I made a 1.5 mL starter using 6 oz of DME and tossed in my yeast early Saturday morning. For whatever reason, I woke up during the middle of the night and decided to look at the starter. The foam stopper was about 1/2 way off and yeast slurry was dripping down the side of the flask. There was yeast on the stir plate and on the walls. There was a really nice clean looking foam/krausen throughout the entire flask. I went and ahead and pulled it off the stir plant and placed the flask in the fridge to cold crash before today's brew day. Question being: do I need to really worry about contamination or should I be fine since yeast activity was very healthy? I will mention that I did have the stir plate at almost full velocity. I'd really appreciate some input. Id hate to have to dump this starter down the drain if it's contaminated!!
Assuming it was a 1.5 liter starter in a 2 liter starter? I'd use it. I'd sanitize the top of the flask with some Starsan. Try to wipe away from the center of the flask. When you want to clean the outside of the flask, just soak a terry cloth towel in some hot Oxyclean and drape it around the outside while you soak the inside. 10 Minutes later you should be able to rinse both sides clean. How does your yeast count look for your upcoming brew?
I did use a 2L flask. I guess I should have used my 5L, looking back now. It looks like I have about a 1/4" of yeast slurry on the bottom of the flask. It was on the stir plate for almost 24 hours.
If you use a defoamer in starters, this will never happen. No one knows if your starter is infected. Since the stopper didn't pop off all the way, it probably isn't infected. Tin foil is generally what most people use for starters instead of a stopper and air lock.
http://www.northernbrewer.com/foam-stopper-35-45mm That is what I use instead of a stopper and airlock. I guess I should just smell the yeast prior to pitching, and if it smells bad, don't use it?
Assuming you followed good practice in making your starter, the only potential for contamination comes from how you handled the starter container and stopper after the starter came out of the vessel. I always use a drop of Fermcap-S in my starters. This keeps them under control.
Yea thanks, lesson learned. My sanitation practices are very good so I'm not extremely worried. Before placing the stopper back into the flask, I sprayed it with starsan and pushed it down from the top. I think I'll be ok. We will see.
I had this happen a couple months ago during the second step of a 2 step starter. I don't recall the volume in the second step, but I want to say it was only 1-1.2L in a 2L flask. I was using WLP001. Within hours, it was overflowing as you described. I simply wiped the outside of the flask a few times and placed a paper towel between the flask and stir plate. I let it finish before cold crashing. Everything was fine.
This happened to me with a starter of 3787. Big blowoff just like you described. I just cleaned off the outside and replaced the foil and all went well.
I've had a few of these over the years with different strains of yeast. Never had an issue with infection. Just clean things up with Star-San and call it good. Always sucks to have to clean the stir plate after not noticing this for more than a day and the mess dries... I always use a flask twice the size of my starter for this very reason!
I've had a few blowoffs on my larger starters when using 001. It'll blow the foam stopper right off the erlenmeyer flask, but have never had an issue with infections or anything like that. The amount of krausen spewing out the top usually keeps anything from entering the starter. Use some saran wrap and lay it between the stir plate and the flask. Keeps the stir plate from getting gunked up
