Stirring during mash leading to heat loss?

[j_dawg]

So after a couple of years doing the all grain thing somewhat half-a**ed and especially lately making some severely underwhelming beers, I have finally started to put in the effort and get my system completely figured out and dialed in so I can get some consistency. I noticed a marked improvement with the last few brews by starting to pay closer attention to my mash temps.

However, one issue I am currently tackling is temp loss in my mash tun (3+ degrees with 5 gallon batches, 5+ degrees with 2.5 gallon batches), but I am wondering if the culprit might actually be user error. I generally do 60 min mashes (round cooler type with braid hose in the bottom to drain), batch sparging.

After heating and pouring my strike water, I stir for over a min then take the temp, and lately I have had my water/grain/temp calculations spot on and I hit usually within a degree of my target temp. So far so good, one issue solved, but over the course of the hour, I seem to lose quite a bit of heat. However, I do open the cooler and stir the mash every 20 mins. So, I know for a fact that I am losing heat this way. The question I am wondering is whether I need to stir at all during the mash (except at the end right before draining). I actually don't even know how I started doing the stir thing every 20 mins, I can't figure out where I read that, it just somehow became habit. Anyways, I still expect to lose some heat over the course of mashing, but if I could reduce the amount lost (especially on those 2.5 gallon batches) it would be great!

TLDR should I stop stirring every 20 mins during the mash?

 

[Yooper]

I didn't stir the mash when I used to use a cooler. I never noticed a drop in efficiency by not doing so, once it was stirred in thoroughly and the temperature was equal throughout the mash.

 

[Upthewazzu]

I've never stirred during the mash. Never even heard about doing it...

 

[Natdavis777]

I, too never stir. Never have. My cooler setup was a champ at maintaining temps. My now keggle setup holds great temps (with the assistance of Reflectix), but I still dont stir the mash after my initial stirring to hit my mash temp.

 

[Frilock]

If you've hit your temp, given it a good stir at the beginning, your conversion is mostly done by 20-30 minutes. To be fair, most of this 'OH YOU SHOULDN'T DO THAT' is really stuff thats not really going to hurt anything. If you lose a degree or two stirring every 20 minutes, but stirring every 20 minutes makes you feel better, keep doing it! Personally, I give it a good stir after I'm sure I've hit my temps. A good stir at 30 minutes before checking temps again, then a good stir at the end.

 

[beergolf]

I do not stir and really do not see the need to stir the mash. I stir at the beginning to get the temp stabilized and close it up. A good stir before draining and all is good. I lose about 1 degree per hour. No big deal.

I do get consistent efficiency so to me that is more important then trying to squeek and extra percent or two out of the mash.

 

[FirstAidBrewing]

Possibly a dumb question, but I can't quite tell from your OP, are you pre-heating the mash tun?

 

[wilserbrewer]

After heating and pouring my strike water, I stir for over a min then take the temp, ?

I have found that it takes longer than one would think for a mash to stabilize. After only one minute, the grain and strike water may not have equalized and you may be getting a false high reading, leading you to believe you are losing temp. I would suggest stirring well, covering the tun for a few minutes, then stir again very thoroughly till the temp is uniform throughout. Taking temp too quickly will give slight false high reading as the temp has not fully stabilized.

Stir twice with a few minute pause between, stir about twice what your intuition is telling you, then take a temp and leave covered for the mash rest.

Your second temp will be slightly lower than the initial temp....this is your true mash temp IMO.

 

[ArcLight]

I have found that it takes longer than one would think for a mash to stabilize. After only one minute, the grain and strike water may not have equalized and you may be getting a false high reading, leading you to believe you are losing temp. I would suggest stirring well, covering the tun for a few minutes, then stir again very thoroughly till the temp is uniform throughout. Taking temp too quickly will give slight false high reading as the temp has not fully stabilized.

Stir twice with a few minute pause between, stir about twice what your intuition is telling you, then take a temp and leave covered for the mash rest.

I agree. Doing BIAB (using my kettle to mash in) the temperature can vary a few degrees from spot to spot.

 

[MaxStout]

I agree. Doing BIAB (using my kettle to mash in) the temperature can vary a few degrees from spot to spot.

After the burner is shut off, there is still heat moving upward from the bottom of the kettle. I take a temp reading after the initial stir, then stir again in a few minutes. That second stir will usually yield a temp reading a couple degrees higher. It takes a little while to reach thermal equilibrium.

 

[wilserbrewer]

After the burner is shut off, there is still heat moving upward from the bottom of the kettle. .

Interesting, I'm electric and experience the opposite. Makes sense though....good point.

 

[j_dawg]

Possibly a dumb question, but I can't quite tell from your OP, are you pre-heating the mash tun?

Ok,so I failed to mention that in the post, but yeah, I am preheating the mash tun.

I appreciate the feedback everyone! I think next go around I will try not stirring it and see what my temps are like this time around. Got the water heating up already for an IPA recipe I have been working on, so I should hopefully be able to report back in a few hours.

I think the more confounding thing is where I read and decided to stir it every twenty minutes. I can't find that anywhere, it just randomly happened one day I just stuck with it for some reason

 

[wilserbrewer]

How are you preheating?

The correct way IMHO is to add water 10-15 over strike temp, and let it cool to strike temp and mash in. Others add a gallon or two of hot water....NG IMO.

 

[Natdavis777]

How are you preheating?

The correct way IMHO is to add water 10-15 over strike temp, and let it cool to strike temp and mash in. Others add a gallon or two of hot water....NG IMO.

This is my method. I heat my water in the BK, transfer to the MLT around 175F, add my brewing salts while stirring for a few minutes, and get the temp down to my dough in temp (usually around 162-164)

 

[wilserbrewer]

Sounds reasonable.

 

[brewbama]

I don't stir during the mash and I don't preheat my tun. I strike below the gelatinization point of the grain, then infuse boiling water to bring my temp up to my Saccharification rest temp, put the lid on and come back an hour later to mash out by infusing more boiling water.

 

[wilserbrewer]

I don't stir during the mash and I don't preheat my tun. I strike below the gelatinization point of the grain, then infuse boiling water to bring my temp up to my Saccharification rest temp, put the lid on and come back an hour later to mash out by infusing more boiling water.

Interesting approach, I like it....works well I'd imagine.

I think I will try this....two kettles, one mash and one with hot boiling and just ramp through mash and mashout....sounds very easily adapted to BIAB or batch sparging with a cooler. Could also be used to counter any temp loss in BIAB.

 

[j_dawg]

How are you preheating?

The correct way IMHO is to add water 10-15 over strike temp, and let it cool to strike temp and mash in. Others add a gallon or two of hot water....NG IMO.

I usually a gallon or so of hot water around 180 or so to my MLT, then drain that water before adding in grain and strike water. I just reuse the water I drained and gets reheated for the later sparge.

I managed to get two 2.5 gallon batches in a brewday yesterday, and though I only have two data points of not stirring so far, it seems some of the heat loss I was experiencing may have been due to stirring.

The first batch was an IPA recipe I have been working on, and I lost about 2.5 degrees over the course of an hour. Before, it would have been more than 5 or 6 degrees, so some improvement in that regard. The second brew was the founder's stout clone, which with a larger grain bill, only lost about .5 degrees over the course of the hour long mash. :rockin: I am using a Thermapen, so I am confident in my temp readings at least. Its seems with the smaller grain bills I might have some messing around to do with to get that 2.5 degrees loss in temp down a bit further, but it's a start.

Whether this trend remains for future brews, at least at the moment it seems to make a difference! I appreciate everyone's input!

 

[Subdivisions]

How big is the cooler you're mashing in?? I've heard of people putting some foil over top of the mash to keep in the heat if there's excessive head space in the mash tun. That head space could account for the larger heat loss in the 2.5 gallon batches.

 

[j_dawg]

How big is the cooler you're mashing in?? I've heard of people putting some foil over top of the mash to keep in the heat if there's excessive head space in the mash tun. That head space could account for the larger heat loss in the 2.5 gallon batches.

I am using a 5 gallon cooler, it is all I have space for in my apartment! Wish I could do a 10 gallon one for the 5 gallon batches. I haven't heard of using aluminum foil, I might have to try that for the next one. With the 2.5 gallon batches, there is definitely quite a bit of head space, so you might be on the right track on that one as to why the 2.5 gallon batches have more heat loss. Thanks!