Archive for the ‘Brewing’ category

Ben Johnson asks the question we all should have: Why does sexist marketing still exist?

February 2, 2017

Ben Johnson is a beer writer who twice (2014 and 2015) was voted “Best Beer Writer in Ontario” at the Golden Tap Awards. His blog, the aptly named Ben’s Beer Blog, should be required reading for anyone who makes or drinks Ontario craft beer.

Ben has posted a significant piece about the ever-present sexism in our craft beer industry, Let’s Talk About Sexist Beer Marketing in which he beards the lion in its den by contacting offending brewers and asking them why they have taken the low road.

Read his blog. Contact the breweries mentioned and tell them they are creatively sterile and lazy. Drink someone else’s beer.

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Iron Brewer: The planning begins

July 23, 2015

Yes, it’s that time again. The Master Brewers’ Association of Canada (MBAC) has just released the list of ingredients for the 2015 edition of the Iron Brewer competition.

For those of you who have joined this channel since last summer, the MBAC provides 15 brewers with identical bags of ingredients. Each competitor must make at least 10L of beer using only the ingredients provided plus brewing water. (Just like Iron Chef competitors don’t have to use every ingredient on the pantry table, Iron Brewers don’t have to use every ingredient in the bag.) The beers are judged, the scores are toted up, and one brewer is crowned the Iron Brewer.

Since there are always more than 15 brewers interested, names are drawn from a hat, with the exception of last year’s 1st, 2nd and 3rd place finishers, who are given a bye into the next competition.

Here are the ingredients in the bag this year:

Base Malts:
Czech Pils, OIO 2-row, Weyermann Vienna, Simpsons Pale Ale Golden Promise

Specialty malts:
Briess Smoked Cherry Wood Malt, Bairds Carastan 30/37, Chocolate, Simpsons Light Crystal, Simpsons Double Roasted Crystal, OIO Toasted barley, Weyermann Carabelge, Crisp Clear Choice, Harvest Malt & Hops

Hops:
Admiral (13.6% AA), Celeia (4.3), Pilgram (9.0), Jarrylo (14.8), Pekko (15.4) + whole leaf from Harvest Malt & Hops & possibly Winterbrook Farms

Yeast:
Belle Saison, Munich Classic wheat, Abbaye belgian, S23 Lager, US05 Ale, Fermentis Abbaye

Special Ingredients:
Oak Chips, Sarsaparilla, Whirlfloc

There may be some additional ingredients added by the end of next week. I have until the end of September to brew at least 10L of beer with only the above ingredients + brewing water.

Does anyone have suggestions on what type of beer I should make?

Iron Brewer Throw-down

December 2, 2014

Yes, it’s been over two months since I last blogged. Here’s what happened: a BIG project. Back in the summer, I was given responsibility for creating an on-line version of our History of Brewing course. So that’s what I’ve been doing ever since. It started off as a normal project. But, like Audrey II in Little Shop of Horrors, the project began to grow and take on a life of its own. By the end of the summer, I was working on it seven days a week. By October I was working on it seven days a week, often from 8 am until 1 or 2 in the morning. It’s done and dusted now, doubtless a real achievement in the annals of on-line education. I’ll blog about the whole thing later, once the nightmares and flashbacks have calmed down.

However, now that I have a life again, let’s return to the matter at hand — the Iron Brewer competition some eight weeks ago.

In case you need a reminder, the Iron Brewer is an annual competition held by the Master Brewers Association of Canada (MBAC), where all the entrants get an identical bag of ingredients, and have to make at least 10 litres of beer using only what’s in the bag plus brewing water. I had chosen to make a strong Scotch ale.

View from my table. Nice place.

View from my table. Nice place.

This year, competition judging happened at Amsterdam Brewhouse,  a brewpub down on Queen’s Quay at the Toronto waterfront. It’s a very nice location, right beside a marina, if you can get there — for the past two or three years, Queen’s Quay has been a construction zone, raising the challenge of Toronto traffic from impossible to nigh impassable. But finally I and my cooler of Scotch ale arrived.

My wife’s coworkers had suggested possible names for my beer, and I was particularly taken with “Highland Gale Highland Ale”. (I came soooo close to using “Big Jimmy”.) I didn’t print labels this year, but I did have a graphic on the table of a highland warrior laying about with a claymore.

Last year, my table was pretty Spartan compared to some of the other displays of grain and hops brought forth by competitors. I had every intention of creating a better display this year, but… well… anyways.

table

My table, as Spartan as last year

So my table was a bit barren again.

This year, Elaine wasn’t able to make it, so I didn’t have anyone bringing me beer samples from the other competitors. I did manage to slip away a couple of times, and man, the other beers I was able to taste were fantastic this year! Andy Preston, who came in second last year, was at the table next to me, and had concocted a delicious brown ale. (That’s actually a pun, because he had used a double decoction method to make the beer. “Concocted”. “Double decoction”. Get it?)

<crickets>

Never mind then.

The special ingredient in the bag this year was heather tips, and many took advantage of this. Victor North, who with his wife Sonja has started up Garden Brewers in Hamilton, had made something incredible with the heather tips, although the exact style escapes me right now. (It WAS eight weeks and a lot of beers ago.) Siobhan McPherson also used the heather tips — again, I can’t remember what the style was, but it was good. A fellow Brewmaster graduate, Chris Freeman, now brewmaster at Collingwood Brewery, brought a delicate heather-spiced English mild. Current third-semester Brewmaster student Caleb Gilgan eschewed the heather tips in favour of the oak-smoked wheat malt, brewing up a crisp and lip-smacking smoked Oktoberfestbier.

crowds

This was early on. It got way more crowded.

While the judging was going on, I tried to describe my beer to each drinker: a nose of wild honey, a full rounded palate, with soft notes of caramel leading to a lushly sweet finish. Or words to that effect. However, it got quite crowded, and noisy, making erudite and witty commentary impossible By the end of the afternoon, I was pretty much reduced to pushing beer into people’s hands and screaming, “Yaaaaaaaaaaaaaar!”

trophy

Organizer Paul Dickey hands me the trophy. No, I don’t know what the object on top of the trophy is.

After a couple of hours of judging, it was time for the winners to be announced. Third place went to Ian Johnston — unfortunately I didn’t get a chance to sample his beer. Second place went to Victor North for a beer I hope Garden Brewers produces commercially. And for first place: me.

“Gobsmacked” is not a word I commonly use, but for the first time, it was perfect: I felt gobsmacked. There was some fantastic beer there, far more complex than my simple Scotch ale, but apparently Highland Gale Highland Ale had achieved some sort of zeitgeist. Huh.

Of course, I am never at a loss for words, so when I was handed the mic, I held forth: “Errr.. Ummm… Uhhh… Thanks.”

Since that time, my fame has known no bounds. People stop me on the street.

Okay, I’m lying about that part.

However, Jon Downing, the brewmaster at the Teaching Brewery, borrowed my recipe, and last week, I helped mash in what will become about 400 litres of the Highland Gale Highland Ale. It should be available later in December — perhaps in time for Christmas!

 

Chocolate Decadence

March 23, 2014

A few weeks ago the college had a “Chocolate Decadence” festival. This event is mostly a chance for the culinary department to show off — chocolate, after all, is the theme. However, the organizers also wanted to offer a 1-hour seminar that would focus on chocolate-based foods and the college-brewed beers that could be paired with them, and a similar seminar pairing chocolate with college-made wines. I was asked to lead the seminar on beer and chocolate, and my counterpart in the wine education program, Britnie Bazylewski, was asked to handle the wine seminar.

Shortly after receiving our Decadence seminar assignments, Britnie and I had a brilliant idea while we were munching on Skittles. (Britnie keeps a supply of Skittles on her desk, which I have to eat if I feel like Skittles, because even if I had a supply of Skittles on my desk, I’d never find them under all the papers.) The brilliant idea, undoubtedly fuelled by Skittles sugar, was that it would be much cooler if we joined forces and offer two identical seminars that would pair both beer and wine with various chocolate dishes. If that wasn’t enough, we also decided that it would be way more fun to present chocolate-based foods rather than straight chocolate.

cocloco1During the weeks leading up to the event, Brewmaster students created six beers to pair with the food. Working with the culinary department, we developed a menu of chocolate-based foods that were perhaps outside the usual range of what you might think as chocolate. And that was the gist of our seminars as well — we knew everyone was going to go home from the festival bursting with chocolate-y ideas of what to serve to guests next weekend, but inevitably it was going to be either chocolate fondue or chocolate cake. We titled our seminars “Going Coco Loco”, and as the name suggests, we wanted people to think outside the box when it came to both chocolate and the wines and beers to serve with them.

Ancho Chili Soup with Cocoa

Ancho Chili Soup with Cocoa

Our first course was Chili Ancho Sopa de Chocolate — a smooth spicy Mexican soup made with blackened ancho chili peppers and enriched with semisweet chocolate. I think a lot of people in the seminar were expecting Britnie to present an icewine — it’s the usual suspect when eating chocolate-based foods; but Britnie instead pulled out a 2012 College Rosé. The sweetness of the Rosé’s residual sugar helped disperse the heat of the spices, and its light body contrasted well with the thick soup. On the beer side, in the first seminar I chose to pair the spicy soup with a Vanilla Cream Ale that had been devised by Teaching Brewery Brewmaster Jon Downing and made by a group of 1st-year Brewmaster students. Like the wine, this beer was on the sweet side, which tamped down the heat of the soup, and the vanilla flavour went well with the cocoa notes like vanilla and chocolate ice cream in the same bowl. In the second seminar, I used the same reasoning but with a bit more oomph, pairing the soup with a Russian Imperial Stout devised and created by 2nd-year student Graham McMullen.

Pulled chicken sliders with Mole Negro

Pulled chicken sliders with Mole Negro

The second course was Pulled Chicken Sliders with Mole Negro — spiced with three types of chili peppers, some garlic, a bit of canela, some almonds and sesame seeds, and of course , some chocolate. For the wine, Britnie picked a 2010 Dean’s List Meritage, a Bordeaux-style with enough body to match the blackened spices. For the first seminar, I chose Chocolate Cherry Schwartzbier, again one of Jon Downing’s recipes that was created by 1st-year students. This sweet beer is normally paired with black forest cake, but I wanted to try it against the black mole sauce, and I think it worked well. For the second seminar, I paired the chicken sliders with 2nd-year student Mark Lewis’s modern take on an ancient Aztec beer recipe, something he calls “Xocolotl”. This big (10%) beer has both sweetness and some fairly significant spicy heat, so matched both the blackened spices and the cocoa in the sliders.

Cocoa-Rubbed Baby Back Ribs

Cocoa-Rubbed Baby Back Ribs

The third course was Cocoa-Rubbed Baby Back Ribs — just what it sounds like: ribs rubbed with a combination of cocoa powder, brown sugar, ancho chili powder, and some spices. Mmmmm! Britnie’s wine was a 2010 Cabernet Sauvignon with lots of tannins for the meaty ribs. My choice of beer at both seminars was 2nd-year student Tanner Hinrichsen’s “Spicy Orange Ale”. Tanner confessed that he is not really a fan of chocolate, so he set out to make a beer that would pair well with chocolate without using chocolate or dark malts. The result is a light amber ale with strong citrussy orange notes and a bit of heat. This and the ribs made for a great combination.

Baba Ghannouj with White Chocolate

Baba Ghannouj with White Chocolate

Our final course was White Chocolate Baba Ghannouj with Spent Grain Crisps — a fairly standard baba ghannouj with the rather unusual addition of some white chocolate. Britnie chose the 2011 Niagara College Semi-Dry Riesling, which had enough acidity to cut through the thick body of the baba ghannouj. I chose another of Jon Downing’s recipes, French Coffee Porter. Although this has very noticeable coffee flavours, those actually come from one of the grains used, French Coffee Press malt. I thought the coffee and white chocolate made a good combination.

Britnie & I going coco-loco.

Britnie & I going coco-loco.

Perhaps the best part of the seminars was that the college was fortunate enough to receive a generous sponsorship from nearby Inniskillin Wines that allowed us to offer the seminars for no cost. Yep, free food and drinks, woo-hoo! Everything tastes better when it’s free.

In the end, everyone went home with some ideas for a chocolate-based dinner that will hopefully colour outside the lines, and Britnie & I were left with the task of coming up with some more great recipe ideas for next year.

If you would like a copy of the recipes for the four dishes served at our seminars, contact me at studentofbeer@gmail.com

MBAC 100th Anniversary Conference: Part 3

February 24, 2014

Still at the 100th Anniversary Technical Conference of the MBAC. With fermentation and history finished, it was time to move on to filtration.

Beer Haze & Colloidal Stability (Karl Sibert, Professor of Biochemistry, Cornell University)

If you’ve left beer in your fridge a long time, you know that eventually the beer will start to get hazy. First the haze only appears when the beer is cold but then disappears when the beer warms up — the classic “chill haze”. Leave that beer for a while and the haze becomes permanent, regardless of temperature. There is no way to prevent this increasing haziness other than by reducing the amount of haze-causing (or “haze-active”) particles in the beer before you bottle it.

As Professor Sibert explained — this was actually a reiteration of material we had covered in several classes of the Brewmaster program — hazes are caused by protein-polyphenol complexes that start as tiny particles but gradually clump together into larger and larger particles. Protein particles are hordein, which is found in barley (and for wheat beers, from a protein called gliadin.)

Dr. Siebert’s research shows that since haze-active proteins and haze-active polyphenols combine to create haze, it follows that reducing haze-active proteins by 50% should reduce haze by the same amount.

He also suggested that silica gel, a filtration aid now gaining favour with brewers, works by attaching itself to haze-active proteins, thus not allowing competing polyphenols to attach. If a significant number of the polyphenols are unable to bind with the haze-active proteins, beer haze will be reduced significantly.

Beer Filtration: The Current situation and Future Outlook (Ernst Meier, M & L Consulting)

We started with a look back at the past 70 years of beer filtration.

The 1940s saw the development of mass filtration or deep-bed filtration, where beer was passed through a very long box filled with cotton or sometimes even asbestos. In the 1960s, the excellent filtration properties of diatomaceous earth (the microscopic fossilized silica skeletons of a prehistoric hard-shelled algae, better known as kieselguhr in Germany) were discovered. The first DE filters were “plate and frame” style — cotton “plates” stretched on frames and covered with DE were clamped together and beer forced through the apparatus. In the 1980s and 1990s, DE filters using circular steel plates, either horizontal or vertical, were developed. These were soon followed by “candle” filters.

The interesting thing was not the development of this technology, but the relative cost of the filter: In the 1960s, 90% of your filtration cost was tied up in the filter itself. Today, the cost of the filter is only about 28% of your filtration cost — the other 72% is being spent on a complx web of tanks, pipes and peripherals, including in-line syrup dosing, flash pasteurization and in-line CIP (clean in place).

You would think it would be obvious, but many brewers run into problems by installing new filtration systems without regard to their existing systems. Apparently a recurring problem is installing new equipment in the old space, depsite the fact that it requires more space than the old system. What usually occurs is a lack of space for proper maintenance and access to the new systems.

As we heard earlier with regard to fermentation tank design, pre-planning a new filtration system is paramount.

Best line of the presentation: “Employees always make the same mistakes. Engineers always make new mistakes.”

Centrifuge Optimization and Maintenance (Marco Garcia, MillerCoors)

Large centrifuges are becoming popular with brewers as a means of quickly and efficiently removing yeast and other “large” particles from the beer before fine filtration. This reduces the load on the fine filters, and also speeds up filtration times. A modern centrifuge has a stack of metal cones inside it, with a clearance of a few microns between each cone. Yeasty beer fresh from the fermenter is forced in between the cones while they are being spun at 30,000 rpm. The yeast and other “heavy” particles are forced to the outside wall of the centrifuge and are drained away, while the now-clear beer is forced to the centre of the centrifuge, where it is drained to the next step of finer filtration or to a holding tank.

This can remove yeast from a very large volume of beer in a short time, but there some caveats. This is not a machine you want to run if you have the slightest doubt about maintenance issues. It is a big heavy machine with parts that are spinning incredibly fast — if anything were to happen, I would not want to be in the same building, let alone standing beside it.

At MillerCoors, they have discovered that measuring the discharge is essntial to optimizing performance. If the discharge starts to drop off, there could be a problem. They have also installed sensors that can detect if a shaft bearing is starting to fail. In addition, MillerCoors has instituted a schedule of cleaning and preventative maintenance that include semi-annual major overhauls, timed to avoid the busy summer brewing season. All of their American operations now use standardized maintenance practices, and maintenance personnel are trained to follow a Standard Operational Procedure (SOP).

Next up: Barrel Dwellers

MBAC 100th Anniversary Conference: Part 2

February 20, 2014

The first two parts of the conference had been about cellaring and fermentation. The next part of the conference was brewery history.

Sleeman Brewery (John Sleeman)

Sleeman started as a small brewery on the outskirts of Guelph, Ontario, but through clever marketing of clear glass bottles (bad for beer but nice to look at) it rapidly outpaced the other small breweries in the area and became a national player. The founder, John Sleeman, is a very personable guy, very able to sell himself — and that has probably been one of his strengths during the long and sometimes difficult road he has followed while building Sleeman to the size it is today.

He related some of the stories behind the advertising we see on TV — the references to “pirates” and “smugglers”, and how his father was forced to close the family brewery in Guelph when the Sleemans were caught providing beer to American smugglers during Prohibition. How John started a brewery armed with nothing more than his grandfather’s recipe book and the promise of technical expertise from Stroh’s, was a fascinating story.

He had several pieces of advice:

  • Be brutally honest about your own skills, and find people to fill in the gaps you have.
  • Don’t hire friends and family. First, it’s too hard to fire them when they mess up. Secondly, other employees will always believe that friends and family, no matter how skilled, get promoted due to nepotism.
  • Don’t underfund your start-up. More companies die due to lack of cash flow rather than bad product or poor sales.

Mill St. Brewery (Joel Manning)

Mill St. was a “3rd wave” craft brewery that started as a tiny operation in the touristy Distillery District of downtown Toronto  in 2002. Smart marketing to women of a rather bland low alcohol organic beer in a smaller-than-normal 200 mL “pony” bottle caused sensational sales and growth. (During an informal tour of their brewery last summer, one of the brewer showed me their fermenter schedule — “Organic Ale” still makes up over 60% of their production.)

Joel was brought on in 2005 to oversee construction of a brewhouse out in the dreary eastern suburbs of Toronto — an area called Scarborough on the map, but better know as “Scarberia” to locals.

Things were not easy for Joel — the industrial building for which Mill St. had signed a lease proved to have inadequate water, electricity and sewage capacity. However, problems got solved with the application of more money. (As the experts say, “Set a budget and schedule, then double the money and triple the time.”) Mill St. definitely did not build a showcase brewery — it is located in an anonymous industrial building in an anonymous industrial district. Mill St. has never publicized the new brewery location, and many people probably believe their beer is still brewed in the Distillery District.

Once the new brewery was in operation, the original brewery back in the Distillery District was converted into a brewpub.

 

MBAC 100th Anniversary Conference: Part 1

February 19, 2014

A couple of weeks ago, I attended the Master Brewers’ Association of Canada (MBAC) Annual Technical Conference. What made this one a bit special was that the MBAC was founded a century ago. Unlike the Ontario Crafter Brewers (OCB) Conference last October, which included seminars about marketing and event planning, the MBAC conference had a strictly technical focus — how to make beer, and how to make it better. Here is a summary of the various seminars.

Design of Fermentation and Maturation Tanks (Michael Kurtzweil, Ziemann International)

Ziemann is a German firm that manufactures fermentation tanks of all sizes. I remember them most for the tanks they made in 2010 for Molson — six massive 4500 hL tanks. (Each could hold about 1.4 million bottles of beer.) The tanks were shipped across the Atlantic to Hamilton (right next door to my town of Burlington), then put on trucks and then slowly and gingerly moved along back roads to Molson’s Toronto brewery. One of those back roads was about 2 km from my house. The move took ten nights, and required approval from the province of Ontario and six different municipalities since it involved lifting up hundreds of telephone, cable and hydro wires at intersections, as well as temporarily moving stoplights.

Michael Krutzweil’s first remark about buying fermentation tanks was that master planning is essential right from the beginning. Rather than thinking small and then scrambling for more fermentation volume, he advised brewers to “Think big, and start small”. Rather than ordering a tank when you need it, he advised us to plan ahead to when we think we’re going to need it, and order it well in advance to lower costs. This past summer I had personally seen several small breweries out in B.C. that had just opened their doors and were already trying to shoehorn more fermenters into a limited space because of unexpectedly robust sales, so this seemed like good advice.

When planning your tank farm, think about tank location. Are they going inside or outside? If outdoors, are they shiny showcase tanks, designed to be admired by the general public? Or are they going to quietly sit in a back lot, unseen?

Whatever the case, Michael suggested that you spend the money to ensure they are held high enough off the ground so that there is lots of working room underneath. Later on, as your brewery grows, this will allow you to install a pipe fence underneath them. (A pipe fence is a permanent grid of pipes and valves that allows you to move wort and beer hither and yon without stopping to attach and detach rubber hoses and pumps.)

What else should you plan on for the future? Flexibility seems to be the key:

  • If you increase the pressure capacity of your fermenters to 1.5 to 2.0 bars, the tanks can also be used as bright tanks to carbonate the beer.
  • Many tanks have pipes for water, cleaning solution, CO2, etc. welded directly to the top of the tank. However, Michael suggested having a removable dome plate bolted to the top of your tank instead. That way your pipes aren’t welded directly to the tank. Later on, if you want to change the arrangement of pipes or even the number of pipes, you simply replace the dome plate rather than replace the entire tank.
  • Speaking of a dome plate, what if you made the dome plate out of polyurethane rather than stainless steel? Some of New Belgium’s brewers found stainless steel dome plates too heavy to lift, but polyurethane plates were considerably lighter, and apparently have not affected performance.

Other things to consider for the future include insulation, glycol jacketing, access to the top of the tanks (ladders or catwalks?), security against earthquakes and high winds, and how new tanks are going to be moved to the brewery, especially the very large ones.

Yeast Management (Christopher White, White Labs)

White Labs is one of two major yeast suppliers in North America, so getting Chris White at the conference was impressive. The first point he addressed was the question of reusing yeast. Because yeast reproduces, it is theoretically possible to use the same batch over and over again forever. However, a batch of yeast can lose its efficacy over time due to mutations, lower viability and a loss of vitality; most breweries opt to replace the entire batch of yeast after a set number of uses (often ten batches). Chris says it all depends on how the brewery handles the yeast during

  1. Storage,
  2. Propagation and
  3. Pitching

1. Storage

When storing yeast, apparently the key to keeping maximum flavour and stability is to avoid changes in the environment and or environmental stresses — these will force the yeast to rapidly adapt to the new environment, causing mutations. Keeping the yeast in an anaerobic environment at -80°C will avoid both growth and mutation.

2. Propagation

During propagation — growing the yeast from a single test tube to 100 litres or more —  it’s important to get started soon after thawing out the yeast — never leave it sitting in a Petri dish for months at a time. Fresh wort is often used as a growth medium — this adapts the yeast to the stuff it’s going to be swimming in for the rest of its life, and wort also has all the nutrients yeast requires for growth. However, add the yeast to as small a volume of wort as possible — this reduces the risk of microbial infection due to competition for scarce resources. And remember to constantly agitate the flask to improve circulation of nutrients and oxygen. (Yeast need oxygen in order to grow rapidly). Chris cautioned that your lab has to be completely aseptic: tiled walls and floor, foot baths, HEPA air filtration, UV lights, and positive air pressure. And he suggested when propagating that you avoid volume increments of more than 10:1 during each step or forcing growth too rapidly.

For instance, he suggested that if we started with 10 mL of yeast and kept to volume increments of just 10:1, we could get as much as 100 litres of yeast in just over a week:

  1. Add 10 mL of yeast to 8°P wort and aerate and agitate the wort at 25°C for 1 to 2 days
  2. Move 100 mL of this slurry to a larger container of fresh 8°P wort and aerate and agitate the wort at 25°C for another 1 to 2 days
  3. Move 1 L of this slurry to a larger container of stronger wort (12-16°P) with more aeration and agitation at 22°C for yet another 1-2 days
  4. Finally move 10L of this to a very large container of 12-16°P wort for 2-3 days at 22°C.

Follow these four steps and in 5-9 days, you should have 100 litres of yeast slurry ready for use.

Chris also threw in some other considerations:

  • Using pure oygen rather than air will produce healthier yeast with thicker cell walls.
  • Watch for sources of contamination — when you are plating yeast, for instance, air-borne microbes can infect the Petri dish.
  • The wort temperature during propagation is usually higher than wort temperature during actual fermentation. Chris advises that towards the end of propagation, wort temperature be decreased so that, again, the yeast has a chance to gradually adapt to actual working conditions without being forced to mutate.
  • During propagation, transfer yeast to larger containers during its active growth phase (after 1-2 days), not after active growth has stabilized.

3. Pitching

Yeast can usually be used 5-10 times without problem. The usual pitching concentration (which I remember from Microbiology classes) is about 107cells/mL/°P. That is, about 1 million cells per millilitre of wort for every degree Plato of sugar — the more sugar there is, the more food there is for yeast cells, so there can be more yeast cells per millilitre.

(How do you estimate the concentration of yeast cells if your brewery doesn’t own a microscope? Put some yeast slurry into the fridge and let it cool for a day. The yeast will fall to the bottom of the container and form a thick white goo, while the liquid floating on top will be clear. If the yeasty goo makes up about 1/3 of the container, your concentration of yeast cells is (very) approximately 10 million cells per mL.)

If not handled properly, yeast can become infected by other microbes such as pediococcus or lactobacillus. You can “wash” the yeast with dilute acid, killing the microbes, but this has two effects. One is that it will also kill off some yeast cells, lowering your yeast’s viability. The other problem is that once you have acid-washed your yeast, it seems to become more susceptible to infection — from that point on, you may have to acid wash that batch every time you want to reuse it.

Lastly, Chris took a question from the floor about using olive oil during fermentation rather than oxygenating the wort. (You add oxygen to wort in order for the yeast to use the oxygen to construct lipids that can then be used to build cell walls. This allows for rapid and healthy reproduction. By adding olive oil to the wort rather than oxygen, the theory is that the yeast cells will use lipids directly from the olive oil rather than having to build them; hence, no need for oxygen.) In answer to the question, Chris replied that New Belgium had done some experiments with olive oil and had subsequently measured increased ester levels (fruity aromas) in the resulting beer, but the esters did not reach levels detectable by the human nose. The answer seems to be that the idea requires further research.


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