Have a question on this Kolsch Recipe

I stumbeld across the following recipe this morning:

All Grain Recipe - Kolsch ::: 1.048/1.012 (5 Gal)
Grain Bill
9 lbs. - Pilsner Malt (German if you have it)
1/2 lb. - Munich Malt (Light, 10L)
1/2 lb. - Wheat Malt


Hop Schedule (14 IBU)
3/4 oz - Northern Brewer (60 Min.)
1/4 oz - Northern Brewer (30 Min.)
- OR -
1.75 oz - Hallertauer (60 Min.)

Yeast
White Labs German Ale / Kolsch (WLP029) - 1800 ml starter

Mash/Sparge/Boil
Mash at 152° for 30 min.
Sparge as usual
Boil for 60 minutes
Cool and ferment at 65° to 69°


The mash time is only 30 minutes, that would tend to make the beer lighter correct? IE: extract more fermentable sugars but less body....

dpalme said:

The mash time is only 30 minutes, that would tend to make the beer lighter correct? IE: extract more fermentable sugars but less body....

Click to expand...

You only need to mash long enough to get conversion. But in a 30 minute mash, you may or may not be fully converted. If you're converted, that's fine. If not, there will be a ton of starch in the finished beer.

A very short mash usually works with a high temperature mash, as a warmer temperature mash will convert faster. A 30 minute mash will NOT make the body lighter- just the reverse is true. There will be less body and a drier finishing beer from a longer, cooler mash.

Yooper said:

...............A 30 minute mash will NOT make the body lighter- just the reverse is true. There will be less body and a drier finishing beer from a longer, cooler mash.

Click to expand...

Correct!!!! Shorter mashes typically results in a higher final gravity and a longer mash will typically give a lower final gravity (everything else being equal).

What typically is meant by fully converted is that the mash now gives a negative starch reaction with iodine. This means that largest chains or starch have been broken down into smaller chains, HOWEVER, some of these can be quite long, but are short enough to not react with iodine. Some of these are not very fermentable. With additional time, the amylases continue to chew up the dextrins into smaller and smaller pieces, ultimately down to maltose (glucose-glucose).

If you mash high, you have lots of alpha amylase activity which is great and fast at breaking up big chains into smaller chains (iodine negative). It is much slower at making maltose. If you mash out early you will have more longish chains which will not ferment out, resulting in a higher final gravity. Even though you've measured full "conversion"

If you mash cooler, the alpha amylase is less active so breakdown on the big iodine positive chains is slower, but now you are in the range where beta-amylase is still active (it is less heat stable than alpha amylase). This enzyme quickly attacks the ends of any dextrins (large or small) to produce maltose. So when you mash cooler, you get more maltose production which typically with the result in a lower FG beer

dpalme said:

The mash time is only 30 minutes, that would tend to make the beer lighter correct? IE: extract more fermentable sugars but less body....

Click to expand...

I don't think this is a good recomendation since there is no way to really know where in the proces you are as different grain will convert at different rates.

I say go for a full conversion!

If you want a malty beer mash at a higher temprature. OR Add some Dextrine malt

If you want a crisper more alcoholic beer, a lower temprature.

You will have more control over your brewing this way.

DPB

All my mashes have been 60-90 minutes, including one that I ended up mashing at a lower than called for temp but yielded a pretty good light bodied beer.