Interesting Beer Club Meeting Last Night On Mashing

So I went to my local beer club meeting last night with the topic being on mashing. Two things really stuck out at me and just wanted to throw them out there for people to discuss.

1) The typical standard time for a Sach. Rest is 60 minutes, but professional brewers say that with well modified malts, full conversion can actually take place in as little as 5 minutes. The consensus was that if your using a recirculating system, you're ready to move to mash out temps once your wort starts to run clear i.e. clear wort means full conversion of the malt has take place. A 60 minute rest won't hurt anything, but it's not necessary.

2) I've been sparging for 1.5 hours to reach where my OG should be. This is too long and is probably leading to some astringency entering my beer. I should probably be shooting for 1 hour.

BVilleggiante said:

1) The typical standard time for a Sach. Rest is 60 minutes, but professional brewers say that with well modified malts, full conversion can actually take place in as little as 5 minutes. The consensus was that if your using a recirculating system, you're ready to move to mash out temps once your wort starts to run clear i.e. clear wort means full conversion of the malt has take place. A 60 minute rest won't hurt anything, but it's not necessary.

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I don't know, but wouldn't an Iodine test confirm the conversion?

I would agree with both of those points. I recirc mash for an hour but I'm sure it's converted well before that...

I rely heavily on Iodine test, and give it another 10-15min for good measure after positive conversion test. I have been getting a positive Iodine test for conversion using Maris Otter (my base for 75% of recent beers) at around 30-40 min with recipes only using grains and no adjuncts (oats, corn, sweet potato, etc). If I'm busy getting other things ready I'll still let it ride to 60 min, it won't hurt anything.

1.5 hours is a LONG SPARGE. I fly sparge and I usually sparge for 45-60 min. time from mash tun to kettle approx 90min.

BVilleggiante said:

So I went to my local beer club meeting last night with the topic being on mashing. Two things really stuck out at me and just wanted to throw them out there for people to discuss.

1) The typical standard time for a Sach. Rest is 60 minutes, but professional brewers say that with well modified malts, full conversion can actually take place in as little as 5 minutes. The consensus was that if your using a recirculating system, you're ready to move to mash out temps once your wort starts to run clear i.e. clear wort means full conversion of the malt has take place. A 60 minute rest won't hurt anything, but it's not necessary.

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I have no clue if this is true or not, but if so, that means it's impossible to adjust one's mash temperature if it's not dead-nuts on at dough-in (for those of us who do not do a HERMS mash). That's scary.

I also know that those who adjust their mash pH tend to do it after a few minutes, and again, this seems to be almost impossible before conversion is complete.

Full conversion via the iodine test means there's no more starches left; it doesn't mean that the wort is 100% fermentable or is unchangeable. Most beer yeast can only ferment carbohydrates four sugar molecules in length, wine yeast three (Brett can eat 9-chain sugars, if you're curious). You can still have a lot of dextrins longer than this that won't register on an iodine test. Leaving the wort at mash temps will allow the amylases to continue breaking down these longer chains into shorter ones. Whether you want that to happen or not depends on the circumstances.

I think 5 minutes is too short. You will get some conversion, but you can probably get another doubling of your current sugar by going longer.
While most of the conversion is probably done at 15 minutes (say 70% of what you are going to convert, not 70% overall conversion), you will get more conversion going beyond that time.

Why on earth do you want to rush your mash? What is saving 15-30 minutes going to benefit you?
You are still spending hours on prep work, other tasks, and cleanup. Reducing 5 hours to 4.5 hours, at the risk of an insufficiently converted mash seems like a poor idea.

Plus, while the mash is going on, you don't need to be there. Go wash your car, or vacuum your house or get groceries.


The problem with the long sparge is the Ph rises and you are more likely to extract Tannins, that will lead to astringency in your beer.

I like to mash for 75 minutes or so. Mainly because I'm lazy.. Seem to get plenty good efficiency, and I can do a bunch of crap if I feel like it while it's sitting.

ArcLight said:

Reducing 5 hours to 4.5 hours, at the risk of an insufficiently converted mash seems like a poor idea.

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This. I personally don't try to find ways to save time. I like the process and during the mash I can get a lot of things done to prepare for the remaining brew process. If there is a little inefficiency in my process, so be it.

1) 5 minutes sounds a bit short. 15 minutes perhaps, but I'll still do my 60 minute mashes, thank you very much.

2) Gauging your sparging by the clock is odd. Look at volume, s.g. of the runoff, and ph in the tun. Thats what matters.

To save time:

1. 5 minute mash

2. NO boil, just pasturize your wort at 165 for a bit

3. No Chill, straight into a No Chill cube (plastic Jerry Can). You can get your hops from a hops tea you make on the side.

You can have a 1 hour brew day (5 minute mash, 15 minute pasturization, 30 minutes to heat the mash water)
The next day, pour it into the fermentor, add yeast and ....

I wonder how it comes out


(the No Chill will work, I dont know about the other 2 points. Since there is no boiling, there is no DMS, right? I wonder how it would taste?)

ArcLight said:

To save time:

1. 5 minute mash

2. NO boil, just pasturize your wort at 165 for a bit

3. No Chill, straight into a No Chill cube (plastic Jerry Can). You can get your hops from a hops tea you make on the side.

You can have a 1 hour brew day (5 minute mash, 15 minute pasturization, 30 minutes to heat the mash water)
The next day, pour it into the fermentor, add yeast and ....

I wonder how it comes out

(the No Chill will work, I dont know about the other 2 points. Since there is no boiling, there is no DMS, right? I wonder how it would taste?)

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Someone's had a beer or ten. ;-)

You could just put the grain and hops in the mash water before you heat, kill the heat at 170 and start draining immediately. I'm good with a 45-60 minute mash, it gives me time to get the rest of the brewing equipment ready, walk the dog, or play on HBT.

Conversion does happen quickly, 15-20 minutes, the remaining time is making tea, extracting flavors and color. I mash until my calculated conversion efficiency exceeds 90% based on periodic refractometer readings. Kai has a good table for helping to figure out the maximum conversion value.

If you can get your hands on the September 2011 issue of BYO, there is an article called "When is my mash done?" that tackles this very question. The magazine and James Spencer from Basic Brewing Radio do a "collaboration experiement" with a number of other brewers to try to answer the question. Alternatively (or in addition to), you can listen to the episode of Basic Brewing Radio where they talk about the results of the experiment with different mash time lengths and explain why, even after a positive iodine test, it is good to let the mash sit. Here's the link:

http://www.basicbrewing.com/index.php?page=basic-brewing-radio-2011

Download the one from February 10, 2011 entitled "Mash Time Experiment." Here's the description:
Home brewer Charles Hoffman and James conduct an experiment comparing the effects of different mash times on a single recipe. Chris Colby and Kai Troester help interpret the results.