Mash out causes haze?

I made czech pilsener and it turned out to be a bit hazy.
Mashing sheme was like this:

dough in 75*C
1 hour in in 67*C
mash out 76* by infusion of 7L boiling water.

A friend of mine says, that adding rapidly boiling water to wort can cause this haziness. What do you think?

I never heard that before. I can't imagine it to be true, otherwise all decocted beers would be hazy as well as any beer step-mashed with boiling water infusions. It could be that you needed a protein rest. Do you know how well modified the malt is?

I like protein rests with Pils malt since it's typically less modified than pale 2-row. 131*F for a few minutes does the trick, I just do a double infusion.

Protein rest? Maybe. I usually do it with pilsner malts, but I discussed about it with Kaiser here on the forum and we agreed that this malt doesn't require protein rest (Weyermann Pilsener Malz).
https://www.homebrewtalk.com/f36/doughing-about-room-temperature-74586/index2.html

I have a german pils fermenting; made with the same mashing scheme, same malt, we shall see how it will turn out.

Yeah, Weyermann shouldn't need it and, depending on protein rest temperature, could be worse for having it. Not sure what caused your haze, but it wasn't the mash out w/ boiling water. What was your water to grain ratio?

menschmaschine said:

Not sure what caused your haze, but it wasn't the mash out w/ boiling water. What was your water to grain ratio?

Click to expand...

1kg : 2.2 L, pretty thick.

german pils 5.44 kg
carapils 0.34 kg
acidulated 0.10 kg

to 13L of water

Maybe too much of acidulated malt (~3.5 oz) ?

The only reason a mashout would cause haziness is if your conversion is not complete when you do the mashout. The mashout will slow/stop the conversion process leaving starches in the beer. Ofcourse you shouldn't be spargin at that point either but without a mashout the wort will have a considerable amount of time during the sparge and heating before the boil to finish the conversion.

Craig