Gluten test: can you detect gluten in beer?

In this follow up to Gluten Free Beer: The Basics, I look into gluten test methods and their validity. Is that beer really gluten free? Find out!Updated May 12, 2016

Last month, I told you how gluten free beer is made, and explained the differences between naturally gluten free and gluten removed beers. In response to one of my tweets promoting that article, I received the following message:

Margaret Clegg on Twitter

@GFFabLife I don’t trust gluten removed beers. Here’s an explanation as to why. @NimaSensor …

The article Margaret shared (from Nima Gluten Sensor’s website) explains that traditional gluten test methods are looking for a whole protein. Gluten removed beers are shattering this protein to bits, making it difficult to detect. To explore this further, we need to first understand how testing works. Then we will take a look at these shattered proteins and what’s known about them. Finally, we’ll look at how testing is considered reliable (or unreliable) in the United States and United Kingdom.

The TL;DR version of the story: there are a few ways to test for gluten in food that work pretty consistently. However, when you test fermented or hydrolyzed foods or drinks, they don’t work so well. This is because the gluten has been processed, changed and broken into fragments – the tests can’t pick up the fragments. There’s no universally accepted means of testing for gluten in fermented drinks like beer. No one is really sure if the fragments are safe for celiacs or not, and no one is really sure how much gluten or gluten derivatives are really floating around in a gluten-removed beer.

Now, if you’re curious about the science in all of this, read on! If not, just skip down to the conclusion and talk to me in the comments!

Gluten tests

There are three basic ways gluten can be detected in foods. The most common type of gluten test uses enzymes to detect gluten proteins. Specifically, these tests for gluten in food products are known as enzyme-linked immunosorbent assays (ELISAs). This is commonly accepted as the best way to detect gluten in food. Mass spectrometry is a less common method of detecting gluten. It works by measuring atoms and molecules, using this information to identify the ‘species’. Finally, the polymerase chain reaction (PCR) method has been used to detect gluten from wheat, but doesn’t seem to work with barley, rye or other gluten-containing grains.

ELISA R5 Sandwich

This enzyme gluten test is reliable for detecting gluten in food items. It uses two antibodies to “sandwich” a molecule for measurement. However, it is “notoriously unreliable for detecting hydrolyzed gluten.The fermentation process hydrolyzes gluten in beer, so this test cannot accurately measure gluten content in beer.

ELISA R5 Competitive

This gluten test only uses one antibody, and “has greater precision, accuracy, and reproducibility.” However, it has “lower overall sensitivity” than the Sandwich test. The competitive R5 ELISA is the standard test used to detect hydrolyzed gluten, or fragmented gluten proteins in beer. “Many published studies have found the competitive R5 ELISA to be a reliable indicator of hydrolyzed gluten,” according to As an example, this study from Spain supports that assertion. The American Association of Cereal Chemists International (AACCI) did a collaborative study in 2013, following which they declared the R5 Competitive testing method to be “valid for testing fermented foods and beverages.”

Mass spectrometry

There have been a few studies in Australia which have claimed that mass spectrometry is more accurate than the ELISA R5 sandwich test. This study tested 60 beers with both methods and found mass spectrometry to be more reliable for detecting gluten. Another study subsequently found that the ELISA method gave false negatives when dealing with certain fragmented gluten proteins. However, mass spectrometry is not commercially available (as of this writing), so it’s not commonly used as a gluten test. Neither the ELISA R5 nor mass spectrometry have been officially or widely accepted as valid methods for detecting gluten in fermented or hydrolyzed foods and drinks.

What is hydrolyzed gluten and is it safe?

We know that fermentation hydrolyzes gluten in beer, but what does that mean, exactly? Hydrolysis is “a chemical process of decomposition” which changes the chemistry of the affected molecules. Nima Sensor has a good explanation of how this works in beer, but I’m going to give it a shot.

In really basic terms, think of a gluten protein as a shoelace. Fermentation turns the shoelace into yarn. Then, when the beer is treated with enzymes to break down the gluten, the yarn is hacked into lots of small pieces. Enzyme tests like ELISA (which is what the NIMA Sensor uses) require enough space on the shoelace to grab on – when they are presented with tiny bits of yarn, the enzymes can’t find enough space to latch on. They will show that they didn’t detect any gluten, when really, there’s little bits of chemically modified gluten floating about!

But is it safe? A very small Italian study found that fully hydrolyzed wheat was well-tolerated by celiacs. This wheat contained gluten at 8 parts per million. That’s really the only place I found any research-based evidence for or against hydrolyzed wheat.

Gluten Free Dietician magazine said in 2013 the ELISA test will detect one particular amino acid which points to the presence of gluten in beer. But, author Tricia Thompson says, “this does not mean the beer is free of other toxic peptides” even when the test fails to detect that amino acid. Oregon Live reported in 2013 that “scientists say the test doesn’t detect all potentially harmful gluten fragments. Recent tests by Canada’s public health agency found gluten fragments in beers from Spain and Belgium that use a gluten-removal process” similar to the one used by Omission Beer, a well-known gluten-removed barley beer in the United States. In that story, they interview Stephen Taylor, co-director of the University of Nebraska’s food allergy research and resource program. Dr. Taylor notes his concern that there might be “big pieces of gluten protein left in this beer that are still potentially hazardous.” He goes on to ask, “does it make the beer safe for people with celiac disease? The answer to that is nobody knows.”

You’ll find hydrolyzed wheat on many “Do Not Eat” lists on gluten free websites across the internet, including Gluten Free Living and Celiac Syndrome. Popular opinion certainly seems to indicate an unwillingness to trust hydrolyzed wheat and barley. Erica from Celiac and the Beast rolled back her initial recommendation of Omission after learning more about the unreliable test methods used to determine the beer was “gluten free.”

What the law says – United States and United Kingdom

The US Food and Drug Administration has proposed an update to the Gluten Free Labeling Final Rule (2013) that would specifically govern hydrolyzed, fermented and distilled foods:

Hydrolyzed, fermented, or distilled foods voluntarily bearing the “gluten-free” claim will also still have to meet the requirements of the gluten-free food labeling final rule, including the definition of “gluten-free,” which means that they are either inherently gluten-free or they do not include any of the following:

  • Ingredients that are gluten-containing grain
  • Ingredients derived from a gluten-containing grain that have not been processed to remove gluten
  • Ingredients derived from a gluten-containing grain that have been processed to remove gluten if use of that ingredient results in the presence of 20 parts per million (ppm) or more gluten in the food

Source: Food and Drug Administration

They also acknowledge the lack of reliable testing methods for fermented and hydrolyzed foods, noting “as of November 18, 2015, we are not aware of any methods for which there is an appropriate reference standard to gauge the response for detection and quantification, with precision, of the gluten content in terms of intact gluten in fermented and hydrolyzed foods.” This was a full two years after the AACCI’s 2013 study which declared ELISA R5 Competitive to be valid for fermented foods and beverages. It would appear the FDA disagrees.

Essentially, what the FDA is proposing means that gluten removed beer still won’t qualify for gluten free labeling, because the gluten is being removed during fermentation and the testing methods are too unreliable to trust. However, beer brewed from gluten-removed grain, like Kebari barley, seems to fit the proposed rules and would potentially be labeled gluten free in the United States, assuming the proposed rule becomes final.

Ingredient information in the United States versus United Kingdom

Compare that to the policy in the UK, where there is no requirement for gluten testing, and their best practices state:

Food businesses producing pre-packed and non pre-packed foods need to ensure that any “gluten-free‟ or “very low gluten‟ claims that they make are justified, and this requires some analytical testing.

Source: Food Standards Agency

Further, instead of recommending a test, they state:

The Commission Regulation does not specify a particular test method to determine the level of gluten in the final food. This is to allow for the possibility of technical advances in analytical methodology. The Commission Regulation refers to the Codex Standard for Foods for Special Dietary Use for Persons Intolerant to Gluten, which was agreed in July 2008. Within this Standard it states that the level of gluten should be determined using the Enzyme-linked Immunoassay (ELISA) R5 Mendez Method.

Source: Food Standards Agency

In case that wasn’t clear, the UK is recommending ELISA R5 sandwich testing. These regulations appear to be specific to food and no mention of beer was found. They do say in several places that specific regulations are up to the local authority. (A local authority is kind of like a cross between a state and a county in the United States – they are local governments who have representation in the national government, but still have some governing authority in their region. Most local authorities are geographically similar to a county – for example, Glasgow City is one of Scotland’s local authorities.)

As these regulations don’t really seem specific to beer, I checked around with some international brewers who sell beer labeled “gluten free” in the United Kingdom to see which test they are actually using. Bellfield Brewery is using ELISA R5 competitive. Celia and Ocho Reales are both using ELISA tests, though it’s not clear which one. Daura Damm and ^Green’s both say they are testing as gluten free but haven’t published their test methodology or results.

I’ve reached out to a couple of labs that do gluten testing to find out exactly what methods they are using. However, it seems that this is pretty loosely regulated in the UK, and as such, I am now actively avoiding gluten-removed beers here. At best, they are relying on the ELISA R5 competitive method for testing, which we now know is problematic.

^UPDATE May 12, 2016: After publishing this article, I received an email from David Ware, owner and director of Green’s Beers. He noted that they have published their gluten test results on their website (click through to Our Beers, then “See Our Beers” at the bottom, then select the beer you’re interested in.) He also noted they are using ELISA R5 competitive testing.

He said something else I found very interesting, and has given me permission to quote him.

Most of our business is conducted in the USA and Canada, despite being a UK company… We produced the first ever gluten free beers in Europe back in 2003… from gluten free grains [like] sorghum, millet, buckwheat and brown rice. We still sell these beers, and export them extensively to every US state. In Europe they are less popular against the burgeoning choice of cheaper deglutenised beers. We joined in with our range of deglutenised beers in 2009, and they have taken up the bulk of our European sales to date.

-David Ware, Owner and Director, Green’s Beers

So if you’re buying Green’s in the US and it is labeled gluten free, you’re good. If you’re buying it in the UK, you need to read the labels to find out which beer you’ve picked up, as it could be gluten-removed. You can also buy directly from their website.^


In this follow up to Gluten Free Beer: The Basics, I look into gluten test methods and their validity. Is that beer really gluten free? Find out!

Naturally gluten free beer only! Photo: Beer via photopin (license)

While the brewers of gluten-removed beers continue to claim that their beers are safe for celiacs, I have yet to find clear and convincing evidence to support this. Gluten removed beer relies on ELISA testing, which has not been widely accepted as valid, nor has it proven to be entirely accurate. Mass spectrometry looks promising, but isn’t widely available.

Until it can be conclusively shown that either the gluten is being reduced beyond dangerous levels in beer, or that gluten protein fragments aren’t harmful, I will be passing on gluten removed beers. I appreciate Margaret’s tweet, which led me to do further research on this topic!

Given the current status of gluten testing in beer, how do you feel about drinking gluten removed beers? What do you think about the differences in regulations between the United States and United Kingdom? Tell me in the comments! (I think I’ll be sticking to wine, thanks.)

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10 thoughts on “Gluten test: can you detect gluten in beer?

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  4. Raia T.

    Well, I am not a beer fan at all, but if I were I’m pretty sure I wouldn’t be ok with drinking gluten-removed beer. :/ It’s just not worth the risk.

    Thanks for sharing this with us at Savoring Saturdays, Tracy. Hope to see you back again this weekend!

    1. GFTracy Post author

      The best way to avoid getting glutened is just not drinking it, haha! I was just beginning to like beer when I had to give up the gluten, so I haven’t missed it as much.

  5. Pingback: Gluten free beer – is it really safe for coeliacs? | talkhealth Blog

    1. GFTracy Post author

      “Buyer beware” is the best advice when dealing with gluten-removed beers. Unfortunately, as we both found out, in the UK they allow gluten-removed beers to be labeled “gluten free.” One doesn’t generally think that the government would allow such a misleading practice, but sadly this is the norm here! This is one place where the USA is doing it right.

  6. Ethan L

    I appreciate the in depth research you’ve done in the couple of articles of yours that I’ve read. As a gluten intolerant American currently studying in the UK, I’ve struggled to find “fully” gluten free beers (brewed with gluten free grains) so I tend to stick to ciders. I tried the Daura Damm GF beer, which I bought in the gluten free section in Tesco, and was sick after just drinking one bottle. 0/10 would not recommend. Didn’t get 100% back to normal for 2-3 weeks. I generally don’t even worry about cross contamination and am ok – I eat chips (fries) all the time which is always a cross contamination risk. I turned 21 since I’ve been in the UK, so I’m looking forward to going back home this summer and seeing how the GF beer differs in the US! Anyway, I appreciate the research here as I still cannot believe that every time I walk by the gluten free section in Tesco, that beer that caused me a major reaction is still there available for purchase… It’ll be interesting to see how the research in this area progresses.

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