Use carboys for starter?

I was considering using a plastic milk jug (sterilized) for my starter. Brewing 10 gallons of IPA this weekend.

Then I got to thinking, why not sterilize the two carboys and let the starter propagate in them?

Seems so obvious I figured I should ask before doing it. Any issues with this technique?

Thanks guys.

Sounds ok to me, unless you plan on decanting before brewday. It might be tough to stick the carboys in the fridge and pour off the spent wort! If you're not planning on decanting anyway, go for it!

Okay, so I suppose my next question needs to be whether I can make a big enough starter for 10 gallons with only one smack pack of yeast.

Mrmalty says I need 7 liters of "simple starter." Not sure what that is. I was planning on shaking occasionally. It also suggest two yeast packs, which I don't have right now.

Can I use one yeast pack, make a 7liter starter with it and split that volume in my two carboys? Hence, two starters? Or can I make 2liter starter tonight, cool it down tomorrow, decant and then step it up into the two carboys tomorrow?

If I do make a starter in the carboy, should I use an airlock or just the foil covering?


Many, many thanks. Seems like the more I try the more freaked I get. I used to just toss the smack pack in in a 5 gallon batch. Last time I did 10 gallons I just made a single 2 liter starter and split it among 2 carboys.

After a little more research at Mrmalty I think I'm going to make a 2l starter tonight, split it, then pitch into two sanitized carboys with 2 liters of starter each tomorrow.

What do you think?

You have to step up. The yeast will throw it right at the edge of the plate away from you and you'll strike out everytime. :cross:

Sounds like a good plan.

I like the calculator on mrmalty.com. I usually decant my starters, but you certainly don't have to. If it's convenient to do it the way you suggest, I think it's a good plan!

Been doing starters in my buckets....for years.
Why dirty a flask?

I will never primary in a BB or carboy again.

I know what goes on, I don't need to see it anymore. Cleaning krausen out of a narrow mouthed vessel SUCKS.

You may want to make sure you don't add the wort too hot to the carboy - that was my concern when I thought of the same idea. If you can't get the temp to pitch you risk killing your work and adding another step while increasing risk of germ-ies

I think I'm going to boil the wort starter and chill it in the pot, then add to carboy. That way I can check temp before pitching yeast.

I'm undecided, though. I have a gallon milk jug (plastic, unfortunately). If I clean and sanitize, I was considering chilling the yeast, decanting, and pouring the yeast into 4 quarts of wort in the milk bottle.

Anyone use a plastic milk bottle. Definitely ghetto, but I'm weirdly concerned about starters in the carboy for some reason. I think I'm just used to sanitizing those right before putting my wort in them.

Well, now I'm thinking I'll put the starter in the freezer for a bit tomorrow to get the yeast to flocculate, decant it, then add another 2 quarts of wort to it. This may underpitch by about 1 liter, though. What do you think?

I'm reading so many posts about how crappy the "beer" in a starter is. On my last 10 gallon brew I pitched the whole thing. It fermented fine, but I felt like there were some off flavors.

I'm curious about this method myself.

I'm about to do my first lager, and according to MrMalty it requires a 2.6 gallon starter. Since I've got a fermentation fridge, would it do any harm to make the starter at 50 in the carboy, crash it at 34 for a few days once it finishes out, and just siphon off (and maybe drink) the proto-beer prior to bringing it back to 50 and pitching?

Considering the surface to air ratio when using a carboy, I don't think you would have to shake too much. You should get plenty of oxygen diffusing into the starter.

I will be trying this method when making my RIS. The OG is 1.10 so I need a big starter.

For doing stepped starters This calculator will make your life much easier, it gives the same results as Mr. Malty, but it's built for stepping.