If you had a chance to taste one of our gluten-free beers, you know we like to play with the concept a little. Most of the gluten free beers out there are pretty mediocre, or well made but simply uninteresting. How many gluten-free pale ales do we really need? This lack of variety partially comes from a lack of variety in the raw materials. Sorghum extract is the main ingredient in most gluten free beers. There aren’t many easy ways to spice up the recipes from there, so most breweries seem to just add hops and call it a day.
I’ve been trying to move beyond this, to see what you can really achieve with gluten free raw materials. I started out by jumping straight into a style that I thought would actually compliment the few raw materials you can easily use, the saison style. This worked really well, as the flavor characteristics created by the yeast blend naturally with the sorghum extract, and I’d throw in some cane sugar and honey as well. I went one step further by experimenting with herbs and spices that I thought would further blend well with the existing flavors. I first did a lavender, vanilla, and grains of paradise gluten free saison. That’s one of my favorite recipes I’ve ever created. Next was the Norcal Winter gluten free saison with douglas fir tips, juniper berries, bay leaves, and some bright spicy hops.
The next step for me was to move to all-grain gluten free brewing. All grain gluten free brewing would open up many new possibilities in regards to raw materials. I’d no longer be stuck with the sorghum extract and adjunct, and would be free to use almost any gluten free source of starch: amaranth, quinoa, millet, buckwheat, corn, rice, etc.
However, all grain gluten free brewing presents some challenges. First is the fact that the grains are not malted and therefore lack sufficient diastatic power to convert their starch to yeast-edible sugars. Second is the absence of hulls or husks that would provide a natural filter bed, as barley hulls do. There’s plenty of other challenges but those are main ones I needed to overcome to make a successful gluten-free wort.
I purchased a grain mill with an adjustable gap. I did some experimentation to find the correct gap for each gluten free grain I was planning on using. Quinoa, millet, buckwheat. The corn comes cracked (grits) and the oats are flaked so no need to mill them. I toasted the oats for a bit to develop some flavor as well.
To overcome the lack of diastatic power in the non-malted grains, I turned to exogenous enzymes. I have a high temperature stable alpha-amylase enzyme, and a beta-amylase enzyme that would do the trick. The milled and flaked grains were mixed with water, brought to a boil with the high-temp stable alpha amylase enzyme, and held at about 90C for while. Then they were boiled again for further gelatinization. Then another 90C rest with more enzyme. I dropped the temp down to 60C, and added the beta-amylase enzyme. A 30 min rest and an iodine starch test came out only slightly positive. I figure the rest of the conversion would occur as I lauter.
The next challenge was to overcome the lack of hulls, and therefore the lack of a natural way to separate the wort from the spent grains. I approached this by using rice hulls. A few pounds of rice hulls in the mash/lauter tun, and in went the converted cereal mash. The rice hulls worked reasonable well to clarify the wort. I’d say it was a success given that it was the first try. The wort was still fairly turbid, but certainly much less so than the cereal mash itself. Another iodine starch test shows that the wort is starch negative!
I added some sorghum extract (ok, not quite full-grain now) to bring up the gravity, and proceeded as normal. A gluten free saison yeast in the cooled wort was left to do its thing.
An OG of 1.070 became an FG of 1.003 in about 10 days. That’s a dry saison! And pretty high ABV at 8.9% as well. I wasn’t expecting it to dry out quite that much. Apparently the enzymes really broken down the starch, leaving few dextrins. A saison yeast is typically a high-attenuator as well, so those two combined made for a very dry beer. Some things to play with there, to modify sugar profile and resulting fermentation.
So, first full grain gluten free beer is a great success. The process raised many questions and fostered lots of ideas, and there is a lot more fun experimentation ahead!