excessive activity

I'm doing a yeast starter that started with 4.2 oz. of muntons pale DME and H2O to make one liter and one packet of Wyeast 1056. I'm using a 1/2 gallon growler to hold the mixture.

The first fermentation period went pretty much as expected. Some bubbling in the airlock and a small krausen layer on top that dissipated after 24 hours or so. After 48 hours, I put the starter in the refrigerator for 8 hours and then decanted a majority of the liquid off the top of the yeast.

I then made another 1 liter solution of DME/H2O to step the starter. This one is bubbling like crazy, the krauzen layer has completely filled the void and has overflowed the airlock several times. I've never seen this happen before.

All-in-all, the yeast starter smells good and I've been careful with sanitation. I boil the DME/water for 10 minutes prior to cooling it down and sanitize all other items with Five Star Io Star.

Does anyone suspect a problem with this yeast that would warrant me starting over again prior to the actual brewing (currently set for Sunday)?

Some fermentations are active, some are boring. Some you have to make a blow off tube, others you never see an airlock bubble...it really means nothing.

No, this has happened to me before as well. Have you stepped up a starter before this? When you step up, you're adding wort to an already magnified level of yeast, and that excessive activity is very common. Just clean up the mess and recover. I got tired of doing this and have been adding one drop of FermcapS to my starter wort.

Also, from what I read on here, it's best to not use an airlock on your starter. Rather, use a piece of sanitized aluminum foil over the top. The airlock will block any O2 from getting in. For your beer, this is recommended to prevent oxidation. For a starter, you want O2 to get in to help the yeast replicate/multiply. For the volume of your yeast starter wort, you won't taste the effects of oxidation in your finished product.

Thanks for the help! This is only the second starter that I have stepped up, so didn't have much personal knowledge to rely on. FermcapS sounds like a great idea.