My thanks to the contributors and to John Kleinchester for help with photos.
A few weeks back, an entrepreneur (in this case a modern-day version of a snake oil salesperson) who calls herself the Food Babe used her website to malign the brewing industry.
She accused brewers of employing a host of “shocking” ingredients: GMOs! Beaver anal glands! Corn syrup! GMO corn syrup! Carcinogenic caramel coloring! Etc.
She claimed to have conducted a substantive “investigation” into beer ingredients and when breweries declined to confirm/deny, concluded that beermakers had something to hide.
Worse — as it if could be worse — many in the craft brewing community spread her tale via Twitter and Facebook.
I’m not a beermaker and have zero science background (alas) but even I could tell that her claims and charges were nonsense.
Bare minimum, this one fact set off my alarm bells: She relied on information from the Center for Science in the Public Interest. If you’ve read Ambitious Brew, you know that I have zero patience with CSPI. For thirty years, that group has railed against the alcohol industry and lobbied for neo-prohibition. As a source of information, it’s untrustworthy, unreliable, and constantly shows a somewhat shocking disregard for science (weird, given the group’s name).
So why should I bother with her nonsense?
First, as many of you know, I’ve spent the past seven years writing a history of meat in America. Thanks to that project, I’m tuned into the “food debate” ongoing here in the United States and elsewhere. And what I can tell you is that a) the food “debate” is mostly a shouting match; and b) much of the information being tossed around is inaccurate (often intentionally so in order to score points).
But I’ve also learned that this kind of “discussion” is extraordinarily counter-productive and, frankly, even dangerous: When big groups like Greenpeace, for example, use lies to gain ground, we’re all damaged. Misinformation creates paranoia and fear.
So, yeah, bugs the hell out of me to see stuff like the Food Babe writes.
Second, and because of my awareness of the food debate, as soon as I read the Food Babe’s screed, I thought
“Oh, man. I can see it coming: Some brewers might decide to use this kind of crap to score points with consumers and one-up their competition. Result: a purity war erupting in the craft brewing industry. Nothing good can come of this.”
Especially because, as I noted above, people who should have known better spread the Food Babe’s crap as if it was gospel.
So, meddlesome broad that I am, I reached out to some brewers, both professional and amateur, and asked if they’d help set the record straight. No surprise, given the kind hearts and generosity that are the hallmarks of craft brewing, I got an immediate response. Much of what follows are their responses to the question “What’s in Your Beer.”
But before I turn it over to them, allow me a few words about genetically modified organisms, or GMOs.
Many people who preach a GMO gospel, either for or against, base their view less on fact than on ideology. GMO haters are particularly vociferous and, alas, sadly ignorant of basic facts about this technology. Worse, many organizations, both non- and for-profit, cater to nonsense and misinformation as a way to promote their causes/industries.
Why do I know this? Because about six months ago, I decided to educate myself on the subject of genetic modification — and promptly fell into the house of mirrors that passes for “information” on GMOs.
Weeks of digging and reading ensued, but eventually I found websites and organizations that dispense sound, factual information (and so was able, finally, to form an opinion based on substance rather than deceit).
I encourage all of you to do the same, but I’ll spare you my lengthy search: If you’re interested in learning about GMOs from informed, honest, accurate sources, I recommend these two websites:
I also recommend Nathanael Johnson, the new science writer at Grist, an online environmental magazine. Until recently, Grist ran the usual nonsense crap about GMOs. But this summer, Grist hired Johnson and he launched a series looking at the GMO discussion in an objective manner.
His work is first rate and I recommend all his posts. The first one is here. But if you visit page at Grist, you’ll find other parts of the series (just scroll down), as well as a recommended/not recommended reading list. (And, no, Smith’s Seeds of Deception does not make his recommended list. That book is total bullshit.)
So that’s my take on GMOs. (I note here that my contributors to this post begged off on dealing with GMOs because, they told me, they weren’t knowledgable enough to comment on them. I appreciate their candor. Would that others were equally honest about their ignorance; better than than a rush to judgement.)
With that, I turn this over to skilled brewers who want to help you, the consumer, navigate the Food Babe’s ignorant contribution to the food debate. Read as much or as little as you want (the contributors cover different parts of the terrain.) And as always: Thanks for reading. (And if you like what you read, please tell your friends.)
Mitch Steele is the Brewmaster for Stone Brewing Co. Since graduating from UC Davis in 1984 with a Fermentation Science degree, he has brewed at some of the largest and smallest breweries in the world.
After starting his brewing career in 1988 on a 14 bbl system at the San Andreas Brewing Co. in California, Mitch joined Anheuser-Busch in 1992, managing Brewhouse and Fermenting operations in 3 different breweries, and developing new beers as part of the Anheuser-Busch Specialty Brewing Group in the mid 1990s.
Mitch joined Stone Brewing Co. in 2006 and has managed the brewing and packaging operations at Stone as the company has grown from a 48,000 bbl operation to 175,000 bbls in 2012. He is the author of IPA: Brewing Techniques, Recipes and the Evolution of India Pale Ale.
Mitch’s response to the Food Babe:
In her piece, the Food Babe wrote:
“Ingredient labeling on food products and non-alcoholic beverages is required by the Food and Drug Administration. But a whole other federal agency regulates beer, and not very well. The Department of Treasury – the same folks who collect your taxes – oversees alcoholic beverages. That probably explains why we know more about what’s in a can of Coke than a can of Bud. You can also thank the alcohol industry, which has lobbied for years against efforts to require ingredient labeling.”
All alcoholic beverages are monitored by the TTB, the Tax and Trade Bureau, formerly an agency within Bureau of Alcohol, Tobacco and Firearms. TTB has strict rules regarding beer ingredients. Any beer made with “non-traditional” ingredients, mean anything other than malt, water, yeast and hops (as well as some adjuncts) must go through a strict formulation approval by the TTB before the beer can be brewed.
So the insinuation that brewers can put anything in their beer and not label it is false and absurd. There is government authority on what brewers can use in their beers. And I can say that the FDA IS involved with brewing at an increasing rate.
The Center of Science and Public interest is a well-known Neo-Prohibitionist organization, so any publication from them has to be taken with a grain of salt. Their stated goal is to eliminate alcoholic beverages and adult drinking. As such, their list can hardly be considered objective.
Taking the ingredient list one-by one, and basing my comments on 25+ years in the industry, working for small and large craft brewers and for many years at Anheuser-Busch:
1. MSG: Never heard of anyone using this in beer. [Maureen’s note: for a recent superb look at MSG, see this piece by John Mahoney.]
2. Propylene Glycol is a food grade substance used for external chilling systems in most breweries. It is a better, safer cooling agent than Ethylene Glycol, which is highly toxic. The only way propylene glycol could get into beer is by a leak in the cooling system. When I was at Anheuser-Busch, we tested our beers regularly to ensure that it was glycol-free. We also sampled and checked every glycol jacketed tank annually. I have heard of some beverages where small amounts glycol were added to add body or flavor, but I have not heard of this being done in beer.
3. Calcium DiSodium EDTA: Not sure what this is or why anyone would add it to beer
4. Sulfite preservatives are generally not added to beer. Ironically, the Food Babe’s website features a photo of her drinking wine, one of the most heavily sulfated beverages in the world. Sulfur is applied to grapes and to wine at many stages throughout the winemaking process.
The TTB requires sulfur labeling at levels over 10 ppm. Yeast generally produce 3-5 ppm sulfite naturally during fermentation, so adding sulfite as a preservative is what will take you over 10 ppm. No brewery in the United States uses sulfites in beer. The practice is rare worldwide, and the beer would have to be labeled as “contains sulfites” if sold in the US.
5. Dextrose and Corn Syrups are used primarily by big brewers usually to lighten flavor, and in some cases to reduce production costs. Dextrose powder is a common ingredient in craft brewed double IPAs. In England, most ales are made with the addition of brewing sugars (which contribute flavor and fermentable sugar), and have been made that way for well over 100 years. Most Belgian Trappist beers are brewed with a portion of candi-sugar syrup. Brewers use corn, rice or sugars because the sugars are almost 100% fermented by yeast. Consumers are not drinking “corn syrup.”
The use of “adjuncts,” such as rice or corn began in the United States in the 1800s because American malt was of suspect quality and sometimes resulted in harsh, heavy beer. At the time, big brewers were located in the midwest —St. Louis, Milwaukee, Cincinnati — where the summers are brutally hot. American consumers wanted a lighter, more refreshing beer. Brewers added adjuncts to compensate for the kinds of barley/malt they had access to.
6. Dyes: I know of no brewer using dyes in their beer. Doesn’t mean that it doesn’t happen, but I suspect it is very rare, if at all.
7. Caramel coloring: Primarily used by English brewers, though it’s possible that some “dark” versions of mainstream beers include some kind of caramel coloring —though you don’t see those beers anymore. Michelob Dark, made by AB, got its color from black malt, not food coloring or caramel coloring. I can’t verify her claim that Newcastle’s caramel coloring is highly toxic. She would need to say exactly what they use to substantiate that claim.
8. Isinglass and gelatin have been used for well over 100 years in beer (and in wine) as clarifying agents. These compounds attract solid material in the beer, which then clump together and sink to the bottom of the tank, leaving the remaining beer crystal clear.
Carageenen, made from natural seaweed, performs a similar function to the Isinglass and Gelatin: It’s added in the brewhouse to help get solid proteins to settle out of the wort. Again, it does not remain in the wort, or in the beer.
The key point, however, is that this material stays behind in the tank. It’s not in the final beer product. English brewers commonly use these clarifying agents. Most American brewers use synthetic versions that do the same thing. In both cases, the clarifiants are not present in the final product.
9. Natural Flavors: Many fruit beers are made with natural flavors. That’s the only way to get certain flavors to the desired level in some beers. I don’t think this is necessarily a bad thing. But the process would require TTB approval, and I know for a fact that they do a ton of due diligence on any natural flavor that is being proposed.
10. Foam Control: Some big brewers who use more adjuncts (eg, corn, rice) than hops use foam stabilizers. Beer foam is primarily made up from proteins from the malt and tannins from the hops. Reducing the amount of malt or hops in a beer can make the foam head appear weak. Again, anything added to beer is subject to formula approval and scrutiny from the TTB.
Todd Parker has brewed professionally for 14 years (and homebrewed for 24 years) in California, Wisconsin, Michigan, and Virginia, working in brewpubs and medium-sized microbreweries. He has a bachelor’s and a master’s degree in biology.
Todd’s response to the Food Babe:
Information about our food is a vital concern, however demagogery and muddying the waters with unsubstantiated claims and statements like X can be made with poisonous X (even though it can be made safely and non toxicly other ways) does not further the discussion and damages the conversation.
We are craftsmen who take pride in our products and would never take a shortcut that might jeopardize the quality of our products.
So for consumers’ edification, we craft brewers use this, and why:
Water: obviously, and we might add items like gypsum or chalk to it to replicate the water character of different regions
Carbohydrates — materials that yeast converts to alcohol: mainly malted barley, but we might use smaller quantities of other grains as flavorings, including wheat, rye, oats, tef, buckwheat, quinoa, spelt, rice, wild rice, amaranth, triticale, kamut, or corn.
Brewers also use other sugars: molasses, honey, candi sugar, piloncilo, jaggery, maple syrup, or date, beet or palm sugars, and even fruits and vegetables. Such sugars make up only a small portion of our carb sources and flavorings. Some brewers might use high fructose corn syrup to lighten the body of their beer, but it’s not a common ingredient.
While we cannot guarantee that nobody uses GMO products, they are not generally available to the majority of brewers. Most craft brewers are against their use and will never use them.
Herbs/spices/flavorings: hops are the main herb used. [Some brewers use] various spices like coriander, cinnamon, ginger, mace, nutmeg, chiles, vanilla, coffee, woods, flowers. They are not common ingredients, but may be used to create unique flavors. Also fruits and vegetables can be used. While some may use artificial flavors, most likely the market can taste it and it will not be very successful.
Microorganisms (convert carbs to CO2 and alcohol): While there are two main types of yeasts used, ale and lager yeasts, a handful of brewers use wild yeasts and bacteria. No human pathogens grow in beer: alcohol and pH inhibit their growth.
Other Aids/Process Chemicals:
** Dyes are not commonly used, although some will use a legal dark food coloring called Sinamar [made from roasted malt] to make Black IPAs.
**EDTA: never heard of its use in beer.
**Sulfites and Preservatives: not common in the industry. Many breweries have some form of date code on their beer to ensure its freshness.
**Finings (designed to precipitate out charged particles):
Carageenan aka Irish Moss: this is a seaweed added to the kettle to help precipitate out charged particles. Through stable isotope studies, it does not leave the kettle with the wort, it settles out with the precipitated particles. It is even allowed in Germanys Rheinheitsgebot. It is very common to use.
Isinglass (fish swim bladder protein): a traditional English ingredient that is not used as much anymore because of better products available as well as concerns with vegans. It pretty much stays in the fermenter and does not leave with the beer.
PVPP, Silica gel: expensive, but used as a fining and as a filter aid that gets strained out in the filter. More common in bigger breweries.
Diatomaceous Earth: the fossilized remains of single celled algae. It is either embedded in filter pads or as a powder that is used on a filter. The dust is a carcinogen, but it is hydrated for use in the filter and stays in the filter after the clear beer leaves. Perlite is a volcanic soil used like DE, but less hazardous as a dust.
For a comprehensive look at the ingredients craft brewers use, visit Brewers Supply Group and click the link for its 2013 Resource Guide, or visit Country Malt Group and check out the list of ingredients and supplies that company offers.
Michael Copado, known as “revvy” on the popular beer forum homebrewtalk, is an avid and award winning homebrewer, as well as a student of brewing history. His online recipes are some of the most popular brewed on the forum.
Michael’s response to the Food Babe:
Sugar is fundamental to the process of making beer: The beer’s yeast feeds on the sugar and converts it to alcohol. Put another way, it’s incorrect that beer contains “corn syrup.” Thanks to hungry yeast, that syrup and other sugars are gone by the time you enjoy your beer.
That’s an odd concept to grasp: When we drink an alcoholic beverage, we’re not necessarily drinking the ingredients used to brew the beer. Rather, the finished product contains sugars converted into alcohol by the yeast.
Brewers typically use three types of sugars used in the brewing process; complex, simple, and non-fermentable. Most beers contain some combination of all three; that combination provides beer styles with their distinctive flavors and “feels.”
Complex sugars are the most difficult for the yeast to convert into alcohol. Most complex sugars come from the grains used to make beer, such as barley or wheat. During the mashing process, malted grains are soaked in warm to hot water to allow the tiny starch granules in each cracked kernel to convert to sugar.
Brewers also use simple sugars, which yeast converts quickly and easily to pure alcohol. Simple sugars contribute to alcohol content without making a thicker, heavier beer. The higher the percentage of simple sugars, the more drinkable a beer will seem.
Sometimes brewers use unfermentable sugars, the most common being lactose (milk sugar), which gives beer a creamy mouthfeel and a slightly sweet taste. Lactose is a common addition to milk stouts (as opposed dry stouts, such as Guinness.) “Chocolate” and “cream” stouts are typically made using lactose. Most home brewers (and probably many commercial ones) add it during the boil (which insures the lactose powder is sterile) but it may also be added during the bottling process.
The less fermentable or unfermentable sugars contribute to the final taste/finish of the beer, affecting its “body” (a perceived heaviness to the beer), mouth-feel (thickness on the tongue and throat as you swallow it), and flavor. (Regardless of what kind of sugars are used, all drinking alcohol, or ethanol [ETOH], has the same chemical formula, CH3CH2OH.)
The best way to understand the role sugar plays in the brewing process is by comparing two different beer styles of similar alcoholic “strength.”
For example, do a comparison tasting of Sierra Nevada’s Big Foot Barleywine, and Green Flash Brewing’s Tripel (or two other styles with identical alcohol content).
Both beers clock in at 9.6% alcohol by volume. But the barleywine seems heavy and full compared to the tripel, which seems smoother and more “drinkable.” (In fact, a triple can be a “sneaky drunk” amongst beer fans: it’s as smooth and easy to drink as a lager or pale ale but contains nearly twice the punch.)
Both beers are “high gravity”: they’re made with complex and simple sugars; those contribute to their high alcohol content by volume. In barley wine, most of the sugars come from grain. In a tripel, however, up to thirty percent of the fermentable ingredients come from simple sugars.
Try the same experiment with your favorite domestic lager, such as Budweiser, and a craft brewery’s pale ale. Budweiser has an abv of about 5%, but it has a lighter body than the pale ale because it’s made using rice syrup. (Rice and corn syrups are called “adjuncts,” a brewing term for something other than grain added to the beer.)
Brewers use different combinations of grain, time, and temperature to create beers with different bodies, different alcohol content, and ultimately different flavors. Some beers will be drier, and some will be sweeter.
But the important point is this: Yeast eats those sugars and converts them to alcohol. Your beer doesn’t contain corn syrup.
For information on the long-time use of finings as a preservative, see this this example from a BBC source about life in World War II:
” Mother used to put eggs down in Isinglass, a preservative solution, in large crocks when eggs were plentiful. They didn’t have the flavour of fresh eggs but were very useful for cooking. And of course there were dried eggs useful for cooking – some good cooks claimed they could make a decent omelette with dried egg.”
Here’s a video presentation of the use of isinglass. Fast forward to 5:25.
Steve Parkes is the owner and lead instructor at the American Brewers Guild Brewing School. Steve graduated over 30 years ago with a degree in Brewing Science from Heriot-Watt University in Edinburgh Scotland and has been brewing ever since. With his wife he owns the nation’s premier brewing school for craft brewers as well as Drop-In Brewing Company in Middlebury Vermont.
He has built breweries in England and America, and consulted on numerous brewery projects here and overseas. He has held officer positions with the Brewers Association (BA) and the Master Brewers Association of the Americas (MBAA). He wrote the chapter on Brewhouse practices for the Handbook for the Specialty Brewer published by the MBAA, and contributed several entries to the Oxford Companion to Beer. In 2009 he won the Russell Schehrer Award For Innovation in Craft Brewing presented by the Brewers Association.
Steve’s response to the Food Babe:
Propylene glycol is a food additive that manufacturers use mainly as a sweetener that cannot ferment. Back in the 80s some Austrian wine makers were caught adding it to wine as a sweetener to try and mimic the more expensive late harvest German wines. It’s use to make both Mountain Dew and Cream Soda.
Brewers, however, use it primarily as a food grade refrigerant. Why is it on the list of approved ingredients? Every production process aid is listed regardless of whether it’s in the final product or not.
Beaver anal gland, aka Castoreum. Castoreum is used to mimic the flavor of vanilla, and raspberry and legal to use as a “Natural Flavoring.” It’s unlikely that many or any brewers use Castoreum. Only 300lb is used annually (harvested from dead beavers). Much of it is used to manufacture perfume. If the Food Babe uses Chanel, Lancomme and Givenchy, she’s probably dabbing beaver anal gland extract behind her ears daily. Castoreum itself is not specifically listed on the TTB’s list of approved ingredients; instead it’s a “natural” flavoring that can be added to beer.
The problem lies in the TTB labeling requirements. If a brewer makes a raspberry beer using natural flavoring, her label must read “Ale Brewed with Natural Flavorings.”
Nathan Heck has 18 years of professional brewing experience in a variety of settings from brewpubs to large regional breweries, and devoted a year trying to start his own brewery in Massachusetts. He most recently worked for Harpoon Brewery and is now exploring new career opportunities. Nathan earned a certificate in brewing technology from the Siebel Institute in 1995 and his MBA from Northeastern University in 2003.
Nate’s response to the Food Babe:
The Food Babe’s list of “acceptable” ingredients is misleading for a couple reasons. She presents these substances as if they are frequently used by brewers, and because she couldn’t obtain full ingredient lists from the breweries she spoke to, she implies that there is some sort of cover-up going on.
**Monosodium glutamate, the much maligned and feared food additive. Much of that fear is unjustified. Both the FDA and the AMA have determined MSG to be safe for consumption.
More important, glutamates occur naturally in foods that I’m sure the Food Babe would wholeheartedly endorse that we eat more of, like tomatoes and mushrooms.
But glutamates occur naturally in yeast and as a byproduct of beer fermentation. Beer “can contain” MSG because glutamate occurs naturally in its production: glutamate combines in small amounts with sodium ions present in wort and fermented beer, and not because evil-doing brewers are adding it.
In all of my years making and fermenting wort, I have never added MSG to any of the products I have made.
** Bisphenol-A, or BPA: Laboratory studies have indicated that this can be an endocrine disrupter and have some other deleterious health effects.
Human beings, however, are not mice and the European Food Safety Authority has found that humans metabolize BPA differently than our four-legged counterparts and in a way that counters BPA’s ability to mimic estrogen. Studies have shown that BPA is potentially harmful to developing fetuses and very small children. That’s why it is no longer used in the manufacturing of baby bottles and things like sippy cups.
Brewers are aware of the controversy surrounding BPA. But does it warrant a place on the Food Babe’s list when it is used to make things like grocery receipt paper? No. The leaching that she worries about has been shown to be minimal. According to New Belgium Brewing Company’s blog:
“The amount of BPA migrating from can coatings would result in the consumption of less than 0.105 micrograms (0.000105 milligrams) per kilogram body weight per day. This level is more than 475 times lower than the maximum acceptable or ‘reference’ dose for BPA of 0.05 milligrams per kilogram body weight per day, which was determined to be the safe life-time exposure dose by the USEPA in 1993.”
It should also be noted that the primary source of BPA leaching comes from heating and re-heating the plastic, and time. Beer is packaged cold, stored near room temperature at its warmest and is typically consumed within a few weeks to a couple months of packaging, hardly enough time for significant BPA pick-up.
Finally, an important distinction: The Food Babe implies that brewers are adding BPA to the beer somewhere in the brewing process and are trying to conceal its use. This is not true. Brewers like New Belgium and Sly Fox are very aware of their consumers’ concerns about BPA and are working with packaging manufacturers to come up with some type of BPA-free can.
Eric A.C. Sorensen is a Regional Brewmaster in the Midwest with Rock Bottom Restaurants & Breweries at West Des Moines, IA . He has more than two decades of experience in beverage production. Originally educated as a Social Anthropologist and Linguist at UCSD with graduate work at the University of Virginia, he added courses in brewing, viticulture & enology at UC Davis.
He studied brewery engineering, quality control & analysis, sensory evaluation, and microbiology at the Siebel Institute of Technology while working at Mad River Brewing in the brewhouse and cellars. As an apprentice brewer at Lost Coast Brewery & Café in Eureka, CA, he quickly advanced to Lead Brewer. With his wife he founded a winery that produced a variety of fermented beverages under the Golden Angels Cellars, Galvey & Clarke and Humboldt Cider Co. labels. According to Julia Herz, the winery was ahead of its time and an inspiration to mead and cider makers who followed in the Sorensens’ footsteps.
Finings, filtration and Flavor
For centuries, beer makers have used “finings,” as they’re called, to remove yeast and protein hazes that occur in fermented beverages. These clarifying materials do not carry over into the beer in any appreciable amount, so no one but the most militant vegan can protest their use. Nowadays, some brewers prefer the complexity and character of unfiltered beers, because filtration can strip out more than just protein and yeast. But finings offer a way to create clear brews preferred by many consumers.
One common fining material is isinglass, which is made from the swim bladders of tropical fish. Yeast cell walls carry a negative charge but isinglass is positively charged. The difference in the electrical charges allows the yeast to settle to the bottom of the brewery’s tanks or the casks from which it is served. Gelatin finings achieve the same purpose, and winemakers use egg whites to settle yeast.
Auxiliary finings may be used in the kettle or tank to remove proteins from the beer through the opposite interaction. Carrageeenan, somtimes known as Irish moss, is a an edible seaweed used in the wort copper to allow protein to precipitate later in the tank. Boiling the wort coagulates some of the grain proteins and they can be removed in the kettle or whirlpool along with the hops, but others are more complex and may require alginates extracted from other types of seaweed or bacteria. (Carrageenan is also used in making ice cream.) Finings and auxiliary finings cannot be added together or they lose their effectiveness.
Some brewers use finings while making cask beer; cask beer re-ferments in the firkin or pin and the yeast needs to be settled quickly so it can be served fresh. Good cellarmanship demands the cask be decanted so that the “bottoms” (yeast and protein) are left behind and don’t get in the way of a good pint.
Rock Bottom Breweries are on the vegan watch list because we sometimes use isinglass. Some of our brewers use a product called Alginex before filtering so they don’t have to use as much diatomaceous earth (more on DE later). A well-made and lagered or aged beer will drop “bright,” but many brewpubs don’t have the time or tank space for such luxuries.
Strip it out
Filtration is a mechanical method of clarifying liquids in general and beverages in particular.
Sheet, plate, and frame filters are widely used in the craft beer industry. Sheets are paper embedded with keiselgur or diatomaceous earth (DE), a powdery mineral that is the fossilized remains of diatoms, a variety of marine algae. DE, graded by size and porosity, is used to filter different materials from the beer.
DE is also be used in lenticular, candle, and plate filters of various configurations to remove yeast and proteins from the beer. The downside to using this is disposal. It can be a carcinogenic health hazard if inhaled. It’s also sharp, even at a microscopic level. (You wouldn’t believe what DE looks like under a microscope.)
Another graded earth, perlite, which is volcanic, is also used as a filter aid. Like DE it is porous, but less prickly than DE. Some versions have a flavor all their own which can pass into the beer or wine.
Cross-flow or ultra filters are also gaining use in brewing: cartridges with a cluster of porous spaghetti-looking tubes embedded in them. Turbid beer is pumped through the cartridge and clarified beer passes through the walls of the tubes while the flow keeps the surface from blinding and it is recirculated back into the product tank. The unfiltered beer is continuously pushed through the cartridges until only protein and yeast are left behind. But because filtration can remove desirable flavor compounds from the beer, breweries who can afford to do so have switched to centrifuges.
Glycol in beer?
Glycol as ethyl or propylene is a common anti-freeze and as propylene, is used in the refrigeration systems of many small breweries. Glycol, whose freezing point is lower than water or beer, is employed as a circulating refrigerant to maintain tank jackets at the proper temperature. Attemperating the glycol in the refrigeration system is done via a compressor running Freon through air cooled coils or sometimes ice banks or water towers. Larger breweries tend to use ammonia as their refrigerant of choice.
But that glycol only ends up in the beer if a tank leaks. That’s an engineering problem. As part of our troubleshooting section in brewing school, we studied the example of a beer whose gravity increased after finishing fermentation. Propylene glycol is more concentrated than most wort or beer and tastes sweet. (I’ve gotten a mouthful fixing a refrigeration line and I don’t recommend drinking it, but it is an ingredient in many intimate lubricants.)
There is an ingredient used in making some beers that contains glycol. Grant Johnston was working on making a fruit beer that could be made quickly for the brewpub in Marin, CA. Grant asked a local company, Mane California Brands, which makes natural fruit flavoring, to design a series of concentrated fruit flavors that could be added to his Grundy tanks a gallon at a time. California Brands uses glycol as a carrier for the flavorings since alcohol added in those amounts would be against ATF (now TTB) rules. Personally I prefer using juice concentrate if I am not going to use fresh fruit, but at least one brewery I have worked for still uses natural fruit flavoring.
Thanks for reading, friends! Namaste.