Starter foamed over. Is it no longer sanitary?

[homebrewflyfish]

Hi all,

I had some questions about my starter in a previous thread but now I have a new issue.

I stepped up my starter with 1L of water and 2 cups DME (I'm going for a big beer so wanted to give them a close OG to propogate) and was getting a great fermentation in my half gallon mini-growler.

I don't have a stir-plate, but after reading some of the posts and articles, it seemed like I should aerate it more. So I gave it a few stiff swirls. Bad idea. I had the twist top loosely on, then that covered with plastic wrap secured by one of the gf's hair ties (work great in place of rubber band btw). Well it foamed straight out through all of it.

So I had to clean it up, wipe down the bottle, and replace the plastic wrap. It seems to be all good and is fermenting away still and a great layer of yeast it building up. But I'm concerned that the wort bubbling over could have produced a way for nasties to get in there. I know if you cover it, airborne contaminants have a hard time getting in. But can they 'crawl' back up through the foam to get in? Is there a chance it's no longer sanitary?

Please give me some advice because I don't want to pitch an infected starter to my brand new beer.

Also, just wondering how much yeast you might lose to a blow off like that?

Thanks everyone.

 

[shot0rum247]

Yeah....shaking a starter after fermentation starts is a bad idea. You definitely want to do that before pitching your yeast. Stirplates are not necessary just helpful, dont worry if you dont have one (i dont use one). When the starter is active just swirl it around every hour or so that your awake. As far as contamination goes, you are really the only one that can answer that. If your area is clean and the starter still smells like good fresh yeast, then your probably good. If you sense an off odor get some new yeast. If your wort is already ready to pitch and you need yeast in a hurry, pitch a vile of whitelabs without the starter. Hope this helps!

 

[homebrewflyfish]

Well I gave it a shot. I brewed what is my interpretation of a DFH 90min clone. Everything was going well except a couple of weird things happened...

First, I put my starter in the fridge to clear. Problem is fermentation was not over, so I'm wondering what kind of torture I just put my yeast through. Oddly, on top of the nice white yeast layer that had been forming settled a brownish layer, then another thin white layer.

What is the brown layer? Infection? Hurt yeast? I'm worried because of the foam over that happened.

Then, before I pitched it something crazy happened. While it was sitting on the counter, the yeast cake started rising in little stalagmites. It was very odd, these little white towers of yeast crawling to the service (wyeast 1098 brit ale btw). And it was bubbling pretty good again, another sign it wasn't finished in the first place. I probably should have waited another day or two to brew, or just pitched everything without decanting but I didn't want to put that nasty starter wort in my beer.

Then, halfway through my 90 mins of boiling, my gf gets some kind of food poisoning and needs my attention. So I'm running back and forth between the pot and helping her for the next 2 hours. Of course right when she needs me the most is when I'm pouring my wort into the fermenter. It was a crazy 10 minutes and I'm not confident I didn't do something stupid. Plus it took me longer than normal to seal up the fermenter, and it was exposed for longer than I like.

But in the end I decanted off about half the starter wort and pitched what was in there. I'm not confident about it because I feel like I screwed up the starter something fierce by refrigerating it too soon. Plus, the craziness of the whole thing with the gf. Oh well, we'll see what happens.

At the very least this was my first mini-mash and it worked out. I hit my target 1.090!

 

[homebrewflyfish]

Wooweee! Bubbling like crazy this morning. Definitely my strongest fermentation yet. It's 5G in a 6.5G ale pale and its bubbling out the airlock after only 12 hours!

So hopefully it's nice happy yeasties farting it up in there and not something nasty.

 

[Evan!]

First, I put my starter in the fridge to clear. Problem is fermentation was not over, so I'm wondering what kind of torture I just put my yeast through. Oddly, on top of the nice white yeast layer that had been forming settled a brownish layer, then another thin white layer.

What is the brown layer? Infection? Hurt yeast? I'm worried because of the foam over that happened.

It's just trub. No worries there. The foam-over didn't hurt anything...you have positive pressure pushing out of the vessel, so the chances of foreign bacteria/yeast "swimming upstream" and finding their way in there are very minute.

Then, before I pitched it something crazy happened. While it was sitting on the counter, the yeast cake started rising in little stalagmites. It was very odd, these little white towers of yeast crawling to the service (wyeast 1098 brit ale btw). And it was bubbling pretty good again, another sign it wasn't finished in the first place. I probably should have waited another day or two to brew, or just pitched everything without decanting but I didn't want to put that nasty starter wort in my beer.

First off, if you account for the malt extract from the starter in your recipe calcs and volume, you can add the whole starter (it's not "nasty") and not have any problems. Regardless, those "stalagmites" are nothing but dissolved CO2 coming out of solution as the liquid warms up. Don't worry about it. Next time, though, if it's not done fermenting, I'd just forget about decanting. It's better to have the extra cells.

 

[homebrewflyfish]

Thanks Evan! I was afraid that dark layer was dead yeast or something from being shocked. I'm looking forward to seeing how this one turns out.

 

[carnevoodoo]

I stepped up my starter with 1L of water and 2 cups DME (I'm going for a big beer so wanted to give them a close OG to propogate) and was getting a great fermentation in my half gallon mini-growler.

Just for future information, a starter is meant to be at a lower gravity than the beer you're making. The idea is to give the yeast an environment that is less stressful in order for them to multiply. By putting it in an environment that is close to the OG of the beer you're making, you're sort of defeating the purpose of making a starter. The yeast will have less strain because there was a smaller volume, but if you want more yeast, I would suggest stepping up your starter a bit at a time.

 

[homebrewflyfish]

Really? I thought I read that you should make your starter with conditions similar to what you were going to pitch it to. That way they wouldn't be shocked in a different environment.

I thought for sure I read that, but maybe they were talking about something else...such as ratio of fermentables to unfermentables? Or, maybe something else?

Clarification on this would help as then I'll just always shoot for 1.040. Thanks.

 

[shot0rum247]

You could have been reading about hops. People oftentimes lightly hop their starter to provide a similar environment in terms of acidity. I find that this is unnecessary.