it is blended with
• Gueuze: lambic made with 1, 2, and 3 year old lambic

Lambic

There are tons of interesting notes in this book on lambics, most important is understanding how these beers were traditionally made. Lambics are traditionally spontaneously fermented, which means they are purposely placed in a area that has decent amount of airflow from a nearby field or orchard. Typically the wort is placed in large cool ships in the highest part of the brewing building. A cool ship is essentially a long, wide, shallow vessel for holding beer. It's primary purpose being spreading out the beers so that as much surface area of beer comes in contact with the air. This enables the beer to cool quickly, but also provide inoculation with wild yeast and bacteria from the air. So the cool ship is generally considered to be the primary fermentation vessel for this style of beer.

There are several breweries that still spontaneously ferment there beers, but many will also add isolated strains of bacteria, or simply use a blend of isolated bacteria strains instead of spontaneously fermenting. Coolships and open fermentors can still be used in these cases, difference being better control over what goes into the beer for fermentation.
Fruit in lambic was and is often a common way of changing up a lambic to create a new and complex beer. Fruit is also a great source of bacteria and yeast because they live on the skins of the fruit. As a result the fruit was also a common source for the bacteria inoculation needed.

The Bugs

There are many types of bacteria and yeast that play a role in fermentation of beer, but the most commonly recognized are listed below:

• Brettanomyces: Most important bacteria for wild beer production. Includes 5 recognized species, the most common being B. bruxellensis. Brett is a super attenuating yeast(near 100%), which means it can break down any type of sugar (simple or complex) if given enough time. This behavior "is attributed to, in part, the ability of beta-glucosidase inherent in Brettanomyces". More on that in a follow up post.
• Lactobacillus: plays major role in the fermentation of flanders beers but a smaller role in lambic. It's claim to fame is that it can ferment in the presence of or lack of oxygen. It's primary bi-product is lactic acid. The most common species is L. delbrueckii.
• Pediococcus: provides the majority of lactic acid found in lambic. Will ferment glucose into lactic acid without the CO2 by product produced by other bacteria.
• Saacharomyces: Literally named "sugar fungus," is the primary source for brewing yeast. The S. cerevisiae is used in ale fermentation while S.pastorianus and S. uvarum are used as lager strains. Other strains such as S. globosus can often be naturally found in a lambic fermentation
• Enterobactor: most notable for providing flavor compounds to young lambic (1-2 months). Only survive for a short period of time during fermentation because they cease to reproduce at a ph of 4.3. This is a good thing because in the same family of bacteria are E. coli, and E. Salmonella

 

Turbid Mashing

Lambics use a different kind of mashing method that does almost the opposite of what brewers today are doing with regard to sugar extraction from the grains. Typically brewers want highly fermentable wort which means mostly simple sugars (saccharides and disacharides) with few dextrins because they are not fermentable by standard brewer’s yeast. Lambic brewers on the other prefer wort with high concentrations of complex sugars (dextrins) because the highly attentuative brett used to ferment it produces more flavor and complexity in the resulting beer by breaking these complex sugars down.

It should also be noted that the history of turbid mashing actually stems from the tax situation in in the early 19th century. The beginnings of this mashing style date back to a 1822 dutch law that fixed a duty upon the capacity of the mash tun. To limit the impact of the duty, brewers created small mash tuns and filled them as full as possible with grain. As much liquid as possible was added and a lot of mixing was done. Liquid was continually drained off and later re-added with more water. The details of a turbid mash outside the scope of this post, but there is a good article describing it in the latest BYO. Essentially the result is wort with high concentrations of dextrins, which the bugs love.