So, I’m brewing a tribute to Tired Hands’ flagship pale ale - Hophands. A lovely beer worth seeking out. I’m roughly following Ed Coffey’s recipe, except I’m using Briess pale ale malt as my base along with ~16% old fashioned oats, and I’m gonna use the new White Labs dry yeast version of their London Fog ale yeast, which I’m excited to try.
Everything went smoothly, except I missed my preboil OG by the number of gravity points equivalent to the oat fraction’s contribution. I am perplexed. Old fashioned oats should be amenable to conversion by my base malt, right? My understanding is that oat gelatinization occurs at close to mash temps, so a separate cereal mash shouldn’t be necessary, right?
I was able to make up the gravity difference with DME, so no worries there. However I wonder if I should have done something differently? I did include rice hulls in the mash. Should I have also included some 6-row to provide additional enzymes?
For what it’s worth, the oats were ‘expired’ - their best by date was August of last year. However, the Quaker old fashioned oats were still sealed in their bag (I buy the large Costco product with two 5lb bags of oats), and the oats smelled & tasted good & fresh, there was no moisture or oat clumps in the bag, no tell-tale signs of spoilage, etc. Grain stored dry can last a while so I wasn’t concerned.
Anyway, just wondering if any of y’all have any idea as to why my oats didn’t convert? Thanks, appreciate it!
Old fashioned oats are steamed then rolled (aka flaked). Quick oats are flaked oats cut into pieces to create more surface area to cook faster. You shouldn’t need a cereal mash for either.
There could be a number of reasons behind why you did not hit your planned OG. The expired oats could be the reason, or a bit of six row could have helped, or dough balls, or any other number of contributing factors attributed to process, technique, or the fact that you’re dealing with agricultural products that have inherent variability. We tend to expect the raw material to be consistent yr to yr, batch to batch but it simply isn’t.
For example, I recently had the opposite problem. I overshot OG by a metric mile. I had to add RO water to dilute the gravity. While Amber and lighter have been spot on, Dark beers have tended to end up high in my brewery lately. Like you, the important thing is I took measurements, recognized the problem, and applied a simple fix.
To account for variability, I allow close enough to be good enough. A point or three here or there is acceptable to me. Occasionally, I end up outside close enough tolerance so adjustments have to be made sometimes planned, sometimes on the fly. I have DME as well as several types of sugar on standby. Fortunately, I don’t have to use them often.
Most common problem with oats usually comes down to forming dough balls in the mash resulting in improper hydration, gelatinization and conversion. A cereal mash isn’t necessary but it will help with avoiding dough balls by gelatinizing the oats before they hit the mash which helps avoid those dough balls. An easier solution is just stirring any mash with oats more than you normally would.
Water content in grain will also affect the weight which can also reduce your gravity by leading you to use less grain than you should. With rolled oats the interior of the grain is exposed and able to absorb moisture better than an unprocessed grain. You mention the oats were a little long in the tooth. Moisture absorption could certainly be a little bit of your problem. As BrewBama points out, there can be variability in starch content in the oats you used. It doesn’t take too much of a reduction in starch content by weight to see a change in gravity.
But I am confident spending a few more minutes stirring the mash and pondering the meaning of life would get you very close to your desired outcome.
I do the same thing when I miss my gravity. If I am within 4% of predicted, that is good enough. If I am 2% off or less, it’s high fives all around.
However, I have never had an issue where a dark bigger beer exceeds the predicted OG. I usually have to revise the recipe to add a bit more grain or add DME to bring it up to snuff.
I also agree that problem may be the age/type of the oats. I only use flaked oats when I make a beer that uses this ingredient. That way i can be sure they are pre-gelatinized.
Of course, I could be mistaken but I thought steel cut oats required a cereal mash. Because old fashioned were steamed/rolled (flaked) and quick oats were simply cut up old fashioned they don’t require a cereal mash. [emoji2369]
I dont think I had any doughballs, although I did not stir with my mash paddle any more than for a standard mash, so next time I will definitely stir a bit more. I did add rice hulls as I said, which if they are properly interspersed into the mash along with the oats in theory should mitigate against dough balls as well as aid in lautering, but yeah I wasn’t as careful as I should have been.
Wondering why old-ish oats would matter all that much? I wouldn’t think they’d lose fermentables over time, unless some of the sugar & starch is getting converted to lactic acid and/or ethanol by resident microbes, which I suppose is possible.
In any case, it was a RDWHAH situation, DME to the rescue! Hopefully I still get the silky smooth body contribution from the oats, but if I don’t I’ll make sure to never use expired oats again! Again, they tasted perfectly fine - no rancidity, and they were factory sealed the whole time so shrug.
Another possibility is that the gravity points per gallon in your brewing software or spreadsheet isn’t quite right and is over-estimating their gravity contribution. I would think that the expiration date has more to do with the likelihood of going rancid or getting infested with insects that affect the amount of starches in the oats.
Ugh… 24 hours later and no signs of fermentation. Starting to think I should’ve gone with my usual route of liquid yeast + starter and O2. All I did was sprinkle dry yeast directly into the wort as the package directed. Should I see activity by now, or given how I just sprinkled it into the wort without rehydrating should I expect such a lag time? Is this a RDWHAH moment?
What yeast strain? I have had a 36 hr lag before with certain strains.
Lately, I use Go Ferm to hydrate dry yeast in a mason jar of water shaking vigorously from time to time during the mash, boil, and chill processes, then I add Fermax and shake to mix just before pitching. This seems to work very well. Kind of my version of SnS.
I wouldn’t be worried at 24 hours. It’ll take off… If you’re looking for airlock activity, might go ahead and make sure everything is sealed up/tightened, just as a precaution.
I never use airlock activity as an indication of anything. In fact, I don’t even use an airlock at all for the first half of fermentation. Just a bit of foil over the opening works just fine, most yeast appreciate a low head pressure 'open fermentation ’
Well as usual I panicked over nothing
Finally seeing a baby krausen a little over 36 hours in. I suppose pitching dry yeast directly into wort, which is something I admittedly haven’t done in a while, just results in longer lag times than pitching a rip roaring starter of liquid. RDWHAH it is!
Used old fashioned oats for the first time this weekend. I cooked the oats for a few minutes, dropped the temp and added a pound and a half of base. I let it sit at 128 for 15min. Brought it up to mash temp at 155, and added it to my mash. I underlet, so the during the 15 minutes the mash was hydrating. Stirred it all well and off to the races.
When making my oatmeal stout I use old fashion oats that comprise 25% of the grain bill. Never had an issue with conversion or a stuck mash. I do mix the grains very thoroughly prior to mashing so the grist is vey uniform. Not sure if that makes a difference