Insane fermentation - losing serious beer

[Potamus]

I started up a lambic Saturday afternoon using 1 pound flaked wheat, 3 pounds wheat DME, 3 pounds light DME, 1 ounce saaz and WLP 550. I got the ingredients at the last minute and didn't have time to make a starter.

Turns out, that isn't going to be a problem. Krausen was forming by Sunday morning, and I needed a blowoff in the 6.5 gallon carboy by Sunday afternoon. As of this evening, I appear to have lost about a half gallon of wort to the blow-off. The wort level started at the top of the blue line on the carboy, if you can make it out in the picture.

Normally, I wouldn't worry about it and just take the hit on volume, but in this case I'm planning to pitch some bugs and let them get to work for a year or so. With losing all this wort, I'm worried that when I rack to a 5 gallon secondary, I'm going to have too much headspace.

So I'm wondering first how long this will continue and how much wort I can expect to lose. Also wondering if I should consider topping off with water or more wort (from the wheat beer to the right, perhaps) to minimize headspace in secondary. Or will the pellicle keep it safe for the year?

 

[Espresso]

This could be more easily answered if we know what temperature the wort was when you pitched the yeast, and what temp is it now (or ambient air temp)? This is because a higher wort temp can lead to this. It could go on for a day or two.

 

[Facinerous]

I've used filler material in the secondary for make up for headspace before. In my case I used glass beads you can buy pretty much anywhere. Just added them to a pot and boiled em for 20 min or so. Called it good. You can sanitize em also if you want to if you didn't want to add any top off water.

As far as how much liquid you will lose to blowoff that is extremely hard to tell. Wish I had a better answer for you than that.

 

[Potamus]

I pitched at 70 degrees and ambient is steady at 64 degrees. Thanks for the quick replies!

 

[Calder]

550 is a beast. I did a tripel last week, used fermcap and lost a couple of pints when I wouldn't expect to lose any with other yeasts. I did ferment at 74 on purpose.

Since it is an extract batch, you can top up with some extract boiled to the same gravity as the original.