Wyeast 1084 Irish Ale Yeast Went Crazy!!

[BeerAddikt]

I recently picked up a diffusion stone, wand and regulator hooked up to O2 so I can aerate properly, which has resulted in my beers really taking off and fermenting out quickly.

One side effect is the temps are rising very aggressively within 12-24 hours which has been hard to maintain using my CoolBrewing bags but up until now I've managed.

On Saturday I brewed a batch of oatmeal stout and did a 1L starter using Wyeast 1084. I've never seen my airlock work so hard before...it was literally a non-stop stream of CO2 (we're talking 5+ bubbles per second). After 12 hours my wort went from 64F to 71F and I could not control the temp no matter how many frozen 2 liter bottles I used. The yeast was just tearing through the wort like I've never seen before.

Has anyone else had this experience with Wyeast 1084 or am I just witnessing the effects of my aeration setup? The yeast is rated up to 72F but I'm thinking it was closer to 75F at the center of the wort so I'm concerned about off flavors. I could not rein in the temp, it was unreal.

 

[RM-MN]

When you add pure O2 your yeast multiply quickly which gives you more yeast cells than normal so then they ferment quickly. You may need to use a tub of water with the frozen bottles of water to maintain the temperature as the Cool Brewing bags can't remove the heat produced quickly enough. The water in contact with the fermenter will be much more efficient in removing the excess heat.