Headspace for 1st Hefeweizen

[BrewMehr]

I'll be brewing my first Hefeweizen on Thursday. I made a 2L starter last night with Wyeast 3068 and twice made a big ol' mess on my counter. I went to the Wyeast site and I see the yeast requires 33% available headspace. For the 5.5 gallons I typically put in each fermenter, that would mean I need a 7.3 gallon carboy.

I'll be using 6.5 gallon carboys with blow off tubes and I'm expecting to lose quite a bit of yeast to blow off. Is there a downside to this? Wyeast also says to avoid over pitching due to risk of losing all esters. I was planning to step my 2L starter up to 4L tonight, crash, decant and then split between the two carboys. But since this is a low attenuating yeast, I'm second guessing the decanting. Do I over pitch knowing I'm going to lose a lot to blow off? Or should I just stick with the 2L (1600mL net) starter split between the two carboys?

Brewers Friend says my 2L starter will produce 379B cells with a target of 424B -- which seems like a nice pitch rate if the blowoff doesn't have an effect. Do I need to account for blowoff? I know I already lost quite a bit of beautiful yeast to blowoff just in the starter.

 

[MrPowers]

I make starters for most beers, but when brewing a hefe I usually just pitch a single smack pack or make a vitality starter (for 5.5 gallons). It will blowoff in a 6.5 gallon carboy, don't worry about yeast loss, it will attenuate just fine.

If I were you, I would just split the 2L starter between the two, rig up the blowoff tube, and let it ride.

 

[BrewMehr]

Thanks MrPowers. I brewed and pitched today. I put the yeast back on the stir plate to mix things up and once again it blew the top. There was only 1600mL in a 2L flask. I'm excited to watch the real ferment now!