How do you know if your starter is infected?

I made a starter with WLP007 Dry English Ale yeast. I Sanitized EVERYTHING! 1 cup light DME to 2 pints (32oz). Boiled 15 minutes, cooled, pitched and put on a stir plate. The yeast expires 8/12. I've never used this yeast before and only have about 3 starters under my belt. My question is, how do you know if its infected? The reason I ask is because the yeast looks "chunky." Not off color nor does it look anything like the krausen of an infected batch of beer. When its being stirred it just looks like the yeast is clumped together in bigger than normal pieces, like small cottage cheese bits. I've never experienced this before because all of the other starters I've made have swirled into a smooth looking solution until I pull it off the stir plate and the yeast settles at the bottom. Am I just paranoid, and this is how english ale yeast appears? Or Do I have something seriously wrong with my starter?

I hope the picture will help, but its tough to see while being stirred because the yeast settles out when I turn the plate off.

looks normal to me. i've had chunky yeast in starters before.i have a two litre starter of 1098 going right now that's super chunky. taste and smell the wort when you decant, if it's not fouled, i'd say you're good to go.

That's normal. I remembered the first time I used that yeast from white labs, it was only a quarter or 1/3 full of the white labs vial. I asked the LHBS what was up with that, and different strains have different characteristics.

WLP007-dry english ale is chunky.. Check out the Youtube video:

[ame=http://www.youtube.com/watch?v=Xd8wji3hEVA]WLP007 - the Dry English Ale yeast starter for the Coconut Porter All Grain Recipe - YouTube[/ame]

This yeast tends to have violent fermentation in the primary especially if you have a good size starter from my experience.

It wouldn't hurt having a blow-off tube.

Thanks Lito. Exactly the answer I was looking for. I was already prepared with a blow off tube. My bitter Chocolate Oatmeal Stout had an O.G. of 1.096 and is fermenting at 75F. Needless to say, It's going nuts!

What they said. A lot of the British strains are chunky.

A nice thing to do, if you decant that before pitching the slurry, is to drink some of the starter. It really gives you a sense of the flavor that the yeast is contributing.

The only infection I ever witnessed in my amateur brewing career was in my pacman starter, RIP. I kept shaking it and taking the lid off, and left it out maybe 2 days after fermentation was done. Too long....

The smell was slightly foul, and there were white stringers going across the top of the fermented starter.

Look how chunky Wyeast 1968 can be:


YouTube - VID-20110811-00006.3GP

Looks like egg drop soup!

MC