Temp Control... First Partial Mash

I've been an extract/specialty grain brewer to this point.

I really want to do an Oatmeal Stout, so I suppose I'll need to do a partial mash to convert the oatmeal. I've ordered a kit from Northern Brewer.

I'm concerned about temp control. I read the BYO article on Countertop Partial Mashing, but the numbers don't seem to add up between the NB kit and the technique that's outlined. And I don't know how to convert everything to make it work.

The inventory calls for 153 degrees for 60 minutes and 170 degrees for 10 minutes.

How can I reach and maintain this temperature with a minimal equipment investment?

Thanks for any help you can offer!

Easy as pie!

I did a lot of stovetop PM's before I got into all grain...and I still use the same technique now that I did back then...though I now use a propane burner and a bigger kettle.

I got my technique from Papazian. It's a direct-fired stepped mash technique. You mash in the kettle, and you regulate the mash temps by using the heating element (stove/range/burner/etc). First off, your initial temp rest will be achieved through a hot water infusion. In other words, you'll heat your water to a certain temp that is higher than your target temp, and dump it into the kettle with the grains. If you've calculated your temps correctly, after this hot water infusion is made, your mash temp should be roughly at your target.

So, my schedule looks like this: 133f for 30 mins, 149-155f for 45 mins, 158 for 20 mins or until an iodine starch test is negative, then mash out to 167. This always yields better mash efficiency for me than single-step infusion mashes.

So let's take a recent brew of mine as an example, a cappuccino stout. I started with 12.78 lbs of grain, and my mash water was 4 gallons. In order for my first rest to be at 133, I heated those 4 gallons up to 141f (this calculation is courtesy of ProMash brewing software), dumped it into the kettle with the grain, mixed it up, and took a temp reading. It was around 133f. I rest there for 30 minutes. Then I put the kettle on the burner and turn the heat on, stirring constantly to avoid pockets of heat that can denature the enzymes. I keep the heat on and keep stirring until I reach 149-155, then turn the heat off. I rest there for 45 minutes...and so on. Since you're using a non-insulated mash tun, there's bound to be some temp drop during the mash. If this happens, just apply a little bit of heat and stir until it gets back to your range.

Now, you'll also need something to drain/sparge with. Do you have a pasta strainer insert or something like that?

Thanks for the response!

I do have a large strainer that I believe will work well for this.

So, the NB directions say-
153° F for 60 minutes
170° F for 10 minutes
(full directions below)

So, you're basically saying, keep the brew kettle on the burner and heat as needed?

The directions included with the kit say to put the grains in there first. This would mean you wouldn't have to over heat the water to take into account the heat lost by mixing in the grains. Correct? Then again they say to wrap towels around it to maintain the heat.



Instructions
Activate your yeast bag at least one day before brewing. Northern Brewer suggests making a wort starter to increase yeast population before brewing.

On brewing day, measure one gallon of water into the mash kettle and another gallon into the sparge kettle.

Add the grains to the mash kettle.

Heat the mash kettle to the first temperature rest, as indicated in the “mash schedule” of the kit inventory sheet. Stir gently throughout to maintain consistent temperatures within the pot. Not all kits will have the same mash schedule; some recipes will include a protein rest at 122° F for 30 minutes before the saccarification rest at 150° F. As the water approaches the target temperature reduce the heat and gently stir the water. Remember that most thermometers don't read instantaneously. Don't overshoot your target temperature.

Remove from heat and maintain your target temperature for the amount of time specified on the mash schedule. There are several options to help with this task:

Place pot in a cardboard box and surround with towels to insulate.

Place in a WARM (but not heating) oven.

Periodically check the temperature. You may find it necessary to return the mash to the burner to raise the temperature, but proceed slowly and stir continuously to avoid over heating the mash. A few degrees too low is not critical.

During the final 15 minutes of the saccharification rest (this is the rest at 150° F), heat the water in the sparge kettle to 170° F. This water will be used to rinse sugars from the grains after the mash. This is called the sparge water.

Once mashing is complete, pour the entire contents of the mash kettle through a strainer into the boiling kettle. (If you don’t have another pot, you may use your bottling bucket or any container to hold the wort until you can clean the mash kettle, which you will use for boiling.) Gently pour the sparge water through the grain in the colander/strainer and into your brew pot. Your goal is to extract sugars and leave as much husk behind. Some husk material will inevitably slip through in a partial mash, but try to keep this to a minimum.

Once the mash and sparge wort is collected, add additional water if your pot allows. Dissolve your malt extract and boil, adding hops according to the recipe and proceeding as you would for an extract batch.

Well, you don't HAVE to do the intermediate rest at 133f like I do...I'm just telling you that I always get better efficiency from it.

The 170f rest that they're talking about is the sparge. You don't wanna heat your mash to 170 for that long. But do it like I said if you want. I personally like the process. I've never done it in the oven, but I suppose it'd work. The only problem I see is that you can't keep a thermometer in there with it.

Yeah, you could definitely heat the mash directly for your first step if you wanted to. I just find that I can hit my temps much more accurately by doing an infusion---because the thermometer is much more accurate in water than it is in the mash. The mash has pockets of cool and hot, so you have to continually stir it to make sure it's uniform and your reading isn't taken from one of those pockets. The 10 or so degrees over what your target is won't take long to reach either. But if you don't have brewing software, then I guess it'd be easier NB's way. Or you could just ask someone here...like me. I could plug your grain weight and water volume into ProMash and give you an infusion target temp if you want.

As for the towels...never done that. I guess it'd work, but only if you use the oven trick.

So, just to re-iterate the process- you heat it up above the target temp, put in the grain and turn off the heat. Then you periodically check the temperature and re-apply heat as needed. Does that sum it up?

I can get Pro Mash if it's going to make my life easier. It seems that what most people use.

Thanks again!

Here's the full inventory if you want to plug it in and let me know what it comes back with-

Fermentables
3.15 lbs. Gold Malt Syrup
1 lbs. Golden Light Dry Malt Extract
1.5 lbs. Crisp Maris Otter
1 lbs. Flaked Oats
0.5 lbs. Simpson's Roasted Barley
0.5 lbs. Simpson's Chocolate Malt
0.5 lbs. Simpsons Dark Crystal

Boil Additions
1 oz. Chinook (60 min)

Yeast
Wyeast #1084 Irish Ale Yeast. Slight residual diacetyl and fruitiness; great for stouts. Clean, smooth, soft and full-bodied. Flocculation: medium. Apparent attenuation: 71-75%. Optimum temperature: 62-72.

nicholschris said:

So, just to re-iterate the process- you heat it up above the target temp, put in the grain and turn off the heat. Then you periodically check the temperature and re-apply heat as needed. Does that sum it up?

Click to expand...

You heat up the water above the target temp (but you need to calculate how far above), dump it into the kettle with the grain, stir, and leave it on the burner, covered, with the burner off. Apply heat to the mash kettle as needed.

I can get Pro Mash if it's going to make my life easier. It seems that what most people use.

Click to expand...

I bought it because someone recommended it. I like it. The GUI is primitive, but it still does everything I need it to do and more. I'm a fan. But some people use beertoolspro or beersmith.

Thanks again!

Here's the full inventory if you want to plug it in and let me know what it comes back with-

Fermentables
3.15 lbs. Gold Malt Syrup
1 lbs. Golden Light Dry Malt Extract
1.5 lbs. Crisp Maris Otter
1 lbs. Flaked Oats
0.5 lbs. Simpson's Roasted Barley
0.5 lbs. Simpson's Chocolate Malt
0.5 lbs. Simpsons Dark Crystal

Boil Additions
1 oz. Chinook (60 min)

Yeast
Wyeast #1084 Irish Ale Yeast. Slight residual diacetyl and fruitiness; great for stouts. Clean, smooth, soft and full-bodied. Flocculation: medium. Apparent attenuation: 71-75%. Optimum temperature: 62-72.

Click to expand...

Anytime! I recommend using 1.25qts per pound of grain, which means you'll mash with 1.25 gallons of water (not counting the sparge water).

Assuming your grain is room temp, 75f, and you haven't preheated your mash kettle, your initial strike temp for the mash water should be 142f.

Then sparge with at least 2 gallons of water.

Good luck!! Anymore questions, let us know.