would a beta-glucan rest help with high-rye beer?

[beargrylls]

I tried brewing a 70% rye malt "ryewine" yesterday. 4.25 kg rye malt, 2 kg pale malt, 0.8 kg rice hulls. The wort was super syrupy. I mashed at 65 C (149 F) for 60 minutes, single infusion. I was wondering if a beta-glucan rest before the sacch rest would have helped to reduce the viscosity of the wort??

At the end of the boil I had 15 L of 1.080 wort that had the consistency of cough syrup.

 

[RM-MN]

That's what a beta glucan is for. It breaks up the sticky "glue" of the beta glucans.

 

[bbrim]

A beer like that is the only time I would use a beta glucan rest. I also don't think I would try such a high percentage rye without one. It sounds like you did okay without one, I think any 1.080 is going to be a bit syrupy. Hopefully the beer comes out to your liking!

 

[VladOfTrub]

Beta glucanase is usually kilned out and if any remains it is very little. Raise the mash temp up into the proteolysis range. The enzyme will break down beta glucan, converting it to glucose, thereby reducing mash viscosity.

 

[sudbuddy]

That much rye is gonna make an oily beer no matter what, but a beta glucan rest should help

 

[Natdavis777]

The only time I step mash is when using rye. Def try it next time

 

[VladOfTrub]

A beta glucan rest with rye is futile as it contains no beta glucanase, niether does modern malt. If a beta glucanase rest is employed, the enzyme, beta glucanase is added. The only enzyme left in the rye, which will reduce beta glucan, is proteolytic enzymes, because the enzyme survives kilning.
The beer is going to turn out horrible, the mash will be a sticky porridge of goo. The rye should have been boiled until it "broke" and then a proteolysis rest employed. If beta glucanase is added, a low temperature rest in the beta glucanase range would be valuable. The other issue with rye is that it is loaded with alpha and alpha creates non-fermentable sugar.
I'm not sure what is accomplished by doing a beta glucanase rest. Especially, since the malt doesn't contain it.
Sometimes, it is not a bad idea to look at a malt data sheet. That way, you'll know what is in the malt that you are dumping hot water on.

 

[beargrylls]

hmm interesting thanks for the replies. i have also been told that a high concentration of pentosans in the rye malt is a significant contribution to the oily/sticky/cough-syrupy viscosity of the wort. are there any enzymes that can break down pentosans in the mash?

 

[RM-MN]

I find it interesting that both John Palmer in "How to Brew" and this article in MoreBeer (http://www.morebeer.com/articles/advancedmashing) both say to do a beta glucan rest to break down the beta glucans while VladofTrub says there isn't any beta glucanase to do that work.

Another article in BYO says to do the rest too. (https://byo.com/stories/item/1497-the-science-of-step-mashing)

 

[RM-MN]

As I'm reading the forum and formulating responses I'm drinking a roggenbier with 66% unmalted rye in it. Yes, the mash was sticky and without the advantage of the bag in BIAB, I would have had trouble getting the wort out. However, the beer is anything but horrible but it is a strongly flavored beer. Here's the recipe I used. https://www.brewtoad.com/recipes/real-roggenbier

BTW. I did not do a beta glucan rest although I probably should have and with the unmalted rye the beta glucanase would have been present.