Brewer’s Perspective: Going Gluten-Free with Ghostfish

The production team at one of the world’s most accomplished gluten-free breweries lays out the alternative routes they take to making great-tasting beer—without barley, wheat, or oats.

Joe Stange , Jamie Bogner Jul 5, 2022 - 11 min read

Brewer’s Perspective: Going Gluten-Free with Ghostfish Primary Image

There are breweries that make gluten-free beers for a market segment. Then there are those that throw their whole craft behind gluten-free as a mission, constantly tinkering with different grains and processes, always striving to produce gluten-free beers that can hang with any other beers, full stop.

Seattle-based Ghostfish Brewing is one of the latter, embracing a surprising variety of grains to make tasty beers that anyone can enjoy. Their peers apparently agree—judges at the Great American Beer Festival have awarded five medals in the past six years to Ghostfish beers, including two golds for their Watchstander Stout.

We want to live in a world where gluten- free beers can be as delicious as any others. Along with other dedicated breweries such as Holidaily in Golden, Colorado, and Glutenberg in Montreal, Ghostfish is making the case that we already live there. So, we reached out to the production team for insights on how they’re doing it.

Reid Ackerman, Head Brewer

It can be very intimidating to approach and engage with these alternative ingredients, such as millet, rice, and buckwheat—even for the experienced brewer. That technical aspect is typically the part that new brewers struggle with most: getting good efficiency out of their mash. That’s a function of several factors, including proper milling, the use of enzymes, and equipment limitations.



Each of the aforementioned grains has its own inherent difficulty with milling. Millet, for instance, is very small and requires a very tight mill gap to get a decent crush. Rice, on the other hand, is comparable to barley in size but far less friable, so it can either lead to your mill getting jammed or wearing your rollers down earlier than expected. Buckwheat, being a pseudo-grain, doesn’t play by the rules. It mills with ease but leaves behind a lot of fine particulate and hull.

Optionally, you could always bypass these challenges by buying pre-milled grain from suppliers for a small surcharge. At Ghostfish we have a nice mill on which we’ve dialed in a single setting. It can get a good crush across our spectrum of grains without having to adjust. If you’re brewing at home, however, you may need to change settings frequently and make multiple passes to ensure a good crush.


When mashing with traditional ingredients such as barley, you determine your mash temperature by how dry or sweet you want the beer to finish. You accomplish this by catering to different enzymes endemic to the grains being used, providing the optimal conditions for specific enzymes at different points in the mash.

However, with gluten-free brewing—that is, with non-traditional grains such as millet, rice, and buckwheat—there aren’t enough of these naturally occurring enzymes to get an efficient mash. So, we have to employ the use of exogenous enzymes—meaning we have to add the enzymes ourselves. In spirit, it’s very much the same approach, except with more focus on the optimal pH and temperature range, to make sure we activate that enzyme cocktail to the degree needed to ensure proper extract, attenuation, etcetera.


Mashing & Lautering

Likewise, lautering can be a challenge with alternative grains. With more flour-like fine particulate but fewer decent hulls to help filtration, mash performance can suffer, leading to lower efficiency. Rice hulls can help. We typically use about 25 pounds (11 kilos) of rice hulls for a mash of 750 to 900 pounds (340 to 400 kilos) of grain. (At homebrew scale, that’s about five ounces per 10 pounds.)

Equipment can help, too. Without specialized false-bottom screens, fly sparging may be out of the question, as too much particulate ends up getting through. The mash bed of these grains turns Wolfgang Kunze’s book, Technology, Brewing & Malting, on its head—the conventional knowledge of how to work a mash doesn’t seem to apply. It wants to drop out and form a solid mass instead of floating like a barley-malt mash, so you need to do more mixing and disturbing the grain bed just to keep things suspended and to avoid a stuck mash.

This difficulty is compounded by how long these mashes tend to take. Some of our high-gravity mashes can take up to three hours to get full conversion on our system. In the meantime, one benefit of additional mixing is that it ensures distribution of that enzyme cocktail throughout the mash. It also helps to ensure consistent increases in temperature across the bed as you go through your mash steps.

Building Tasty Gluten-Free Recipes

When it comes to building recipes, and to re-creating gluten-free versions of established styles, there are some that can be pulled off easily with the drinker being none the wiser. Others, however, will always taste different than one might expect. Even when using a maltogenic amylase—that’s one of those enzymes, and it breaks starch down into maltose—the body of these beers tends to end lighter and with a somewhat thinner mouthfeel. That makes beers such as stouts, barleywines, and hazy IPAs just that much harder to pull off successfully. Adjuncts such as oats or flaked quinoa are a great way to overcome this limitation, as are extended boils.


However, if you use oats, always ensure that the ones you’re working with are gluten-free. Even so, be aware that some folks are still sensitive to oats, so their presence always needs to be clearly communicated to avoid uncomfortable reactions.

Some styles, meanwhile—such as sour, mixed-culture, and saison beers—lend themselves exceptionally well to these alternative grains. When it comes to personally witnessing people who can’t tell gluten-free versions apart from barley versions, these styles are far in the lead.

The Character of the Malts

At Ghostfish, our primary grains are millet, rice, and buckwheat. Millet from Skagit Valley Malting is our primary base grain, providing the bulk of our extract as well as a laundry list of various malt styles that are often comparable to barley-malt varieties. We use rice and buckwheat to a lesser degree, depending on the beer style, often with rice employed as a specialty malt. (There are some great choices from Eckert Malting, such as their James’ Brown Rice malt, which gives an enticing smoky flavor along with the light roast you would expect from a darker malt.)

I’ve found buckwheat to have a range of flavors in its base format. Typically, it seems to taste fairly nutty, leading many to use it to a lesser proportion—but you can mask this flavor fairly easily downstream, depending on the style. That’s where a bit more ingenuity in your process and recipe formulation comes in. I’ve also had some buckwheat malts that expressed rose, chamomile, and green tea on a hot steep.


Millet, for the most part, plays sweet and bready—although the pale malts can come off a bit nutty as well. It can get weird: Using rice malt in excess of 50 to 70 percent can result in a strange wintergreen flavor. However, with the right mash process, you can get around this. As a benefit, you get great extract for less cost—since rice can be relatively inexpensive compared to other gluten-free malts.

The unique offerings from these different malt houses—such as Skagit Valley, Grouse, and Eckert—open up a whole new palette of flavors, aromas, and colors that you can use to put twists on existing styles or even create new ones. I’d encourage anyone out there—gluten-free or not—to experiment with these alternative malts. Play around and see what you come up with.

Tae Caldwell, Brewer

Caldwell came to Ghostfish in September 2021 from Columbus Brewing in Ohio—an experienced brewer who’s new to gluten-free brewing and its quirks. Here’s his take.

Millet is a great substitute for wheat—bland, but very sweet. Buckwheat is not really a substitute for anything, but it does have a strong, nutty, roasted profile—so it’s more of a specialty grain. Rice, by itself, doesn’t provide too much character, but it’s the perfect malting companion. It can copy pale malt, toffee, caramel, and coffee notes. Quinoa provides sweet and earthy notes, and it can mimic oats.

When blended in various ways, these non-traditional grains can provide so many qualities that mimic barley malt. They can copy the flavor profiles, and they can also provide more body and great head retention. That sets us apart from typical gluten-free breweries. We stand by our grains!

Personally, I’ve found it challenging to re-create beer profiles sometimes because you can’t always get specific specialty-malt flavors from our non-traditional grains. But we do pretty well at hitting those styles on the nose, nonetheless. It just takes time to actually work through all of our different types of rice, buckwheat, and millet to build the perfect grain bill. The biggest thing for me, besides providing a familiar taste, is the mouthfeel—that’s where a lot of other breweries fall short, it seems.

As far as technical challenges, one of the biggest things I’ve had to learn coming from barley brewing is enzyme conversions—being able to conduct a step mash and raise the temperature evenly, to provide optimal conversion, and to pull the proteins from the non-traditional grains. It has to be a strict process because if the temperature isn’t controlled, you can “burn” your enzymes and not get the target gravity you want.