Archive for September 2012

Day 386

September 28, 2012

Big day in Business Ethics: the first day of our 10-minute presentations on various ethical dilemmas drawn from current affairs. Each one generated some discussion, but the one that had the class going was this: You buy a stack of beer for a house party, but it all doesn’t get consumed. The next morning, knowing you can’t possibly drink all of it, do you pour the excess down the drain, or do you give it to the university students living next door, knowing they will probably consume it to excess?

In Sensory Evaluation, we bid adieu to Chef Olson, as it was the end of his 4-week tenure with us. But not before we learned about stews. Stews are a great dish for a brewpub in the fall and winter, because they use cheap cuts of meat that are then braised and simmered to tenderize them. Mmmm… tasty and profitable. And of course, with the three stews we tried, there was also some beer to pair to them.

Next week we move on to another segment of the course: wine and spirits. Dang. (No, that didn’t really work. I’ll try it with a straight face this time, and shake my fist at the heavens.) Dang!!

Day 385

September 25, 2012

In Rock & Roll History, we discussed why 1950s society was such a fertile ground for rock & roll music: a much simpler time in some respects, with no computers, internet, portable music, battery-powered watches, cell phones, microwave ovens, CDs, VCRs, PVRs, surround sound, or even Tang. America feared Communist infiltration and atom bombs. Baby boomers were just starting school or being born, father was the breadwinner, mother was the housewife, an economic boom was spurring prosperity, the suburbs were growing, boys’ hair was short, girls’ hair was long, consumerism was on the rise, pressure to conform was uppermost, sex was a never-spoken three-letter word, and everyone wore good shoes everywhere.

Since I’m a baby boomer–yes, the only one in the class–I still think I’m under-dressed if I wear running shoes in public.

In FCF (Filtration, Carbonation and Finishing, remember?), it was all about fining agents. That’s the stuff that’s added to wort or beer to reduce haze issues. A fining agent does that by glomming onto yeast and small bits of protein, creating matrices of stuff that gravity can then drag down to the bottom of the vat.

How quickly this happens depend on the variables in Stoke’s Law:

Vs = 2/9 [(þpþf) x g x R²]




  • Vs = velocity of a settling particle
  • þp = density of the particle
  • þf = density of the fluid
  •  g = acceleration due to gravity
  •  R = radius of the particle
  •  µ = viscosity of the liquid

Essentially, if the density of the particle, the force of gravity, or the radius of the particle increases, the particle will fall to the bottom faster, but if the density or viscosity of the liquid increases, the particle will fall more slowly. However, density of the particles can’t be changed without changing your beer; likewise the density and viscosity of the liquid can’t be decreased without changing the quality if the beer. Gravity is fairly constant around the world. That means the only positive change we can make is to increase the radius of the particles. The good thing about this is that as we increase the radius of the particle, the falling velocity of the particle increases by the square of the radius. So if we double the radius of the particle, its falling velocity increases four-fold.

The easiest way to increase the radius of particles is to glue several of them together. We do this with fining agents, which have a positive charge, and can pull the negatively-charged particles together into a larger clump.

There are several types of fining agents, the most commonly used being isinglass, made from the swim bladders of certain fish like sturgeons, and Irish moss, made from a certain type of seaweed. We also covered silica gels and a compound called PVPP.

I was particularly fascinated by the way that Irish moss works. Its active ingredient is k-carrageenan, which normally is coiled into a helix shape. When it is heated, it unwinds into a long straight strand. Negatively charged particles are attracted to various positively-charged sites along this strand. Then when the molecule is cooled down, it snaps back into its helix shape, trapping the particles in its coils.

However, with a number of tests and projects coming up, I have little time to admire molecular structures: an on-line test in FCF tomorrow, a Business Ethics class presentation and 8-page report due next week, a completely costed Sensory Evaluation menu also due next week, a recipe and grist bill for an IPA also due next week, a class presentation in History of Beer in two weeks, and a Rock & Roll project proposal also due in two weeks. Better get typing.

Day 384

September 24, 2012

In Brewing Calculations, Matt Howell is ready to take over, so Kevin Somerville handed him the chalk and eraser. Today Matt did a review of last week’s hop calculations, then led us on to yeast calculations, specifically, how to calculate the pitching rate and the total number of yeast cells needed for a particular batch of wort.

Having the proper number of yeast cells working on your wort is important–too few can mean the yeast are quite comfortable living on the oxygen you so generously provided, so they may never be forced to resort to anaerobic fermentation to survive. But too many yeast cells may result in a lack of resources for the yeast cells–sort of like planting too many flowers in your garden without enough fertilizer.

As we learned last year in Intro to Brewing, we normally want 1.1 million yeast cells per millilitre of wort per degree of Plato. That is, at 1°P, you want 1.1 million cells per millitre; at 2°P, you want 2.2 million cells per millilitre, at 3°P, you want 3.3 million cells per millilitre; and so on.

(This makes sense–higher gravity is an indication that there is more sugar in your wort, so obviously you would want more yeast to gobble up the extra sugar and make tasty tasty alcohol.)

The formula is a two-step process:

Step I:   r = Y  x °P


    • r = the pitching rate of yeast cells/mL needed
    • Y = the constant of 1.1 million yeast cells/mL (or in scentific notation: 1.1 x 106 cells/mL)
    • °P = specific gravity of the wort, expressed in degrees Plato

Once you have arrived at the pitching rate per millilitre of wort, you then simply multiply by the number of millilitres of wort you have to arrive at how many yeast cells in total you need for the entire batch:

Step II: n = r x V


  • n = total number of yeast cells needed
  • r = the pitching rate derived from Part I of the formula
  • V = the cooled volume of the wort, expressed in millilitres

Once you’ve done this a few times, you can combined the formulae into

n = (Y x °P) x V

For instance, the pitching rate for a 70 hL batch of wort (70 hL = 7000L = 7,000,000 mL or 7.0 x 106 mL)  with a specific gravity of 12°P would be calculated as

n = (1.1 x 106 cells/mL x 12°P) x 7.0 x 106 mL
= 1.32 x 107 x 7.0 x 106

= 9.24 x 1013 (or 9,240,000,000,000,000) total yeast cells needed

The next step–which we will cover next week–will be to take a cell count of your yeast slurry to determine how many viable yeast cells per mL of slurry you have, then calculate how much yeast slurry you need to add to your wort.

On to History of Beer, where Bill White covered the Age of Empire Building: the story of great conquerors, brave explorers and beer. Julius Caesar toasted his legions with beer, Martin Frobisher sought the Northwest Passage in 1576 fortified by 84 tons of beer (and was forced to return to England when the beer ran out), and the first thing Spanish explorers did after conquering the Aztecs was set up a brewery.

The sheer scope of beer history almost makes one pause whilst lifting a beer to one’s lips… Almost.

Day 379

September 23, 2012

A Business Ethics pop quiz at 8:30 a.m. D’ohh!

Well, perhaps “pop quiz” is a misnomer. We knew it was coming, and it wasn’t really a quiz, but there was no way to prepare for it, and it was worth marks, so I’m going with “pop quiz”.

Prof. Perry chose names out of a hat to randomly divide us into groups of three. We were given a case study about the role that the mortgage lender Countrywide Financial had in the subprime mortgage crisis of 2007. In  two hours, each team had to summarize the facts of the case study, then outline the various ethical dilemmas arising from this case, listing the various options for each dilemma.

Whew! Time to assuage our tired minds with a little artery-clogging fat. Yes, in Sensory Evaluation, Chef Olson introduced us to deep fried foods. (Not that anyone really needed any introduction to them.) In brewpubs, deep fried foods are often a profitable mainstay of the menu, partially because the dish can be prepared very quickly (faster turnover means higher profit), and also because using a deep fryer is pretty simple: submerge the food in hot oil until it turns a crispy brown. Drain. Serve. Cordon bleu chefs need not apply.

First Chef Olson went over the science of deep frying–dry heat versus moist heat, the typical kitchen set-up for a deep fryer, the fume hood requirements, the danger of dropping water or ice into hot oil,  the types of oil that can be used and their pros and cons, what causes the oil to break down, the theory behind breading or battering deep fried foods, and the various ways to prepare chicken wings.

The lecture carefully digested, it was time to move on to the tasting: mushrooms in both a typical yeast batter and a tempura batter; breaded zucchini sticks; and dusted spicy chicken wings. We sampled each against a Trappist ale, a British pale ale and a wheat beer, to see which pairing worked best for each dish.

For some reason, Sensory Evaluation is becoming the highlight of the week.

Day 378

September 20, 2012

I did say last week that I wasn’t going to say much about History of Rock & Roll since it’s an elective course. However, I thought I should share one of our major assignments: we are “required to select an artist, performance, song and/or album from the past 50 years and write a critical review that demonstrates both how and why it represents a turning point in the social, cultural and/or political history of the western world.”

Think about that for a few minutes while I meander on about other things for a while.

In the actual class, we covered the roots of rock & roll–slavery field songs, call & response, ragtime, jazz, swing, the blues, country & western and jump.

On to Business Ethics. We are preparing for in-class presentations about ethical dilemmas next week, so today’s class was spent in preparation.

And then Filtration, Carbonation & Finishing.

No wait, I have a confession to make: I skipped this class. (Which I thought was rather ironic, it being the class immediately following Business Ethics.) Here’s the thing. A couple of weeks ago, I wrote about helping to brew up a collaboration beer called Antipodean Wheat at House Ales. Tonight, the brewery I worked at during the summer had a “tap takeover” at barVolo in Toronto, and Antipodean Wheat made its debut. Filt/Carb/Fin is a very important class, but it was scheduled to go until 6:30 p.m., which would have gotten me into barVolo after 9:30 p.m. So if there had been a big run on Antipodean Wheat, I could have ended up not even tasting the beer I had designed–and how ironic and sad would that be?

So yes, friends, I skipped a class in order to be at barVolo by 6 p.m. to ensure I had a taste of my beer. As Hamlet said, “O what a rogue and peasant slave am I!”

But while I was there, I started every conversation with, “What album in the past 50 years has been a game changer for rock & roll?” (Not exactly the assignment as outlined above, but close enough for rock & roll, as they say.) Discussions were vivid and opinions varied widely. Nevermind by Nirvana. Highway 61 Revisited by Bob Dylan. Paranoid by Black Sabbath. A Night at the Opera by Queen.

The upshot is that I now have some excellent leads for my project… Which meant I was actually doing some homework, sort of… Right?

Day 377

September 19, 2012

In Brewing Calculations, we reviewed the calculations we learned last week for how much grain to use. However, that was a calculation that implied a single-grain mash, something that doesn’t happen very often. Luckily the formula for a multi-grain mash is identical, except that you make a separate calculation for each grain, multiplying the result for each grain by the percentage of the grist bill that the grain represents.

For example, if I’m making 50 litres of a beer that I hope will have an original gravity of 1.044 (11°P), in a brewhouse with an efficiency of 87%, using 60% pale ale malt (extract content of 80%,  moisture content of 4%) and 40% Vienna malt (extract content of 78%, moisture content of 3%),  our calculation would be

m = malt% x [(Vlitres  x  s.g.  x ° Plato) / (%extract x (1-%moisture) x %brewhouse efficiency)]

mpale ale = 60% x [(50 x 1.044 x 11%) / (80% x 96% x 87%)]= 5.16 kg

mVienna = 40% x [(50 x 1.044 x 11%) / (78% x 97% x 87%)] = 3.49 kg

Of course, simple math allows us to rearrange the formula to solve for any of the variables, such as brewhouse efficiency:

brewhouse efficiency = (Vlitres  x  s.g.  x %° Plato) / (m x %extract x (1-%moisture))

So if we make 50 L of wort that has a specific gravity of 1.044 (11° Plato), and we used 8.6 kilos  of malt that had 80% extract and a moisture content of 4%, the we can calculate our brewhouse efficiency as being

(50 x 1.044 x .11) / (8.6 x .80 x .96) = 87%

 That being relatively simple, we then moved on to calculating finished beer colour (usually expressed in North America as SRM–the higher the number, the darker the beer) from the colour and quantity of malt used. However, this is more of a guesstimate than anything. Yes, we can calculate the amount of colour the malt will add to the finished product, and probably for darker beers, it will be a pretty accurate estimate. However, for lighter beers, colour may be more dependant on how long the wort is boiled, since heat and water plus amino acids causes the Maillard reaction that darkens beer. For example, a light-coloured wort might be 2.8 SRM before the boil and 5.6 SRM after the boil. Hops can also have an affect on lighter beer colour, as will the degree of oxidation of polyphenols drawn from the grain husks, the amount of carbonates (water softness) in the mash water, and the amount of nitrogen in the grain (since more nitrogen equals more amino acids which means more Maillard reactions which means more colour).

Ray Daniels, in his excellent book Designing Great Beers, gives the formula

MCU = (°L x m) / V


  • MCU = malt colour units (a unit invented by Daniels — he does give a table for converting from MCU to SRM)
  • °L  = degrees Litner, a measure of the colour of the grain
  • m = mass of grain used, in lbs
  • V = Volume of wort in gallons

So 5 gallons of wort made from 8 lbs of  malt with a colour of 2.5°L will have a colour of

(8 x 2.5) / 5 = 4 MCU

(You can calculate the colour of a multi-grain wort by doing a separate calculation for each addition, then adding the results together.)

Of course Daniels’ formula is in American measures. For those of you smitten with the metric system, I realized  that using metric measures and then multiplying the result by 8.36 (2.2 kg per pound times 3.8 L per gallon) would give the same result:

[(3.6 kg x 2.5°L) / 19L] x 8.36 = 4 MCU

On to hop calculations. Last year in Brewing Ingredients, Kevin did teach us the formula for estimating the mass of hops needed to achieve a particular bitterness of beer:

m = (V x Cg x IBU) / U% x AA% x 1000


  • m  =  mass of hops needed in grams
  • V  =  volume of wort in litres
  • Cg =  correction for specific gravity if it is over 1.050: (1+[s.g. – 1.050)/2]
  • IBU = the number of bitterness units desired
  • U% = utilization of hops (see below)
  • AA% = the alpha acid content of the hops

The hop utilization table (U%) compared to boil time looks like this:

  • Dry hop = 0% utilization
  • 0-9 min boil = 6%
  • 10-19 min = 15%
  • 20-29 min = 19%
  • 30-44 min = 24%
  • 60 min = 30%
  • >74 min = 34%

This year, Kevin took us a step further: calculating multiple additions of hops at various times during the boil–say we want a projected bitterness of 65 IBU for a 60L wort with a specific gravity of 1.050, and plan to use Magnum hops (10% A.A.) for 60 minutes, Cascade hops (6% A.A.) for 10 minutes and Simcoe hops (12% A.A.) for 5 minutes. The Cascade and Simcoe additions are for aroma, so we would add them in pre-planned quantities of grams per litre, depending on how much aroma we wanted. In this case, let’s say we’ll add 1 g/L of the Cascade (60 g) and 2 g/L of the Simcoe (120 g).

By flipping around the above formula to solve for IBU, and borrowing numbers from the hops utilization table, we get

IBU = m x U% x AA% x 1000 / V

(Note that we don’t need a gravity correction factor since our s.g. is only 1.050)

IBUCascade = 60 x .1 x .06 x 1000 / 60 = 9 IBU
IBUSimcoe = 120 x .06 x .12 x 1000 / 60 = 14.4 IBU

Therefore the two aroma additions are going to contribute 9 + 14.4 = 23.4 IBU of bitterness. We then only have to solve for the mass of Magnum needed to produce the remaining 41.6 IBU:

m = 60 x 41.6 / .3 x .1 x 1000 = 83.2 grams of Magnum needed

We used the break between class to massage some feeling back into our calculator fingers, then it was on to History of Beer. Bill White led us down through the ages, looking at religion and beer, from ancient Sumeria and the goddess Ninkasi through ancient Egypt, Greece, Rome, the Bible, Aztecs, Mayans, Incans, African culture, Germanic tribes, the rise of mediaeval monasteries as centres of brewing.

Next week: beer moves out of the temnple and becomes a business.

Day 375

September 17, 2012

Brewmaster students sometimes get a chance to be a bit creative outside the college–but frequently you have to be flexible with regards to time–and sleep.

Earlier this week, I got a text message from my summertime brewery: would I be willing to come in early on Saturday morning to brew up a special beer of my choice on their pilot system for the upcoming Cask Days festival?


Saturday sunrise over Toronto: Hey, there’s no rush hour!

Well, yes I would. So it was that well before the sun arose, I was heading into Toronto, trying to get my brain going with a large double double. On the plus side: no rush-hour traffic on a Saturday morning.

Two weeks ago in Sensory Evaluation, Chef Olson had showed us a chipotle pepper that he had created by smoking/dehydrating a jalapeño pepper. Since then, the idea of brewing a spicy chipotle beer had been at the back of my mind. I was thinking of using a dark porter or stout as a base–smoked porters are all the rage in some places–but I didn’t want the roasted barley notes of the porter to overwhelm the smokiness of the chipotles. Hmmm. A black lager (known in Germany as ein schwarzbier) is noted for having no roasty notes. Hmmm. Okay, let’s go with the black lager.

So it was that I arrived at the brewery in the cold light of dawn clutching what was left of my large doube double and 500 grams of Black Prinz malt–a malted barley that is designed to add dark colour to a beer without adding any roasty, chocolate or coffee notes.

The brew went well, and boy, was it black. Dark black coffee black. Alas, the specific gravity was a bit lower than expected–I’ll have to check my recipe on Monday in Brewhouse Calculations. But it was black. Adding lager yeast to the wort made it, by definition, a black lager.

Next step while the lager is fermenting is to buy some jalapeño peppers. Oh, and find a smoker. And find out how to use the smoker. And smoke the jalapeños. And then doubtless buy a second batch of jalapeños. And then smoke them properly the second time around.

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