Good news: A new post is coming!

Bad news:   It’s not exactly beer-related.   But is is related to microbiology, food safety, and kitchen sanitation!    And there is a dearth of real information about this specific topic on the web right now so I figured since I can address the topic with original “research”, I’ll put it up here on the blog so others can gain knowledge from it as well.

That’s all I’ll say about that until the results are in.  Expect it in 1-2 weeks, but I have a backpacking trip scheduled for next weekend, so I hope to post it before that.

I’ll also consider what other topics I can post about that are beer-related, as I know I’ve been VERY delinquent in that regard.

 

Considering new material, and a relevant event announcement

Hello BSS readers,

I know that it’s been awhile since I’ve written, but that should come as no surprise by now.    I have been spending some time recently thinking about how guilty I feel leaving this blog inactive for so long, and considering some material I can post soon.   I’ll do my best to get something up when I can.

Also, I’d like to mention that I’ve received correspondence from a colleague of mine about a beer sensory workshop that he will be running during Seattle Beer Week.    On May 18th at Pyramid Brewery Alehouse in south Seattle, there will be two 90 minute sessions where Ian McLaughlin, of Craft Brew Alliance, will explain sensory science and beer flavor, and will present a number of flavor standards and other types of samples.  It sounds like essentially the same type of material that goes up on this blog, so it could be pretty interesting!

Here is a link to the workshops.  It is $30, but it sounds like that could also get you a free tour of Pyramid Brewery and discounts on food and drink.   And if I can swing it, maybe you’ll even see me there…

http://www.seattlebeerweek.com/events/681-Beer-tasting-Beer-Judging-101

Tickets:

http://beer101sbw-srch.eventbrite.com/

New Year, New Job, New Posts

Hello BSS Readers, and Happy New Year!

I hope the recent holidays have found you well. Again, I shall apologize for the lack of material that’s been showing up here. The last several months have been rather busy, I guess. I don’t really have a good excuse, but I do have some exciting news! I’ve got a new position in my company! In the next few weeks I am moving out of the quality control lab and taking a brand new position in the company (created just for me). This position will be part of a corporate-level service group designed to solve problems for the company. Part of my job will be to train *all* of our panelists across the company, which I’m actually already doing but this will be in an official capacity and will be more involved and will likely mean more traveling. Another part of my job will be poking through mountains of production data to look for issues and solve problems, and to create reports for the big wigs. I’m pretty excited about all the changes it will be bringing.

Once the dust settles after this transition (like the training of replacements, completion of remodeling projects, etc) I expect that I will have a little more time to put into this blog. I have some material from WBC that I still need to post, and I think I’ll have some other things to discuss as well by that time.

So, onward into 2013! This blog ain’t dead yet!

Macrobrews: “Crap on Tap”?

Perusing the latest issue of BeerAdvocate, I found a letter in the Feedback section referencing an article that I could tell I just had to find: Andy Crouch’s “No Crap on Tap” article.

In this article, Andy lambastes the tendency for many craft/micro beer drinkers to describe beers from the Big Breweries as inferior, poor quality, “crap”. He bemoans the use of catchy rhyming cliches, like saying that your favorite pub has “No Crap on Tap” or, in other words, they don’t sell any Budweiser or its ilk.

It’s refreshing to hear more people voice the position that these macrobrews are far from “poor quality”. It’s something I’ve been saying for years.

In a nutshell: these beers are made to extraordinarily tight specifications, from the raw materials all the way the to finished package quality. They are made to meet amazing levels of consistency from different production facilities across huge geographical distances . The lack of flavor that they have compared to craft beers is not, in fact, a mark of inferiority but rather the mark of a beer that has nowhere to hide any flaws: the slightest slip-up in production means that faults in the flavor would stick out like a sore thumb.

What YOU should do about it: feel free to express your opinions about how lovely or how terrible that beer tastes. But realize that they are just that: opinions. Try not to conflate your opinions with your perception of quality.

Analytical 2:

Analytical 2:

TALK 1: Recent discoveries in beer foam, Karl Siebert, Cornell

Best foam seen with lowest pH (3.?) and mid-range ethanol (5%), in an ovalbumin, isoalpha acid model system. Very simplified, so not totally accurate.

Above pH data was disputed in a study with actual beer (more foam at higher pH), so something was missing in the model system.

With an unmalted barley protein extraction, a higher pH and mid-range ethanol showed most foam, proving a better system than the ovalbumin model.

Seems like LTP1 protein is the main protein involved, and the interactions are mostly hydrogen bonding.

?s: should use malted barley as changed in proteins occur. Yes, I’m not done with this research yet. LTP1 has been shown to be responsible for gushing, does this disprove that? It may be a matter of degree, where normal beer hs the right conditions for moderate foam production.

TALK 2: Critical review of the measurement of carbon dioxide in packaged beer, Donald Hutchison, AB-InBev

Most instruments use pressure/temperature method. Must attemporate and equilibrate sample, correct for air altitude, and package volume.

TALK 3: CO2 solubility in wort and beers, R. Alex Speers, Dalhousie University

When is the beer saturated with CO2 (when bubble formation starts in fermentation)? pH, sugar, ethanol effects?

ASBC measurement is based on undefined reference standard beer, (sg 1.01, changed 1.015 for unknown reason. No chart or formula has provided justification. No presentation of data analysis of error. Formula says

ASBC method possibly used 95% of the value of CO2 solubility in water.

CO2 is 10x more soluble in ethanol than in water, so why does higher etoh content in beer have a negative influence on solubility as per the formulas?

(Findley, Shen, 1911, J. Chem Trans). The only report on CO2 solubility in beer?!

Why do we measure CO2 at higher temps? More accurate for reading gauges.

Need a tested and unified method, which includes factors for pH, ethanol, and extract, not just T and P.

?s: some reports on solubility ARE available, different formulas are available in the soft drink industry, although they also can’t establish origin. Now, ASBC methods have to be based on published papers. Have you investigated how large differences have to be until we can perceive differences in carbonation? Very small study showed no perceived visual differences from 2.2-2.7vol. (visual only?!?).

Barrel aging

Trilogy of Barrel aging

TALK 1: David Rosenthal, Chateau Ste. Michelle

Discussing barrel-making, oak growing regions and differences, differences in oak species

Sizes: 10-600L barrels… up to oak tanks, which are used for rieslings, as they do not much impart much oak flavor, but some mouthfeel.

Empty barrels are more vulnerable to contamination, ozone is best for cutting microbial growth. Sodium percarbonate, soda ash and citric acid are also used.

Wine tasting: 5 chardonnay samples, different producers and barrels.

1: Boutes, American Oak
2: Barrel Associates, American Oak, deep toast, (tastes like fireworks)
3: Boutes, French Oak, subtle and simple
4: Dargaud and Jaegle, French Oak
5: World Cooperage, French Oak (more fireworks)

He describes differences here, but I’m not super great at picking out barrel-based differences in wines.

TALK 2: Dr. James Osborne, Oregon State

Barrels are “good” for microbial growth due to rough surface, semi-porous so some access to oxygen, wood sugars can be used by some microorganisms (Brett).

Acetobacter: bad, almost always.
Lactobacillus: used to be used in ML fermentation (wine), now considered spoilage.
Pediococcus: can produce ropiness (extracellular polysaccharides) and lots of diacetyl.
Brettanomyces: “british brewing fungus”, a survivor, difficult to diagnose via microscopy, slow growing, poor competitor with Saccharomyces, don’t need oxygen but it can stimulate growth, can utilize many sugars even trehalose and ethanol, can penetrate up to 8mm into barrel staves.

Brett flavors: Lactones (b-damascenone), volatile phenols (4-et phenol, 4-et guaiacol), acids (acetic, isobutyric, isovaleric), alcohols, esters, lipid oxidation products.

Barrel maintenance: cannot fully eliminate all microbes, but topping off, use inert gasses, keep bung area clean, isolate infected barrels, santize thief, store empty barrels with compounds mentioned in TALK 1 (ozone is most popular).

TALK 3: Femke Sterckx, Wood Aging and Monophenols

25 different monophenols in wood-aged beer, many with vanilla or spicy characteristics. Precursors are lignin, hydroxycinnamic acids, some are bound in glycosides. Oak aging is often with oak chips. More wood chips are associated with higher monophenol content. Various compounds are more related with medium toasted barrels while others are more associated with heavy toasted barrels. Higher ethanol, higher lagering temperatures, and low pH helps with monophenol extraction.

Please excuse typos and shorthand. I tried, I really did. But the trip to Shangai Tunnel and elsewhere has left me sapped of the energy to proofread this material. Enjoy if you must.

Hops 1

Hops 1:

TALK 1: Influence of fermentation compounds from yeast on the quality of hop aroma, hitoshi takemura et al. , kirin

How can two breweries with same hop conditions result in beers of different hop aroma intensities?
Hypothesis 1: Biotransformation of hop oils by yeast?
Hypothesis 2: Do other yeast based compounds (esters) affect the perception of hops?

Testing 1: Results from GCMS does not support, as linalool levels are the same in “lower” beer (linalool is a typical indicator compound of hop aroma).

Testing 2: added esters and higher alcohols to beer (at ppm, and ppb levels, respectively) and tested by expert panel. Esters seemed to have no effect on hop fruity flavor, while higher alcohols (especially 1-pentanol, 1-heptanol) showed a suppression effect on hop fruity flavor. This supports hypothesis 2. Next, fermentation temperature (17, 21oC) and yeast pitching levels were tested. Again, put in front of small trained panel: temperature had a larger effect (higher temp leads to lower hop fruity flavor), and pitching rate had a less robust effect (higher pitching rate showed lower hop fruity character). Questions from audience: does aeration affect? Didnt test. Did you propagate yeast from same source? Yes. Were the spiked samples representative of normal beers for higher alcohol content? Yes (eg. 10-20ppb heptanol).

TALK 2: Aroma and Harvest maturity of hops, Daniel Sharp, OSU grad student

How does harvest time affect aroma chemistry, with Cascade and Willamette hops in particular? (hop oil in hops, not beer).

Hops from two farms, 2 years (2010, 2011), 3 harvest dates (early, trad., late). In triplicate. Extraction via ASBC steam distillation method, detected by HPLC and GC-FID. Harvest timeline: difficult to time the harvesting as “traditional” harvest time is usually a guessing game. Yearly climate differences also uncontrollable. Sample-sample variation between hop collection was large (three collections from whole hop field for each farm/variety).

Hop Storage Index: Very little difference due to harvest time.
Alpha acids: drop in the cascades at late harvest.

Cascade: (i cant keep up, moving too fast!).
Willamette: most terpenes increased over whole study, even into late harvest.
Sensory: only on cascade, difference test. Difference noted, so consumer acceptance test was performed. Trad harvest were preferred. Descriptive: late had more onion and garlic

Essential oil increases past harvest date for willamette, cascade stays constant or drops a bit.

?s: Bob Foster: Did you control kilning temps? Yes, 120F. Practical considerations for farmers? Need to nail down good useful predictor. Pellets vs whole? Used Whole. Did you look at dry matter content with harvest dates? No patterns, all over the place. Glycosides? No, Shellhammer will speak to that.

TALK 3: Patricia Aron, MillerCoors (and OSU)

Phenolic profiling of lager beers during aging in relation to hopping technology.

Some background on hop polyphenols, beer stability.

Hypothesis: hopping regime affects the phenolic profile over aging …(ack, too fast!). Focussing of flavonoids.

Method: 12p base wort, lager, Chelan hops. Accelerated aging (6 weeks). Hop treatments: control- no iso’s and no hop polyphenols; pellet- iso’s and hop polyphenols; spent- no iso’s with hop polyphenols; extract-alpha acids only.

Many analysis methods, broad and specific. Chock-a-block with chemistry, but it’s too fast too keep up with here. Increase in total polyphenols in aging, then a drop off as it ages further. More specific analysis of flavanoids/proanthocyanidins: spent hop beers were the highest (expected, due to the nature of the spent hop product). Spent hop beer saw the lowest increase of aldehydes over aging of the treatment beers. Methional (potato!) was the dominant aldehyde found in aging. no significantly different in trans-2-nonenal. Kettle hopping (pellets) did not augment proanthocyanidin content in beers. Hopping regime did not affect loss of iso-alpha acid content over aging. Brewing with hop products did not affect the antioxidant potential of beers by ESR (odd).

?s: what is the standard or definition for “spent hops”? There isn’t. Are you confident in your analysis of proanthocyanidins? Difficult, some material is not susceptible to acid cleavage. Does freezing/thawing have an effect? Dunno, but maybe.

TALK 4: Contributions to hop aroma from the water-soluble fraction of hops. Tom Shellhammer, Oregon State

Used spent hop material (after supercritical CO2 extraction) in lager beer, analyzed with sensory and instrumental. Simcoe, Centennial, Citra, Cascade. Very low level of residual alpha acids (highest was 0.5%, ~98% of the alphas were removed in extraction). Also very very low in residual hop oils. 1g/L hop addition, 5min into 60min boil.

3 finished beers: One with pellets (normal), one with hop extract (like Miller), one with spent hop material (water soluble materials). BU range: 18-37 (pellets), 12-15 (spent). Alcohol, 4% by weight. Spent hop beer showed surprising amount of linalool (order of magnitude). Principal Component Analysis showed spent and pellet beers in their own clusters, with the extract varieties separating out from each other.

Sensory: Spent hop beer aroma showed lower hop aroma intensity, as anticipated.

Summary: evidence that spent hop beers produce aromas that are noticeable and significant, and dependent on variety (particularly Simcoe).

?s: how was sensory performed on finished beers? Randomized, 5 reps minimum, difficult to control temperature due to randomization. Does the flavor result in a desire to brew with spent hop products? Didn’t look at preference or hedonics, but unofficial tastings showed surprising acceptance.

Later:
Please excuse any typos or shorthand, it’s late and my BAC is approx 0.2%, and I don’t have the energy to proofread.