does malt choice influence clarity?

I've been working hard this year to nail down a few original recipes, one of which is a late-hopped american amber, which I load down with a german-style malty bill.
I brewed it first a while back and it came out wonderful, and very very clear red. I got many comments on the quality of this brew and especially the appearance. I cold-crash alot, use whirlfloc, and do what I can pretty much the same way every brew.
Anyway I brewed this beer again with an adjusted malt bill and its now coming out of the keg alot hazier than the first go around.
I must figure out what I did so right to give me such good clarity.
Would the different malt bill have made the difference?

1st amber - very clear - 53% Vienna, 26% Munich, 10% Crystal60, 10% Pale 2row

2nd amber - hazy - 43% Munich, 30% pale 2row, 17% Vienna, 10% Crystal60

My hopping was about the same, and yeast choice was the same both runs.

It doesn't seem likely to me that these ingredients influenced clarity, but I really tried to keep everything the same. Well ok, only other difference was 2 degrees higher on the 2nd mash.

Cheers!

I don't see any reason for a change in the clarity. Maybe you didn't get as good as a cold break in the second batch?

I had a smooth chill both times, without incident according to my notes.

Ok, according to my notes I made a big boo-boo on the second run.

Does pitching temp affect clarity? I used notty both times, with fermentation in the low 60's. First run I pitched @ 61 and let it ramp a few degrees. Second run I pitched @ 70, let it chill quickly to 61 (it went from 70 to 61 in the time between pitching and start of krausen), and then let it ramp again similarly.

Not really...

Hell I pitch in the 80's on occasion. My fridge takes FOR-EVAR to bring something down to temperature (12 hours or so), so once I get the yeast and the wort within 10 degrees or so of each other (yeast at 72-ish, room temperature, wort low 80's) I pitch it, and figure that the wort will cool off slowly. By the time I hit krausen, the temperature is dropping down to where I let fermentation happen.

I've noticed with several yeasts the recommendation on the package is to pitch warm, and then cool down once signs of fermentation start. I always have vigorous fermentation within about 12 hours with this method, and considering that I usually forget about... err... I mean "bulk age" my beer for about 3 weeks on the yeast cake, I get very, very clean fermentation. In fact, I get constant comments about how clean and subtle the flavors of my beer are.

Anyway, my first two suggestions are to cool your wort faster to get a better cold break. If you have an IC or CFC, consider a cheap pump from harbor freight or the ilk and run icewater through it. Seriously, the time of day can alter the water temperatures you're running through your chiller, and change the cooling time. I either try to brew in the morning or aim to finish up with my chiller late at night, so the water I'm running through the chiller is n ice and cool. I've literally noticed a 20 degree difference in water temperature throughout the day, and that *will* have an impact on your cold break.

Second, have you let your hazy beer sit in the fridge for a week or two? Chill haze, I've discovered, will settle out after a week or so in the fridge and will actually improve the clarity.

I think I've got a real handle on cold break, Theflatline. I use a copper 50' immersion chiller on full blast in my 6 gallons of wort, and it gets to the 70's within 10-15 minutes. Usually when the temp hits 95-100 I switch to pumping ice water with a sump pump. I also manually whirlpool during the chill.

I am drinking this pretty fresh out of the keg, and it hasn't chilled at my keg temp (40-42) for even a week yet. Maybe I should just be patient and let it sit.

I do have a better idea on how to completely strip my wort of cold break and hop trub before pitching. I will be testing the idea on my next batch. I'm not sure if this will improve clarity but its worth a try.

I plan to start my siphon from the kettle into my fermenter. After a couple of gallons of crystal-clear wort from above the pile of trub, I will attach my siphon tube to a clean keg beverage out post and continue filling the keg, emptying the entire kettle trub and all into the keg. Then chill keg and let break/trub settle. Hours or a day later I will pressurize to 5-10 psi and pump out the break/trub. Once clear I will pump via BMBF-style attachment into the fermenter with the rest of my clear wort and pitch.

The reason to partially fill the fermenter first is to make sure I can get the full 5.5 gallons into my fermenter, due to the keg limit of 5 gallons.

I know I'm giving myself suggestions.. but let me know if this is a bad idea. Trying to eliminate some factors and get some consistency. Eliminating trub seems like a good idea and worth the trouble.