GF Brewing for Barley Brewers
This page is intended to summarize key considerations for people who have conventional barley brewing experience and are either switching to gluten free brewing (due to a celiac diagnosis for example), or looking to expand their brewing scope to include both gluten-free and gluten-containing beers (BROW: Barley, Rye, Oats*, and Wheat).
Equipment and cross-contact
At both the home and professional level, if you are contemplating re-using equipment previously used with gluten containing grains, you need to assess possible risks and take steps to remedy. Due to the low threshold for cross-contact with gluten for people with medical reasons to avoid it, the best option is new and dedicated equipment. Grain mills and equipment with more intricate parts where very small gluten particles may hide (mash tun manifolds, ball locks, etc) are the biggest concerns.
Making a shift to gluten free brewing should be relatively straightforward for brewers who use extract (malt syrup or dry malt extract) ingredients only. While there are fewer gluten free extracts to choose from (unmalted sorghum syrup or rice syrup), there is no mashing of grains to worry about, and enzymes are not required to convert starches to sugar. See below for considerations on gluten free yeast.
Partial grain aka partial extract
An intermediate brewing approach is to augment liquid and/or dry extract with specialty grains (steeping rather than mashing). Like extract-brewing, this transition is fairly straightforward and can be done without enzymes or mashing where the steeping grain is simply providing color, roast flavor or some sugar (i.e. crystal malts). Because it is still necessary to crush grains for steeping, this again requires reviewing the safety of milling equipment that might have been used with gluten containing grains. See below for sourcing fermentables and yeast.
All grain brewing
For those with all grain brewing experience, transitioning from conventional to gluten free brewing will be a more significant shift with a sizeable payoff: there are quite a few new variables and challenges to contend with, but ultimately some great opportunities to improve your understanding of brewing science, particularly in the areas of enzymes and the mashing process.
Malt and fermentables
One of the first things to familiarize yourself with is the types of fermentables available to gluten free brewing. Barley, wheat and rye are definitely out, but in exchange you get a new and longer list of fermentables to work with. Rice and millet have become the main base malt workhorses with buckwheat, corn and other grains/pseudo-cereals playing supporting roles. In some cases you will find fairly good equivalents to different barley malts, but frequently it is hard to specify 1-to-1 substitutes for flavor or brewing character.
- See draft list of conventional to gluten free malt options
The ability to source commercial gluten free malts will depend very much on your geographic location. Brewers in the US and Canada likely have the best and most economical options to choose from. Australia, New Zealand and the UK have slightly more limited availability. In Europe and Asia there are currently no domestic gluten free malt producers that we know of, and supply may be dependent on imports or malt-it-yourself methods. Note that there are now maltsters who fall into either a dedicated gluten free or mixed gluten and GF grain category. Many GF brewers and consumers will be inherently more comfortable with dedicated operations where the risk of cross-contamination with gluten containing grains is considerably lower. Provided there is adequate separation, risk management procedures, testing, and transparency, a wider spectrum of maltsters may lead to lower costs for gluten free malt, which is significantly more expensive compared to barley.
Enzymes and mashing
All grain barley brewers will be accustomed to (and possibly take for granted) two basic facts about barley malt:
- It generally has enough diastatic power to convert starches to sugar without the need for exogenous enzymes
- Gelatinization temperatures of barley (and wheat malt) are aligned with the temperature ranges of alpha and beta amylase enzymes
For this reason, many all grain brewers can think in fairly simplistic terms when it comes to mashing: A lower mash temperature will allow beta amylase enzymes to more fully break down starch chains for a more fermentable (possibly drier or lighter bodied) beer. And a higher mash temperature will tend to create a wort with a higher ratio of longer chain sugars and dextrins.
Gluten free brewing brings a few challenges in this area. For one, the diastatic power of gluten free grains is generally much lower to begin with in gluten free ingredients. Beta amylase (which focuses on maltose production) is associated with the gluten proteins in barley, wheat and rye, and are wholly absent in gluten free grains. Gelatinization temperatures for gluten free grains is significantly higher than barley. This means that to properly access the starches in these grains, it's often necessary to heat them to temperatures that negatively impact (denature) the alpha amylase and limit dextrinase enzymes that are naturally occuring in the GF grains.
While there is some opportunity to preserve and utilize endogenous enzymes only (see Lavery mash method), many commercial and amateur GF brewers have embraced the use of exogenous enzymes to better predict and control wort production. No longer limited to the blunt force of glucoamylase enzymes, there are now multiple commercial brewing enzymes aimed at different elements of mashing steps, including break down of beta glucan, debranching of amylopectin, and maltose production.
As gluten free brewing practices evolve, there is still a significant amount of experimentation around mash routines. Those methods are often tied to different combinations of enzymes (each with varying active temperature ranges). A single high temperature infusion mash is possible, but may not provide the best conversion efficiency or wort fermentability. For that reason, many GF brewers have developed a preference for one of several different step routines (usually a rising or falling temperature step depending on where the gelatinization takes place).
Regardless of how you produce your gluten free wort, experienced barley brewers may be surprised to confront the yeast factor in GF brewing. The Zero Tolerance stance (aligned with labeling legislation in the US, Canada, Australia and New Zealand) is that gluten free beer cannot contain ingredients that are not naturally gluten free. Gluten free yeast for gluten free beers must be propagated on gluten free media. Liquid yeast from most commercial yeast labs (or cropped from gluten containing beers in your brewhouse) do not meet that test. There is a small handful of commercial yeast laboratories now offering gluten free liquid yeast options and a growing list of GF-certified dry yeast strains.
- See Yeast