Quick fermentation?

[M Baldwin]

Hi, all. I'm Mark, new to the forum and have a few questions. I used to dabble with extract brewing but felt the best way to get what I wanted was to switch to all grain. My current set up is an Anvil 6.5 gallon Foundry, and I'm using the Anvil 4 gallon fermentor. I'm using a Tilt hydrometer to monitor fermentation.

The two beers that I want to focus on are Double IPA and Imperial Stout. They are my favorite beers after all. I know they are above my pay grade a bit, but nobody ever accused me of being smart.

Anywho, I think I'm getting the swing of things on brew day. I'm hitting my numbers and I'm fairly confident that I have a good process after four or five brews. My main challenge now is controlling fermentation. Each of the beers I've made so far have gone from 1.07* down to below 1.015 within 36 hours. At this point they still look like they are in the vigorous blow off phase. Like, really, they're cranking! I'm trying to keep the temp around 67 on my current brew, an Imperial Stout. This beer is underpitched, as my wyeast 1028 didn't even begin to ferment...so... I had two packets of Ale yeast from one gallon NB kits and repitched with them to see if I could save it. In no time at all, the little beasts shot through the wort.

My real question is why is it going so fast, and should I try to slow it down? Before I had the Tilt, I would have just let it sit until the bubbles got slow before even checking the gravity. That way of doing things seems to be getting thrown by the way side if I'm hitting my final gravity number so quickly. I'm thinking I'm going to move this brew into a secondary tonight and leave it there for a few days before I move it to long term storage in bottles.

Sorry about being long winded. Thanks for any wisdom anyone may share!

 

[Megary]

I don't use a Tilt so don't trust this unless someone can confirm it.

But I have read that a Tilt has a tendency to acquire some gunk during fermentation that makes it give lower gravity readings than actual. So the Tilt might be very useful to see when gravity stops falling and levels off, but the actual FG (as measured by a hydrometer) might be higher than what the Tilt shows.

 

[Mark Farrall]

What's your mashing process and how are the numbers for that part of the process? Just checking the fermentability of the wort. If it's highly fermentable and there's a decently amount of healthy yeast it can rip through it.

And what's the attenuation you're getting on your batches? Even without highly fermentable wort, but with a decent amount of healthy yeast you'll still see it rip through the available sugars pretty quickly. In this scenario you'll be further away from the predicted numbers for your final gravity, but I'd still expect it to be a pretty furious fermentation for a while.

I wouldn't try to slow it down. It's far more likely to be a sign that you've pitched a decent amount of healthy yeast than anything else.

For the tilt (been using them for a year or so), it's completely reliable for the pace of the fermentation and whether the fermentation has stopped. It just sometimes gives a slightly higher or lower reading than reality. This is when bubbles or krausen attaches itself to the unit and distorts the angle of the tilt. You can give the fermenter a gentle swirl or two every now and again to remove the bubbles, but there's no way to remove the krausen that's worth the risk it introduces. Once the fermentation is complete do a refractometer or hydrometer reading to confirm the actual final gravity number.

And the first recipe I created and my first all grain BIAB batch was a Russian Imperial Stout. Nothing wrong with having more ambition than ability, as long as you keep improving.

 

[M Baldwin]

Thanks for the replies.
Mark- the mash process is pretty straight forward with the Foundry. My mash temp on this batch was 152 F. I checked with iodine to look for starches after an hour. My gravity at that point was 1.076. That number was higher than expected, but I figure I just got a slightly higher efficiency than the 70% that I had calculated for. Gravity at the end of the boil was 1.081, and I had the three gallon volume I wanted.

My Tilt told me my gravity was 1.079 when I put it in the wort. That is close enough for me.

I suppose that I am surprised by actually seeing the numbers in real time during fermentation. I used to just let it sit in primary until the bubbles had just about stopped. Now I get the sense that that way of doing it was letting the beer go too long. Going from 1 gallon kit beers to 3 gallon recipes that I am making from scratch has been a learning experience to say the least!

 

[Mark Farrall]

I'm not hearing any alarm bells. Most of my fermentations for the bigger beers look like they've fallen off a cliff for a day or two once things have started and then slowly finish out.