boiling grains / decoctions / question

[Tourist]

An off-topic question for DrSmurto (G'day mate) and others:

Don't you boil the crap out of grains when you do a decoction? If answer = yes, why don't we worry about tannins when we decock? I'm not taking the piss, by the way - an honest question, sorry for going OT.

[gregb]

I spun this out of this thread, it is an interesting question that is worthy of thread of its own.

Cheers,
Greg

[warra48]

That's a common question, but the answer is that you don't extract the tannin when boiling decoctions.

Boiling is not the only factor, the pH of the mash must also be conducive to tannin extraction, and that's not the case with a decoction.
Decoctions tend to lower the pH of the mash by about .1 to .15pH units.

[Kevnlis]

Warra is correct, pH is the major factor. Length of boil and the amount of liquor in the grist (how stiff, or free of grain the boiled mash is) have a large impact on this as well.

[Tourist]

Okay, so bringing us back to the thread this one was extracted from - if the fellow is directed to boil roasted grains, I would have thought this would lower the pH significantly more (gram for gram) than boiling pilsner malt. If "mash" thickness was an issue, surely you could just boil thick.

I still don't really see the difference. Happy to be enlightened.

[Kevnlis]

We are actually worried about the pH beig too high, not too low. Roasted barley is made with raw pearl barley which is huskless and therefore does not present the same set of problems as standard malts.

[Tourist]

Yeah Kev, that was my point - that the r.barley would theoretically lower the pH moreso than a paler malt, therefore reducing the magnitude of tannin extraction. Coupled with the fact that you have raised (and I didn't know before) that r.barley is huskless leads me to believe that boiling said grain is not such a bad thing (as far as tannin extraction goes).

Maybe the Brewcraft dude is not as "retarded" as others.

[Trough Lolly]

G'day, er, Tourist....

I don't know if the Burleigh Homebrew Supplies shop is exclusively a Brewcraft outfit - presumably not if they sell grains...

I'm still trying to work out what the HBS guy/gal was on about when they recommended simmering the 500g of Choc malt...and why 12 minutes???

FWIW, I don't have Choc malt anywhere near my stouts - pale ale malt, roasted barley and maybe some flaked barley and away you go. Less is more for a good stout's grainbill, IMO.

Cheers,
Bro Stout

[squirt in the turns]

Unfortunately I can't offer any answers regarding the instructions I was given. The guy didn't elaborate and I didn't ask (sorry - I was on a lunch break and in a rush). That 12 minutes did seem strangely specific (he may have said "about 12 minutes")

No idea if it's exclusively Brewcraft - he does sell a lot of their stuff.

[chrambo]

The contribution of unfermentable sugars from enzymatic and caramel malts can be increased by mashing at a higher temperature (i.e. 158°F) where the beta amylase enzyme is deactivated. Without this enzyme, the alpha amylase can only produce large sugars (including dextrins) from the starches and the wort is not as fermentable. The result is a higher final gravity and more body. (link removed) has some good links for this topic.. i found it very helpful

[Kevnlis]

The contribution of unfermentable sugars from enzymatic and caramel malts can be increased by mashing at a higher temperature (i.e. 158°F) where the beta amylase enzyme is deactivated. Without this enzyme, the alpha amylase can only produce large sugars (including dextrins) from the starches and the wort is not as fermentable. The result is a higher final gravity and more body. (Link removed)com has some good links for this topic.. i found it very helpful

Spam?

[Trough Lolly]

The contribution of unfermentable sugars from enzymatic and caramel malts can be increased by mashing at a higher temperature (i.e. 158°F) where the beta amylase enzyme is deactivated. Without this enzyme, the alpha amylase can only produce large sugars (including dextrins) from the starches and the wort is not as fermentable. The result is a higher final gravity and more body. (link removed) has some good links for this topic.. i found it very helpful

Yes, but my dear "chrambo", your somewhat, er, textbook response conveniently ignores the fact that ALL enzymes are denatured when you boil or decoct the grains. pH considerations notwithstanding, a decoction helps step up the mash temp and introduce additional melanoidins to the final product.

[Kevnlis]

If we want to ghet technical TL we could also tell him that the beta amalase is still active at the higher temperature. The majority will indeed be denatured, but I think you will find it can actually continue working at temps well above and below wht we normaly consider "optimal".