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.

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.

Today’s plan for WBC: Hops 1, Barrel aging, and more?

Well, due to the lack of free wi-fi at the Hilton yesterday, I blogged the whole thing on my phone. Not fun. Today we’re at the convention center and I’m expecting there to be wi-fi so that I can use the iPad, which will actually be rather excellent in comparison.

Today I plan to attend the Hops 1 technical session, and Barrel aging. I don’t see much else on the schedule today that would catch my attention more than these (even skipping the keynote this morning, as Columbia Sportswear’s Tim Boyle doesn’t really lift my sails).

I’ll do my best to post stuff again today, so stay tuned.

Update: You’re telling me that wi-fi at the Oregon Convention Center costs $13 a day for 128K download speed? Have I found a wormhole to 1994?

This is ridiculous. No way am I going to do this on my phone again. I’ll have to take notes and paste them up later. Sorry.

Sensory Workshop, WBC

Sitting in on (and lending a hand to) the Sensory Workshop for craft breweries.   It’s an all day event, and right now Annette Fritsch (Boston Brewing) is giving an overview introduction. 

More updates to follow as I think of them.

Update: Annette is explaining the importance of separating your preference for a beer from whether or not it tastes like it should. As a panelist in a production facility, you will likely be tasting some beers that you dislike (I know I do), but you must resist the urge to mark the sample down and instead focus on how close the sample is to what it should taste like. Very difficult.

Update 2: Teri Horner (MillerCoors) is covering raw material sensory analysis. They check their dilution water (apearance, taste, flavor) every FOUR hours!!

Update 3: Just before lunch, Amanda Benson (Deschutes) introduced a small handfull of flavor standards and explained their origins and characteristics. Later, they will pass out 3 blinded samples and quiz the attendees as to their identity.

Now, Annette is back and discussing sensory methods for QA.
In/Out method: testing whether samples are in or out of your normal variation (go/no go). Hard to do statistical analysis on this simple data. Intensive for panel leader, as identification of issues can be subjective. +: short, easy to train, simple. -: no descriptive information, subjective, need lots of data, directly impacts the release of products so it can lead to bias (“we need to ship this beer!”, or “I will have lots more work to do if we destroy this beer”).

Degree of Difference:
You know samples are different (via diff tests), degree of difference tests can tell you how different.
+: less time and resources than full descriptive profiling. -: useless unless attributes are specified and panelists are trained, cutoffs must be established.

Some discussion of Difference from Control (an article on this already exists on this site; I’ll skip it here).

Update 4: Next up, Gwen Conley from Port Brewing/Lost Abbey to discuss intermediate/advanced training.

Panel types: acceptance, difference/descrimination, production release, profiling. Most of this talk on descriptive profing. She has little information on her slides, and her oratory is fast and all over the place so we’ll see how much of this I can record…

Now she gives examples of scales and intensity rating for basic tastes. They’ve passed out more tasting samples for a demonstration: ketchup, for example, where flavors are broken apart and rated on their intensities.

Shelf life: hold beer at cold, room temp, and hot (partially for micro reasons, not absolutely necessary). I think hot (85-90F) is useful to an extent, as it can give you a rough idea of how products behave differently which can be useful for solving issues further upstream.

Package/product interactions: can liner material can pick up aromas, so take care where they are stored. “Garbage truck caught fire outside Ball plant, and cans smelled like burnt electrical wire, fish, diapers, etc”.

Update 5: Now welcome Lindsay Guerdrum, from New Belgium, discussing in-process tasting. What to do if malts are mixed in a silo? If a fermentation is moving too slow? Without in-process tasting, you may not catch this until it gets too expensive to fix. It saves money and time and resources to have this type of tasting procedure. It keeps products consistent for you consumers. Validate your panelists continually with spiked samples to ensure they are trained and sensitive. Who to put on this panel? Validated, knowledgable of your products, consistent, unbiased (yeah right), unemotional, communicative people. Define and establish: anomalies, who monitors and communicates issues, where and when in the process it is tasted. Make sure you have support from management and tasters; get them to buy-in. Build a profile of the flavor of your beers at different stages of production for comparison. Write decision trees and SOP’s for different scenarios. Hold a blending panel to determine acceptable blending ratios for anomalous beers. Comunicate results. Track anomalies to watch for patterns and pre-empt further issues.

Update last: the round-table expert panel, with the above folks and Lauren Salazar (New Belgium). I think I’ll just leave it here, since this will be all over the place. If something noteworthy comes up, I’ll mention it.

Countdown to World Brewing Congress, 2012

The Hotel Monaco here in Portland is quite nice. I got here a couple days ago to handle a couple of projects for The Company prior to the beginning of WBC, and my time here so far has been pleasant. I went to the Brewer’s dinner which kicked off the Oregon Brewers Festival, and it was alright. Just way too many people; I hate huge throngs of people, especially when they all congregate around the beer tables even though they are not currently getting beer; they really need to put a zone in front of the tables that is reserved for people actually getting beer, and if you want to “hang out” you need to go off somewhere else. The beers I had there were a lime Kolsch from Burnside Brewing (obvious lime flavor extract, a bit too artificial for me even though I love a good kolsch), Hopworks IPX (nice, but a bit too biscuity for me), a couple pilsners whose identities elude me at the moment (obviously very memorable!), and Gigantic Brewing’s Axes of Evil beer (the full name of which reminds me of a show dog’s stage name – it was quite a mouthfull). This last beer was my favorite. It had a very unique aroma which I struggled mightily to identify; it wasn’t something I’d really encountered before. But I was nearing the end of my desire to stay there any longer, so I didn’t really feel like getting more to analyze it further. Maybe I’ll run across it again some time. The last two nights, friends and co-workers and I have been haunting the Shanhai Tunnel bar on 2nd and Ankeny. It’s a bit of a dive, but I like that and one of their bartenders makes a mean Caipirinha (yum). Where to go tonight? We’ll see…

Tomorrow, the pre-Congress seminars start, and unfortunately I’m not registered for any of them (an extra $200 almost for each one). There may be a chance I can get in to some of them since I know people who are involved with about 3 of them or so, but we’ll have to see what happens.

When the Congress officially starts I will do my best to make a few posts about what I see, but typing a bunch of stuff out on-site with an iPad may be a bit too awkward. I may start a post in the morning and gradually edit it to add more as the day progresses, or I may just wait until I get back to my room to record my thoughts. I have no idea what’s going to happen, but I’ll try to give you some glimpses here and there.

Btw: need info about WBC events schedule and such? There’s an app for that! Google Play and the iTunes app store both have this free app, and it has all sorts of information. Pretty handy.

Finally, I apologize about any typos over the next week: the iPad is highly inconvenient for the accurate typing of lots of text.

Not really a new post

Well, seeing as though I rarely find myself posting here, I suppose all that this site is good for anymore is the archive of posts I’ve managed to assemble. I haven’t forgotten or ignored the site over the last couple months, but I certainly have not been doing much with it. Every once in awhile I get a comment that needs an approval or a reply, but apart from that I’ve had very little time to actually post more content. I still want to post more at some point so I’m not abandoning the site by any means, but I certainly can’t say that I’ll be a prolific poster. The sensory department here at my company is growing by leaps and bounds with new systems and procedures being added all the time, and this means I tend to have little time to do stuff like write for this blog.

That being said, next week I’m traveling to Portland to attend the World Brewing Congress. This is a large meeting of brewing industry professionals and academics from all over the world, held every 4 years. I went to the one in San Diego in 2004, and that was awesome (had an excellent introduction to authentic Brazilian food at Rei do Gado, as well). I hope this year is just as exciting; having a look through the program I see that there are a number of talks and symposiums that sound interesting.

While I’m there I hope to have the opportunity to write some posts (and tweets and the like) about the material I find and the people I meet, so stay tuned! There’s a link to the WBC site in the banner to the lower left if you’d like more information.

The final word on beer serving temperature.

Sounds a bit arrogant, eh? Well, follow along and we’ll see if you disagree.

It seems like every week I run across some sort of discussion about what temperature to drink your beer at. These conversations usually involve some people (who are often fairly well educated in the various topics of beer) enlightening the beer n00bs of the best way to serve, pour, and drink various beers. This “best way” is most often dependent on the style of beer in question, with lagers being served colder than ales and other ideas like that. Well, I’m here to tell you that is a bunch of bollocks.

Now, don’t get me wrong: everyone who drinks or eats anything should know that volatile flavor compounds are more readily released and detected when the sample is warmer. The same with agitation: when you stir, swirl, swish, or chew your sample (be it solid or liquid) you’re allowing more volatiles to be released. Also, controlling serving temperature has great importance when conducting sensory experiments, not only for ensuring that all samples are treated in the same way, but also to maximize (or whatever the goal is) the chance of picking up certain flavors. These are all fundamental ideas in flavor science.

But beyond these considerations, my point is that once you are armed with that knowledge you should be free to enjoy your food or beverage in whatever way you like most. There are a number of instances where a beer will taste better when it is colder than it does after it warms, regardless of the style. I’ve experienced this many times, particularly when drinking beers from small microbreweries who may not have the control of quality parameters that larger breweries have. Some beers will be wonderful and defect free when drank below 40F, but after the beer warms in your glass some of the ugly defects that you didn’t notice earlier start to come out. Diacetyl is usually the culprit here, but it can be other flavors as well. Plenty of times I’ve opened a can of Heineken and poured it into a frosty glass and enjoyed the first half, but by the time I near the end of the glass oxidation flavors are starting to make themselves apparent and the beer becomes far less tasty. In these cases you almost NEED to drink the beer cold, regardless of whether it is an ale or a lager, just to enjoy it. Another reason I enjoy my beer colder is that it’s more drinkable and refreshing, and yes, I often like my ales drinkable and refreshing. Sometimes when flavors hide behind the coldness it can make the beer easier to drink. For example, beers that have higher alcohol and a lot of solvent-like flavors can be tamed when drank colder, while they can sometimes get more aggressive and unpleasant as they warm.

What might bother me the most about this serving temperature topic is when a pub will assume that this is the best temperature at which to serve their beer. Sure, it may be better for delineating the subtleties of the beer flavor, but what are those extra 10 degrees doing to the stability of the beer? It’s allowing the beer to oxidize and age that much faster, so while you may be trying to appreciate the beer now you are also making a poorer quality beer for the next pint.

What it boils down to is this: don’t tell me how to enjoy my beer. I know how and when to use serving temperature to achieve different goals, but when I am drinking beer because I just want to drink a beer, I will serve it at the temperature that I want it at, not what you think it should be. And I encourage you all to have the same mind set: if you like your IPA at 35F, that is your call and I won’t ever have a problem with it. I just hope you’re not under the impression that all the flavor you taste is all the flavor there is in that beer.