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Oatmeal stout brewday

Pitched the WY 1098 at 3:30 PM. Wort was 64.9°F at time of pitching. 10:00 PM active fermentation at 66.6°. This was the first time I used the oven to hold the temperature of the mash. Target temperature was 154°. Mash was at 151° for 8 minutes. Temperature came up to 153° after applying some heat and stirring the grains. In the last 10 minutes of the 60 minute mash the temperature rose to 154°.

Just to double check I used the Thermapen in various spots for temperature variation. Found the bottom inch of the grains was at 157°. I’m guessing when the 6 inch Dot probe recorded 154° the temperature of the grains at the bottom was on the rise to 157°.

Hopefully the more fermentable sugars created at the beginning of the mash will balance out with what was left to convert near the end of the mash time. I doubt if there is much conversion after 30 minutes so I might be okay.

That reminds me i get to use my thermapen today :slight_smile: Did you warm the oven up at all? Or just use it as an insulated chamber?

I applied about 10 seconds of heating element time four times in the first 12 minutes to raise the mash temp from 151°. Applied some more heat at about 30 minutes. I had found our oven cools fast in testing the oven last week.

WY 1098 has surprised me this time. A very active fermentation. Nothing in my notes about an unusually active fermentation from previous uses of this yeast.

I had pitched the yeast at 64.9°F. Six and a half hours later active fermentation at 66.6°. The next day, twelve hours later at 68.9°, a steady stream of CO2 through the air lock with a one-half inch krausen. Twelve hours later the wort temperature jumped to 73.2°. Seventy-three degrees was as high as I wanted. Filled my swamp cooler and covered the fermentor with a wet towel. Just before midnight, three hours later, the wort temperature was down to 71.4°.

This morning the fermentor was at 69.3°. The krausen which had never exceeded one inch in height had dropped. Steady CO2 release continuing. If you count bubbles through the air lock it went from 14 per 15 seconds to 6 per 15 seconds in the twelve hours. I emptied the swamp cooler and removed the towel to let the fermentation finish at an ambient temperature of 68°.

Never had a fermentation with WY 1098 this fast before. Perhaps it was the yeast, a better yeast starter, or better wort aeration. In about 5 days I’ll take a SG sample and have a taste.

Sounds like the same thing kviek yeast. Super fast. But my question. Ok oatmeal. Type of grain. Do you prepare it the same. Add it to the milled grains.

Would you use the oven again? Sounds like alot of extra work.

You don’t need to mill rolled oats - they can be added straight to the mash tun. But it doesn’t do any harm to run them through the mill, as long as they don’t plug up the thing. Sometimes it’s just easier to throw all your grains together.

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I’ve been considering the two basic options for for partial mashes .

Small and well insulated cooler to hold the mash.

Getting a second Dot with the air probe to better monitor the oven air temperature.(Could use a second one for the smoker also.) Insulate the bottom of the kettle from direct heat with a pizza pan and crumpled foil if additional heat is needed.

  The oats was included with the premixed and crushed grains.

You know @flars the cooler works great as you know. I calculate my temp with an online calculator and mash in and shut the lid. No monitoring needed. Come back in an hour and the temp is exactly the same. No need to stir during the mash either. Your doing partial mash so you don’t even need a valve if you have your grains in a bag jus pull the bag and dump the wort into your pot

Started looking around. Considering this stainless steel insulated hot beverage dispenser.


Would handle 8 pounds of grain. More than enough for partial mash brews. Could actually dispense coffee at a family reunion. Price now is $46.00.

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