All of these forms can be used in brewing, but homebrewers have to understand that in order to get sugar from them, they need to be mashed with base malts. The higher yeast growth and reduced lag time resulting from the increase in fatty acids seems to make a great case for using high percentage of unmalted oats when making yeast starters! Mouthfeel is the result of various factors, including beta-glucans, ethanol, glycerol, and glycoproteins. Harvested yeast that is continually reused for brewing results in a reduction of unsaturated lipids in the yeast cells and a deterioration of growth during fermentation.18 It was found then that yeast supplemented with lipids, especially unsaturated fatty acids (which oats are high in) improved fermentation.19 Although this was direct supplements of fatty acids, it does seem logical to conclude that high lipid worts from adjuncts like oats, could help improve fermentation of older generation yeast. #11 Ten_SeventySix_Brewhouse, Jun 19, 2017. Many online sources recommend a cereal mash when using raw oat groats because unlike flaked oats which have already been gelatinized in the flaking process, raw groats are exactly that, raw. The Schnitzenbaumer study also looked at head retention in oats and found when using oats at about 10% of the grist, there was no negative effect on head retention. You provide a gelatinization range (135-162f) for oats that is well above the range (127-138f) provided by the BeerSmith cereal mash link in the above article. I have been brewing for quite some time with oats. A cereal mash allows you to cook the adjunct used in brewing to gelatinize them which will allow mash enzymes to access the starches. A. These are the main techniques for using oats in beer. Oats, Wheat & Rye: What Adjunct Grains Add to Your Beer October 28, 2014. aMost craft beer drinkers would agree that we love complexity in our beers. Brew your best beer EVER. At the end of chapter 7 is a table with sensory panel results. 802-362-3981. The oats could very well have played a part in increasing body/mouthfeel but was overshadowed by a hidden factor. Oats also contain higher level of lipids than any other cereal grains and are high in the three major fatty acids (palmitic, oleic, linoleic). Beers high in oats could potential reduce common off flavors as well as improve beer stability. Ester production stemming from increased amount of oats led me down a rabbit hole of studies with conflicting results. Direct Supplementation of Yeast with Lipids as a Means to Reduce Sulfur Dioxide Formation. Bumping protein-rich grains like malted wheat in combination with oats has seemed to help a bit with getting both body and silkiness. Oats also contain higher level of lipids than any other cereal grains and are high in the three major fatty acids (palmitic, oleic, linoleic). So it could be that the mash schedule and lager yeast used in the experiment played a much bigger role in the body than the oats. This same characteristic can make its way into a beer so it has been common in many recipes for beers like brown ales, winter warmers, and porters. When I have brewed with 40% raw steel cut oats, I milled the groats twice through my mill and was able to achieve 64% mash efficiency after a long 2 hours mash (using oat flour may also boost efficiency). Free Amino Nitrogen (FAN), the level of amino acid nutrients in wort used by the yeast for healthy fermentation is typically supplied by malted barley. It’s actually amazing how much oats will raise the beta-glucan content of a mash. Don’t feel limited to simply brewing dark beers with oats either. This may make the case that oats could be used in session beers when you want a lower ABV, but still have some body remain to have the impression of a bigger beer. So let us take a look at some of the emerging grains that have been playing a bigger role in … Stouts made with about 10% oats have a sweeter, smoother flavour. Sulfur dioxide can be another off flavor in beer. The beta-glucans along with other components are well known to help build body in beer, but when it comes to mashing they can cause headaches in the form of slow run-off from the mash tun. Many online sources recommend a cereal mash when using raw oat groats because unlike flaked oats which have already been gelatinized in the flaking process, raw groats are exactly that, raw. Malt analysis of oats shows a very low level of nitrogen modification, which leads to low malt soluble nitrogen. As the oats in the mash increased in the Schnitzenbaumer study, the lag phase of the yeast decreased with the oat containing beers having a 94% higher yeast growth after the first and second days of fermentation than a beer brewed with 100% malted barley! I removed all of the beers that were made without clean ale yeast (any saisons, sours, etc.) With my brews, I just go ahead and get flaked oats from the HBS since I know I won't need any pre-mash steps. Oats high in fat content have been shown to be highly susceptible to rancid characteristics and bitter flavors when processed. There are several tricks to avoid this headache, but the addition of some rice hulls to your mash is the easiest solution. This is the case with oats, with no oats (100% malted barley) the FAN was measured at 177mg/L with 40% of the barley substituted for raw oats, the FAN dropped to 131 mg/L.7 A more recent study on on the fundamentals of yeast nutrition recommends lower levels of FAN than was typically quoted in brewing literature saying the minimum FAN content in wort should be 100mg/L for healthy yeast.8 So it appears that using oats even up to 40% (or even more) of the grist, there really is no concern with FAN for yeast health. Enroll in the BYO Digital Membership plus subscribe to Brew Your Own magazine. They did not find a link in linoleic acid to the reduction of esters, saying that “if unsaturated fatty acids inhibit the enzyme (as MacDonald said above) both the inhibition and the induction of the enzyme would have to occur at the same rate to explain the data.17 In addition, the Schnitzenbaumer study found a 14% increase in esters with 40% unmalted oats. So based on this information, I charted all of the beers I have brewed where the total oat content of the grist exceeded 10%. Specifically, beers with 30%-40% oats had the lowest levels of head retention. Intermediate ABV beers have better head retention than extremely low and high ones. Another positive in brewing with oats is it’s ability to improve beer stability. I’m not sure what source was used for BeerSmith, but I cited mine for the gelatinization range. Here come the possible benefits of oats again, it was found that yeast supplementation with lipids can be used as an effective means to reduce the amount of sulfur dioxide during fermentation while stimulating overall yeast growth.