If you want to play along at home, you have 4 options for making your own flavor standards. Let’s get this out of the way: three “official” ways of doing this are not cheap. But you pay for convenience, because while the third choice is generally cheaper, it’s also more labor intensive and in some cases not possible. With the resources available at The Company, I have the option of combining a fourth option with the first ones. So what the heck am I talking about? Read on…
Option 1: FlavorActiv capsules. This is the least palatable option for those without the budget, particularly because they are based in the United Kingdom which ups the price a bit. They are, however, extremely convenient. They come as color-coded capsules each signifying a particular beer flavor or defect. The list of available flavors is long, but they all run about 40-80 British Pounds for 5 capsules. Each capsule provides for 1 liter of beer at a concentration of 3X the threshold value for that flavor. You can adjust the concentration by using more or less than 1 liter, but at 3X you have about enough to serve 15-30 tasters, depending on how much they need to drink. The convenience comes in dosing: open the capsule, dump the crystals/powder in the beer, swirl to mix and serve. 43 flavors available.
[April 2016 Edit: Aroxa runs a similar outfit to FlavorActiv (in fact the man who set up FlavorActiv with their product split off and started Aroxa). Similar in scope and price to FlavorActiv]
Option 2: The Siebel Institute has a couple of flavor kits as well. This next option is also not cheap, but it is based here in the States, so shipping and currency exchange aren’t problems for our US readers. Two sets are available: $180 for 1 vial each of 24 flavors (1L each, same as above), or $180 for 4 vials each of 6 flavors. Dosing is similar to FlavorActiv: open it up, dump it in and mix it. 24 flavors available.
Option 3: Essentially, the grocery store. Cheaper, but more difficult to assemble and many can’t be added to beer. But, we’ve got a shopping list to work from: The ASBC Sensory Committee’s “Additional Flavor Reference Standards”.
- Acetaldehyde (green apple, solvent, paint) – germinating barley
- Acetic (vinegar, sour) – Heinz distilled white vinegar
- Alcohol (fusel, solventy) – Brandy heads (distillation by-products; be careful) 8ml into 355ml
- Astringent – 1% alum / water solution
- Bitter – Sigma-Aldrich Caffeine (FCC) 1g/L
- Brown sugar – C+H brown sugar, 8g into 40ml light beer, mix
- Chlorophenol (antiseptic) – Chloroseptic throat spray, non-flavored
- Citrus – Lemon zest, Langers Ruby Red GF Juice, 0.25g and 6.5ml into 12oz beer, respectively
- Coffee/Roasted – Tully’s Roasted ground coffee, 1.3g into 50ml water, boil, filter, 7ml of filtrate into 12oz beer.
- Diacetyl (butter) – McCormick’s Imitation Butter Flavor
- DMS (corn, canned veggies) – canned creamed corn or black olives
- Ethyl acetate (solvent) – Fingernail polish remover, on cotton ball in jar. Do not add to beer (and drink)!
- Floral/Geraniol – rose petals
- Hoppy – hop tea
- Isoamyl acetate (banana) – Durkee imitation banana flavor
- Isovaleric (cheesy, sweatsock) – Aged hops in jar
- Lemon – McCormick Pure Lemon Extract, lemon zest
- Lightstruck/skunky – Bottled Corona, leave out in sun for awhile (or not, there’s plenty already).
- Lychee – Cho canned lychee, 4ml syrup in 50ml beer
- Malt character – Grapenuts, malt extract (liquid or dry)
- Dark malt / burnt – burnt toast, chocolate malt (extract chocolate malt by steeping 100g in 150ml boiling water, filter)
- Meaty/brothy – Marmite, Vegemite, Knorr’s Beef Bullion
- Meaty/soy sauce – Kikkoman Soy Sauce
- Molasses – Muddy Pond Sorghum
- Onion/garlic – McCormick’s Dehydrated Onion or Garlic Bits
- Orange – Durkee Orange Extract
- Oxidized/aged – Packaged beer, 3 days at 114F or 10 days at 100F (this will likely give papery flavors, especially if it is light beer; find older, colder beer for other oxidized flavors)
- Papery – Wet cardboard
- Eugenol (spicy) – Non-brand whole cloves
- Stale fruit – dampened dried pineapple
- Sulfury – burnt rubber band in jar, Ogilve Home Perm solution (might be hard to find, newer versions have modified aroma)
- Sweet – Splenda, 1packet in 100ml H2O, then 2ml into 12oz beer.
- Vanilla – imitation vanilla flavor
- Vinous/winy – Dry sherry, port
- Vegetable, cooked – Rolling Rock beer (?! – should be lightstruck), cooked cabbage water
- Vegetative – canned green beans and green olives, 10ml bean juice, 5ml olive juice into 12oz beer
- Yeasty – RedStar Active Dry Yeast, 1g into 10ml H2O, set aside for minutes, 8g of mixture into 12oz beer (crown – will foam!), mix.
Option 4: Spike your own. This is what I do at work, but I also use some FlavorActiv capsules since not all flavors are available at Sigma-Aldrich’s Flavors and Fragrances section (or similar departments at Givaudan, Bell Flavor, etc). This isn’t a terribly cheap option, but many of the flavors are offered in “sample” sizes which often go for $40. Most of the time, these are enough to spike well over 1L of beer (already beating FlavorActiv and Siebel’s kits in terms of value), as long as you use as accurate (and small) dosing systems. I use pipettes which allows for very accurate spikes down to single-digit microliters, but if you use an eyedropper and stock solutions (water or ethanol, depending on the solubility of the compound) you could probably do fine without them. Some of these flavors are intensely powerful with low thresholds, so start low and work your way up. Get a hand-crowner from a local homebrew supply store so you can spike into bottles and re-seal them – very handy (with a limited shelf-life, less than a week or so probably, which is still more than the liter you pour out with the first two options). I’ve also created a handy Excel file which calculates spiking amounts with controls for purity, stock solution concentration, and final volume. It works great for me, cutting out a lot of the math.
I realize that some of these options are barely within the budgets of even some small brewers, so there’s not much chance for your average beer drinker to be able to afford more than Option 3. One option is to split the cost between friends; if you have 8-12 friends you could assemble a few times a year for a “training panel” where you pitch in for the flavors and the beer (and maybe the administration responsibilities). You might be able to keep the prices down if you do a few flavors at a time and spread the cost over a number of people.
We’ll go over some of the specifics of the flavors of interest in future posts, but you can probably get enough information by following some of these links and googling a bit until then.
beer sensory science 
Enjoyed reading this, will check back soon!
Other ideas:
Randy Mosher gives ideas for putting together a relatively cheap DIY off-flavors kit in his books “Tasting Beer” and “Radical Brewing.” Likewise, the BJCP Interim Study Guide has similar ideas. In both cases, the spiking chemicals are similar to the ASBC additional references.
The BJCP will send out free Siebel kits to any member who is teaching a registered exam prep session. As of last year, they were also selling kits to members at a discount, but I don’t know if they’re still doing so.
Option 5: There’s a new kid in town. AROXA flavour standards. Made by the same people who manufacture the standards for FlavorActiV but sold direct from their production facility in the UK. Much wider range of products (>250 standards for beer, cider, wine, water and soft drinks), more extensively quality assured; long-life packaging; shipped free anywhere in the world; and competitively priced. FULL disclosure – I’m the Director of the Company so I’m biased, but our website aroxa dot com has a whole bunch of information of use to sensory professionals. Useful even if you make your training samples using options 1 – 4.
That’s interesting news, Bill, thanks.
You mention “more extensively quality assured”. Are you able to elaborate on the differences in quality control between Aroxa and FlavorActiv? One thing I noticed about using the standards from FA is that they tended to be much more intense than the ones that are sent out as part of the Validation System.
I’ve also been curious about the shelf life. At what point do losses in intensity start to become noticeable (assuming properly stored; dark, cool, dry, airtight)?
I understand if you’re hesitant to discuss certain things in such a format, but I thought I’d ask.
For a ‘typical’ flavour standard, such as diacetyl for example, the QA starts with assessing the organoleptic purity and chemical identity of the material we’ve freshly purified in our labs. This is usually done by combined GC-MS-olfactometry – with one of our chemists / tasters on the end of the GC column sniffing the effluent to make sure there’s (i) only one peak; (ii) which smells of diacetyl and (iii) gives a 100% match to the mass spectrum of compound.
We then encapsulate the flavour – generally a specific method for each pure compound (this process typically takes a couple of weeks). After that we check the flavour content of the encapsulate by GC, GC-MS, HPLC or wet chemistry. The material is blended with flavourless and odourless excipients so that the pre-determined amount of the powder in the gelatine capsule or plastic capsulet hits the specification. The final product gets a whole bunch of tests, including blind assessment for odour quality and odour intensity by our taste panel in the target product, microbiological tests, and physical tests (such as bulk density, moisture content etc).
We also do quite extensive SPC testing on the filled capsules, determining fill weights on every tenth capsule filled. Those are plotted against time (Run chart) and by frequency (histogram) to make sure the values are in spec. We make extensive use of HACCP for risk reduction, and a number of Poke Yokes in an effort to eliminate errors. In 15 years we’ve never yet put the wrong flavour in a capsule (hope I’m not tempting fate!) so it seems to work.
We occasionally use ‘A’ ‘not A’ tests to compare different batches of the same standard – and Rank-Rating tests when we’re validating the intensity of materials used in our scaling TVS schemes.
One of our biggest ‘bonus’ QC tests is to check how flavours have performed in terms of their recognition by the 4,500+ tasters in the validation schemes we administer. The slightest drift in concentration of standard can lead to a big change in recognition rate (% correct). If we run duplicate batches in sequential validation ’rounds; – two months apart – they generally agree to within less than 0.5% – the power of the crowd!
Of course, alongside all of this is a level of sniffing of packaging materials, raw materials etc that borders on obsessive-compulsive. We’re generally paranoid about introducing taints into our products so pretty much everyone on our team walks around sniffing the air all the time. If you hand one of our flavours team, a report the first thing they usually do is sniff it rather than read it!
All of the above is managed within our ISO9001:2008 quality system. We also take part in various external proficiency schemes to validate our procedures and analyses.
The gelatine (training) and plastic (validation) capsules are generally exactly the same as one another – we use a different amount of flavour concentrate in each as the capsules and capsulets hold different amounts of powder. However, some are formulated to differ in concentration (an historical thing, due to customer requests) – musty and chlorophenol for example. Maybe it’s those ones you’ve picked up differences on in the past?
In terms of shelf life, most of the standards are pretty bullet proof at room temperature. Our laboratory ‘forcing test’ for stability puts the materials (without the capsule) at 50C for 2 weeks – there should be negligible loss of the encapsulated material. Most of the flavours are good for at least two years, and some for a lot longer. I’ve got prototype materials I made back in 1992 and have been kept at room temperature for almost 20 years which are still fine. There are some though, for example 4-vinyl guaiacol (phenolic), which are less stable and are only good for a year. I’ve seen some folks trying to refrigerate the materials to extend their life. We don’t recommend this. It’s the moisture rather than the temperature that causes the problem, mainly with the gelatine capsules, which go sticky when they get wet, but also to a lesser extent with the ‘host’ encapsulation molecules, which can give up their ‘guests’ when moist.
The losses usually follow pseudo-first-order kinetics – in other words you can plot a log of the residual concentration against time and get a straight line. We’re targeting a loss of no more than 10% at end of shelf life for properly-stored capsules. We do a lot of shelf life testing. We’re always on the look-out for ‘tweaks’ that can improve stability. For example, some encapsulates have greatest stability when you have say four guest molecules inside each host, while others are most stable when the ratio is three or five. We can’t predict which of the options will be better this (so far) – so there’s a lot of empirical testing involved. Some day we’ll figure it out maybe!
With our new AROXA range we’re selling the capsules in packs of 10. This should help in terms of shelf life and stability as they should be used up in half the time that a 20-capsule unit would have lasted.
As you might have gathered, we get a real kick out of this stuff. If you or any of your readers have ideas for new flavours please shout out. We’re always up for a challenge.
Wow, that’s a lot more information than I was expecting. Very enlightening. I have to admit, I’ve been keeping our various capsules in the fridge under the impression it would extend shelf life. Fortunately, we haven’t had any problems with moist capsules. I also just learned recently that the plastic validation capsules can be dispensed by pushing the two halves together to break out the end. I’d been opening them up “proper-like” for quite some time…
Thanks for the info Bill, and good luck with your new endeavor!
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