Boiling Grain For Flavour

[kevo]

I've always struggled to understand why boiling grains results in negative flavours, but decoction mashing(boiling grains - with husks intact) leads to reportedly positive flavours.

I'm not debating if the process of decoction works or not - it's the why I don't get.

Is it boiling the thick grains in a comparably dry state/the general absence of water in decoction?
Is it a pH thing?
Is it to do with enzymes being left in the main mash?

From what I've seen, it looks like an awesome process and the benefits sound as though they are worth the time/effort investment - just don't get how/why it works.

:huh:

Kev

 

[katzke]

Lots of old inaccurate info on the net. Some even in books.

There are sound rules for brewing. If you follow them you will be ok.

You can boil grain, however it is a very thick liquid that is boiled and only for certain styles of beer. Science in the thick liquid that keeps the bad stuff out.

Brewing is science and art. Some will say you can not steep this grain and others do it all the time. If you are an extract brewer, steep grain in hot water and boil the resulting wort with your hops and extract.

Cold steeping has uses. I would watch cold steeping for longer then a bit as you give bugs a chance to sour the wort. A hot process like drip coffee or a french press will give the same or better results in a few minutes.

No need to boil canned extract. If you are getting repacked liquid or dry malt then boil it. Dont believe me do the sugar test. Dissolve sugar in cold brewing water and let set on the counter covered. Then do the same in boiling water. See what sugar turns cloudy first. Have put the challenge out many times and never have had a response. I learned this from feeding Humming Birds. Extract like food should be treated the same. If in doubt toss it out, or boil it.

 

[Nick JD]

Is it a pH thing?

Yes. Barley husks have tannins (astringent, dark coloured compounds) that are drawn out at high pHs with heat. At a pH around 5, they are mostly left in the husk.

However, protein compounds in the boiling mash join up with sugaz to form melanoidins via the mailard reaction (a type of caramelisation). These taste marvelous - very malty and sweet, and dark brown, and balance beautifully with a LOAD of noble hop bitterness to get that bittersweet decoction flavour in pilseners and a toasty bun sweetness in weisses.

 

[pcmfisher]

Dont believe me do the sugar test. Dissolve sugar in cold brewing water and let set on the counter covered.

Don't know about you, but when I make beer I don't just leave it on the counter to see if any bugs in it are going to start fermenting it.
I pitch some yeast in as soon as possible so it gets a hold before any other bugs that are floating around in your wort.

There are plenty of bugs in your wort whether you boil your dry malt or not.

 

[katzke]

There are plenty of bugs in your wort whether you boil your dry malt or not.

Mostly not true. There are lots of bugs in repacked malt and when you add water to make up wort you give them a big chance to get a real start on your wort.

By boiling the wort you kill the bugs and the only large amount of bugs that can get into the wort are from poor handling. Sure some get in when brewing as we do not brew in a clean room. The few that do get in are much less then those that are given a chance to get a good start by not boiling.

Given the choice, I will boil anything I add to my hard earned wort. From repacked malt to priming sugar. Notice I say repacked malt, not canned extract. Priming sugar is dirty as well as dry malt and repacked extract. I am offered repacked liquid malt here in the USA. Comes in a plastic tub with snap on lid. I have seen how they pour it out of a barrel and it is not clean like canned extract. Grain, who knows what has been in it?

We do extra steps to make sure we have as few bugs that can get in our wort and beer. Why would you not boil repacked extract to kill all those bugs that are in it?