Consequences of a wavering mash temp?

[Javaslinger]

So I'm doing about 2gal BIAB and my pot is not quite holding temp despite elaborate koozy constructions.

First batch was a stout and the temp cycled around 162 down to 146 as I attempted to regulate via the burner. I think the recipe indicated a medium body 154 was the intention. Obviously it spend time in both the simple sugar range and the complex non-fermentable sugar range. Efficiency was decent at about 80% and OG was pretty high - but this was for a number of reasons outside of the mash temp.

2nd batch, an IPA, was more well regulated via burner cycling about 152-156... In this case it was a full body mash profile so I was supposed to keep it up at 156.

Now I'm sure both batches will be fine in the end, but what will be the perceived differences by not keeping my mash precisely where it was intended to be.

Thanks!

 

[cubalz]

The main things you will notice is that a) the body of your beer will not match the style profile. Getting the correct body and mouth feel of the grain bill is wholly dependent of hitting the correct mash temps b) you will not hit your desired numbers according to the recipe (Beersmith etc)

 

[kh54s10]

The first is more problematic. I don't think you will notice much difference in the second one. Not perfect but close enough.

For that small batch I would preheat the oven to 150 degrees,turn the heat off, get your mash temperature then put the pot in the oven. You will probably get a drop in temperature, but only a degree or two. Just put the pot in the oven and walk away for an hour.

 

[violinguy]

You will also fine that your mash is at different temps depending on where you probe it. I do 3 gallon BIAB batches and I turn off the burner, put the lid on, and wrap the whole thing in an old winter ski coat (that I definitely don't use anymore in ATL). I've never had a loss in temp of more than 2 or 3 degrees. Everyone's results will vary of course.

I stir twice, and each time, the temp goes up anywhere from 2-6 degrees. I've also started using one of those thermometers with the long chord so I can keep an eye on the temp without taking off the lid.

 

[Weezy]

If you're at the point in your brewing experience where you're worrying about this fine if a detail, you might consider recirculation and temp controlled heater arrangements.

There are a lot of complications that come with brewing small batches, and this is one of them. I don't think a lot of 5+ gallon brewers recognize that.

 

[NSMikeD]

at 2 gallons, the warm oven should do the trick.

If your oven only goes down to 170, turn it off after 20 minutes

 

[kh54s10]

If you're at the point in your brewing experience where you're worrying about this fine if a detail, you might consider recirculation and temp controlled heater arrangements.

There are a lot of complications that come with brewing small batches, and this is one of them. I don't think a lot of 5+ gallon brewers recognize that.

I brew mostly 5 gallon batches but use the oven for smaller batches. I don't really worry about temperature loss during the mash. I get the right temperature at the start, use the heated oven to keep the ambient air temp close to the mash temp. I think I only measured the loss on the first batch I did that way. It was only a couple of degrees.

Most say that 90% of the conversion is done in the first 20 minutes. So a few degrees in 60 minutes is not a big concern.

With my cooler mash tun for 5 gallon batches, I just insulate it as well as I can, close it up for the hour and wait....

 

[Javaslinger]

Thanks everyone. I understand why I'm losing temp and various methods to combat it. However, I'm really interested in understanding what will be the impact of 1) heating the mash throughout and 2) What impact will it have spending time basically throughout the extent of mash temps rather than dialed in. Will one supersede the other?

 

[VagueSkunk]

According to a recent 'exbeeriment' on brulosophy.com....not much difference will (probably) be noticed and both beers should be just fine.

 

[Weezy]

Most say that 90% of the conversion is done in the first 20 minutes. So a few degrees in 60 minutes is not a big concern.

This depends on the crush. Mashing is about getting the starches out of the grain and available to the enzymes for conversion. Actual conversion is momentary.

 

[kh54s10]

This depends on the crush. Mashing is about getting the starches out of the grain and available to the enzymes for conversion. Actual conversion is momentary.

Actual conversion may be momentary, but to get a crush that would allow that would be a huge problem for brewing. It would be so fine that all the grain would end up in the fermenter without very specialized brew techniques and possibly equipment.

 

[Weezy]

Actual conversion may be momentary, but to get a crush that would allow that would be a huge problem for brewing. It would be so fine that all the grain would end up in the fermenter without very specialized brew techniques and possibly equipment.

You're not understanding what I said. If you put in whole grain, ir might take umteen hours to get the starches out of the grain. But once the starches are in solution, the enzymes will covert them in moments.

I do a Brutus 20 mash-sparge technique with a vey fine crush and a biab bag. By the time I've mashed in, waited 10 minutes, checked pH, made any adjustments for pH, it's been 15 minutes and I start recirculation with sparge water.

 

[kh54s10]

You're not understanding what I said. If you put in whole grain, ir might take umteen hours to get the starches out of the grain. But once the starches are in solution, the enzymes will covert them in moments.

I do a Brutus 20 mash-sparge technique with a vey fine crush and a biab bag. By the time I've mashed in, waited 10 minutes, checked pH, made any adjustments for pH, it's been 15 minutes and I start recirculation with sparge water.

Well there you go.. 10 minutes is not momentary and a very fine crush is not the norm. So in general it takes a little time.. How much is partially determined by how long it takes the wort to fully saturate the grains. It is generally accepted that by 20 minutes the average grainbill is mostly converted. It obviously doesn't happen instantaneously otherwise people would be mashing for 5 minutes rather that 60.

 

[Weezy]

Whatever you say bub. I give up.

 

[NSMikeD]

Thanks everyone. I understand why I'm losing temp and various methods to combat it. However, I'm really interested in understanding what will be the impact of 1) heating the mash throughout and 2) What impact will it have spending time basically throughout the extent of mash temps rather than dialed in. Will one supersede the other?

On thing about heating mash is that I found near the bottom temps can be as high as 180° even though the middle of the pot is reading 150° even with the burner on low. You really have to watch it and stir like crazy. Probably explains my earlier inefficiencies with lower OG (and thus sweater beer) since temp that high destroy the enzymes.