Posted tagged ‘technical conference’

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

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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.

Day 142

January 27, 2012

The Master Brewers Association of Canada (MBAC)–which is also the Ontario wing of the Master Brewers Association of the Americas (MBAA)–was formed to promote, advance, and improve the professional interest of brew and malt house production and technical personnel. For that reason, the MBAC holds an annual technical conference, and student members of the MBAC (such as myself and several other Brewmaster students) got in for the bargain basement rate of only $20, a pretty good deal considering it included six seminars, an open beer bar and a three-course lunch.

Admittedly, the three seminars in the morning were of more interest to us students: three brewers of wheat beers took to the stage to explain how they make their beer, and the challenges that brewing with wheat poses.

Although wheat beers still use barley, the grain bill can be up to 60% wheat. There are surprising differences between the two grains in terms of brewing.

Barley is a very brew-friendly type of grain, with a nice husk wrapped around its starchy interior. Before we brew with it, the barley is scrunched between two rollers to separate the husk from the starch. This “milling” has two purposes–it exposes the starch so it can be converted to fermentable sugars, and the husks will later form a grain bed through which the sugary wort will slowly filter, removing many particles from the wort as it is pumped over to the next vat.

In contrast, the problem with using wheat in your mash is twofold:

  • Firstly, wheat is a “naked” grain. It does not have a husk, meaning that the wheat will contribute nothing to the grain bed, which will be less thick as a result, and therefore much less efficient at filtering the wort as it leaves the lautering tun.
  • Secondly, wheat has a much higher percentage of protein than barley, and although some will be broken down in the mash tun, a fair proportion will remain in its original form. This has some positive effects–better head retention in the finished beer, for instance–but it also creates a host of problems. Large clumps of proteins can form a glutinous porridge-like blanket on top of the grain bed, bringing lautering to a complete halt. Because nitrogen needed by the yeast is still bound up in the wheat’s protein, there can be problems with the fermentation. And so on…

First up to describe his experiences with brewing wheat beers was Jerry Vietz of Unibroue, south of Montreal. Jerry took us through the history of Belgian “wit” beers–wheat beers made using unmalted wheat, coriander and curaçao–then some of the challenges he has faced, including stuck lautering and over-production of 4-vinyl-guaiacol (a chemical produced by Belgian ale yeast that in small quantities gives a Belgian wit a typical aroma of cloves, but in large quantities can be an offensive pungent aroma).

Next up was Jonathan Lowes of Molson, who took us through a rather technical talk about production of Molson’s Rickard’s White, also a Belgian wit. Unlike Jerry Vietz’s talk, where he freely talked about brewing methods used to produce various Unibroue beers, Lowes did not delve into actual production methods, possibly due to fears of disclosure of ingredients and production methods. One of the Niagara College Brewmaster instructors confided to me that much of the Molson segment was culled from standard texts on the topic.

The final morning session was Michael Hancock of Dennison’s Brewing, currently contract brewing Dennison’s Weissbier at Cool Brewing of Toronto. Michael gave us a brief history of his experiences with wheat beers, and some of the problems he had run into, particularly moving from a smaller system to Cool Brewing’s large brewing capacity.

Then the three brewmasters got together and led us in a tasting of all three of their products. Unibroue’s Blanche de Chambly was my favourite, the most aromatic and spiced of the three. Rickard’s White came in a surprising second in my books, mainly because Dennison’s Weissbier had dropped all its beautiful wheat haze, was as clear and bright as a regular beer, and lacked much of the taste and body associated with the protein haze. Michael Hancock admitted that in recent months, he has had trouble with the haze dropping out of solution after bottling, and was trying to find out why.

With the end of the morning sessions, the beer bar opened, and then lunch was served.

The three sessions after lunch were a bit less compelling to me:

  • the use of a new additive to diatomaceous earth (DE) filters in place of silica gels to improve filtering performance
  • more eco-friendly use of cleansers and sanitizers
  • setting up approved food-safety systems in the brewery

All in all, an interesting day, and much more comfortable chairs than found in the college’s classrooms.


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