Since I was going to rely so heavily on oats for this beer, I decided to set up a little experiment. I wanted to see what characteristics I could get from regular oats (bulk steel cut thick oats). I preheated my oven to 375F and spread out 3 lbs of oats over two pans. Every 10 minutes, I took out some oats and set them aside for comparison. I tasted the oats themselves, and also made a tea from the oats to see what flavor could be extracted.
I put the bottom row of oats right – left in order of time to allow easier comparison between 40 and 50 minutes. I only had 8 cups, so there is no picture of uncooked oat tea (1/4 C oats in 1 C hot water, microwaved for 2 minutes, and steeped for about 5 minutes more).
Here are my impressions of each level of roast:
10 minutes: The oats had a floury flavor and subtly thick mouthfeel. The tea had a soft smell and a mild floury flavor.
20 minutes: The oats tasted a lot like sunflower seeds, less floury – still very mild. The tea was slightly more nutty with a bready mouthfeel.
30 minutes: The oats still had a sunflower seed flavor but a bit more dry and bitter. The tea smelled sharp and maybe a little sour. It tasted more nutty than the 20 minute tea, and had a thicker body.
40 minutes: There was a slight burnt flavor to the oats, kind of like the crust of whole wheat toast. The tea tasted like it smelled, with subtle coffee flavor in the background.
50 minutes: The oats had a strong, somewhat unpleasant, bitter flavor. The tea had a fainter smell than the 40 minute tea, but the burnt character is noticeable. The tea tasted more strongly of coffee, with a nice roasted flavor.
60 minutes: The oats started with a slight bitter taste that built in the mouth. There was an espresso bean type flavor. The tea tasted milder than the 50 minute, with noticeable coffee and nut (not sunflower, though) flavors.
70 minutes: The oats still had a coffee flavor, but it was starting to mellow and be replaced by a faint burnt flavor. The flavor had a pronounced roasted, slightly burnt, nut flavor. Both the oats and tea tasted very nice.
80 minutes: The burnt flavor in the oats is more prevalent, and beginning to overpower the coffee and nut flavors. The tea had a more roasted smell and somewhat sharper, but not overpowering, burnt flavor.
That’s where I ran out of oats. I’d love to go back and see what happens if I cooked them for 2 hours, or if I just let them get really charred. I was surprised to see that the even the 80 minute tea wasn’t particularly dark, more of a nice amber color. I am curious to see if there is a point where the oats would impart a nice dark color to the beer without being too burnt tasting.
I was also surprised at how significantly the flavor of the oats could change just by roasting them for different periods of time. I found that the best flavors actually came from mixing some of the roasts together. The 20, 40 and 70 minute oats combined very well to compliment each others’ flavors. I’m sure as I experiment, I will find other combinations that are just as appealing.