[dzlater]

I am planning on brewing this http://barclayperkins.blogspot.com/2011/01/lets-brew-wednesday-1811-whitbread.html
It calls for a 2.5 hour mash.
I am assuming this was done because of the poor malt quality of that era.
Would it really make a difference if I just mashed for my usual 1 hour?

[euge]

I don't see why not. If you want to stay true to the recipe then mash the full amount of time.

[tubercle]

The Tubercle has mashed overnight with no ill effects.

[majorvices]

With today's malts a 45-60 minute malt is perfectly adequate (20-30 minutes in many cases) - but a longer mash won't hurt and may increase you efficiency if you can keep the temp steady. If the temp drop lower for an extended period you could get a drier beer than intended. I don't think that enzymes get denatured very quickly at mash temps.

FWIW I mash my tripel for 90-120 minutes and get very high efficiency. Or, at least a few points higher than normal.

[jamminbrew]

Wouldn't a conversion test with iodine tell you whether it's done in the mash or not?

[denny]

Wouldn't a conversion test with iodine tell you whether it's done in the mash or not?

Maybe.  It's fairly easy to get a false reading with that test.  It also doesn't tell you how far things have gone.

[Thirsty_Monk]

I also do not do the iodine test.

There is a conversion table to check your mash OG.
Thinner mash lower OG.
This seams to be better then iodine test.

[a10t2]

There is a conversion table to check your mash OG.
Thinner mash lower OG.
This seams to be better then iodine test.

That just tells you that you've solubilized the starches, though, not that they've been converted.

[Thirsty_Monk]

There is a conversion table to check your mash OG.
Thinner mash lower OG.
This seams to be better then iodine test.

That just tells you that you've solubilized the starches, though, not that they've been converted.

Not to be argumental but if I check OG with refractometer I get reading of sugar in solution.
It does not mater if I take sample from Mash tun of boil kettle.
Refractometer reads sugar and not starches.

It least that is my understanding of it.

[a10t2]

Refractometer reads sugar and not starches.

I've actually checked a cornstarch solution and it does result in a reading on the refractometer.

[johnf]

There is a conversion table to check your mash OG.
Thinner mash lower OG.
This seams to be better then iodine test.

That just tells you that you've solubilized the starches, though, not that they've been converted.

Not to be argumental but if I check OG with refractometer I get reading of sugar in solution.
It does not mater if I take sample from Mash tun of boil kettle.
Refractometer reads sugar and not starches.

It least that is my understanding of it.

You get a reading of everything in solution with the (incorrect) assumption that it is all sucrose, assuming your refractometer is calibrated for sucrose.

Cornstarch is poorly soluble in water so I would expect the refractometer to read similarly in water and a water/corn starch suspension.

[Thirsty_Monk]

Interesting.
I was referring Kai's article about this matter but his site seams to be down.

[Bret]

The Tubercle has mashed overnight with no ill effects.

Bret has done this, too.