floaties and a major blow-off

[dbenet]

I just brewed my second AG batch on Sunday, a strong golden using 12# Pilsner 1# wheat 0.5# munich 2# sugar and WL575 (belgian ale blend). Recipe called for a double infusion; 30min at 135 then 30 min at 150f. I over compensated for absorption in the grain and added about 3qts too much water to the mash. I double batch sparged with 4 gal, vorlaufed each step and ended up with a bit more volume than intended at lower gravity; only 1.064 instead of the 1.075 I was shooting for and the wort was far from clear with lots of chunks of coagulated something floating around. I compensated with a longer boil ~ 90 min and ended up with a full 6.75 gal into the fermenter. Pitched my 1L started at 64F and had vigorous activity within 15 hours. At 30 hours temp had risen to 68F, the krausen was twice the volume I've ever had under similar conditions; clogged then blew-off the airlock in the middle of the night (feaked out my girlfriend) and I rushed to clean up the foaming monster and fasten a make-shift blow-off tube. A couple questions 1) Should I have vorlaufed more to clear the wort? I didn't measure but I must have pulled 2-3 qts each time. 2) Could the double-infusion have caused more stuff to be suspended and/or lower efficiency or possibly an inaccurate OG reading due to suspended material? 3) Could the same variables have caused such massive krausen? I've never had need of a blow-off tube before and pretty much use a 1L starter for everything. I think the beer will turn out fine, but I haven't had this reaction before and I'm still trying to get the AG process dialed in. Any pointers would be much appreciated.

 

[phatuna]

not sure about the floaties, but the blow off was likely due to the reduced headspace in your primary seeing as though you fermented 6.75 gallons. How big is your primary?

Also, belgian yeast is often very active. Most require a blow off even with 1-2 gallons of headspace.

Your OG was affected by your volume. the recipe was probably supposed to yield 5 or 5.5 into primary. you went in w/ 6.75. For obvious reasons, this will affect your lower OG.

Not to worry, it will make a fine brew.

 

[dbenet]

The primary is pretty large; I haven't measured but looks to be about a 7.5-8 gal glass carboy. I've had 6.5 gal batches in there before without issue, some belgian ales as well, but those were all partial extract brews. I haven't calculated brewhouse efficiency yet, but I imagine you're right about the lower gravity. Yet somehow, the recipe was targeted at 1.084 for the same grain bill. I lowered my target to 1.075ish knowing my efficiency probably wasn't 75%.

 

[phatuna]

You might use a mash calculator like this one on your next brew: http://www.brew365.com/mash_sparge_water_calculator.php

It will help so that you don't have to think about grain absorption etc. it is all calculated for you. just plug in the weight of your grains and how many gallons you are shooting for into primary. the rest is done.