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What are the practical effects of mashing too low?

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Podo:
A couple weeks ago I made an Irish Red.  I was supposed to mash at 153 degrees, but I forgot to preheat my mash tun (sitting in my cold garage), and I got busy and didn't check the temperature while it mashed.  After an hour, I opened it and the mash was sitting at 141 degrees.  At that point, I didn't bother to see if it had converted, I just brewed it anyway. 

Can anyone predict how it might turn out?  I assume it will be very thin bodied, at least, but I wonder if it will even taste remotely alright.

Kaiser:
When you mash at a lower temperature the conversion process takes longer and may not complete in the 60 min that most of us give the mash. The result is lower efficiency and possibly unconverted starches that can give the beer a starch haze. If your mash temps are substantially lower (140 and lower) starch doesn't gelatenize and the conversion process takes much longer since the enzymes have to chew away on the outside of the ungelatenized starch granules. At this point you would have substantially lower efficiency.

Another effect is that enzymes like b-amylase and limit dextrinase survine much longer and are thus able to produce more fermentable sugars. The resulting wort will be more fermentable and the finished beer can end up thin and lacking body.

Kai

ndcube:

--- Quote from: Kaiser on December 09, 2009, 09:37:56 PM ---Another effect is that enzymes like b-amylase and limit dextrinase survine much longer and are thus able to produce more fermentable sugars. The resulting wort will be more fermentable and the finished beer can end up thin and lacking body.

--- End quote ---

Like my Belgians!  :)

nyakavt:

--- Quote from: Kaiser on December 09, 2009, 09:37:56 PM ---When you mash at a lower temperature the conversion process takes longer and may not complete in the 60 min that most of us give the mash. The result is lower efficiency and possibly unconverted starches that can give the beer a starch haze. If your mash temps are substantially lower (140 and lower) starch doesn't gelatenize and the conversion process takes much longer since the enzymes have to chew away on the outside of the ungelatenized starch granules. At this point you would have substantially lower efficiency.

--- End quote ---

A couple of online sources I've read say that barley starch gelatanizes between 147 and 153 F (64-67 C), but it can vary up to 10°C depending on factors like crush, modification, water to grist ratio, etc.  Ungelatanized starch has the consequences that Kai states above.  Based on my anecdotal experience of taking mash gravity readings on the last half dozen batches, just about any beer mashed in at or below 152 has not completed conversion in 60 minutes.  This is always remedied by raising up above 155 for a very short amount of time, maybe 5 min.  I theorize that ungelatinized starch is the main culprit, not sluggish enzyme activity, but either problem has the same solution.

dean:

--- Quote from: Kaiser on December 09, 2009, 09:37:56 PM ---When you mash at a lower temperature the conversion process takes longer and may not complete in the 60 min that most of us give the mash. The result is lower efficiency and possibly unconverted starches that can give the beer a starch haze. If your mash temps are substantially lower (140 and lower) starch doesn't gelatenize and the conversion process takes much longer since the enzymes have to chew away on the outside of the ungelatenized starch granules. At this point you would have substantially lower efficiency.

Another effect is that enzymes like b-amylase and limit dextrinase survine much longer and are thus able to produce more fermentable sugars. The resulting wort will be more fermentable and the finished beer can end up thin and lacking body.

Kai

--- End quote ---



Wow!  Short and sweet reply.  I think you answered a lot of my own questions about some problems I've had from time to time, thanks Kai.   8) 

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