Mashing Programs: Tips from the Pros

 Jay Misson
Mountain Valley Brewery

We do single step mash. Soon we’ll have a system that is capable of decoction and temperature program (also known as step or upward infussion) mashing. At times I will use that decoction capability. The type of mash I do will really depend on the brew style and the malt. For the most part I’m using malts that don’t require decoction.

When doing a single step mash, brewers should try to get their hands on sour malts. Sour malts have a lot of lactobacillus delbrrueckii bacteria that will lower the pH of your water. If you can get the pH down to 5.2 to 5.4 that’ll bring out a lot of the malt’s character that you might not otherwise achieve.

Sour malt helps the enzymes in breaking down the starches, it will help the break during the boil, and it will help the fermentation.

It does depend somewhat on the pH of the water that you’re beginning with. If you have really soft water with a low pH to begin with, it may not be necessary. Where I brew, we have fairly hard water. The sour malts bring it down in that range–5.2 to 5.4.

The only trick to using sour malts is that you might have to mill it a little finer than regular malts because it tends to be soft.

You can use the sour malt with any mash technique but not with any beer style. I like to use it with the lighter styles, like a pilsner or paler ale. Usually you have a lower pH with dark malts as it is because the roasting process lowers the malts’ pHh.

For homebrewers who are just starting with a full grain approach, a single-step infusion would be the obvious starting point. Once they decide how they like that they can go further into the more complicated mash styles.

The homebrewers’ goal should just be to be happy with what they are doing.

Geoffrey Larson
Alaskan Brewing

We do an upward infusion mash. We chose this style because it gave us the most flexibility. We can get the most out of our malt and, at the same time, create a really malty beer without a clowy, sweet aftertaste. We brew a variety of styles ranging from alt to porter using upward infustion mashing and ale yeast.

Upward infusion is good for any style of beer. I think it can be a little more difficult and tedious [than other mash styles] but I think the effort that’s involved is definitely rewarded in the end.

Comparing upward infusion mashing to other mash styles, a single step infusion is simpler—you don’t have to sit there and raise the temperatures. As far as difficulty goes, if you can do decoction mashing, you can do upward infusion.

One of the most important things about upward infusion mashing is to be careful about scorching. It is really easy to burn the bottom of the mash. To avoid scorching, stir the mash regularly or try to get indirect heat through diffusers.

When you start heating the mash, make sure the grain is very well wetted and well stirred. If you have any dry grains they will go down to the bottom and then it can burn almost instantly. If you’re going to start at a low temperature and raise it up, don’t put the pot on the heat right away—don’t have the water on the heat when you add the grains.

Although recipes will call for specific amounts of water, as a rule of thumb, try to maintain not too much more than three pounds of grain per gallon of water.

Raise your temperature about a degree a minute. That helps maintain a slow enough heat transfer so you don’t scorch the wort.

It’s easier to scorch the wort at lower temperatures than at higher temperatures because you don’t have as much liquid in the grain/water mix. As you go up in temperature, the mix becomes less stiff; therefore, it’s less likely to sit on the bottom of the pot.

Raise the heat as high 171° F. You don’t want to go over 172° F because you’ll get tannins coming into the wort. The tannins can give a really dry, tea-like character in the beer.

The higher the temperature up to 171° F, the easier it is to get a better run off. Once you go through your temperature rises and it hits 171° F, go ahead and lauter.

Count the degree a minute right when you start heating, but you can start with fairly warm water. The most critical temperatures would be the infusion temperatures. Those are a range of temperatures between 150° and 154° F. The lower temperatures, as low as 90° F, are mainly protein rests.

There are a number of different protein rests in the 95° to 130° range. Protein rests help in clarity and, particularly with wheat beers, the rests help with run off. Protein rests are probably more important to some of the larger breweries because they are overly concerned sometimes about hazes. Homebrewers are more concerned with how the mash process effects their malt flavor.

When you are talking about a degree a minute, many brewers will have specific temperature rest points. I think you will find that a degree a minute gives you a lot of latitude to cover those specific points.

Upward infusion is definitely something homebrewers can play around with, but if you’re just starting all-grain you have a lot on your plate. I would start off with a single temperature mash.

In any mash technique be well aware of your water quality. Even though sometimes some breweries over emphasize the importance of their water, there is a lot that goes on in the mashing that depends upon some of those calcium ions and the like in the water. Make sure you use your brewing salts as would be recommended by the specific recipe. It makes a big difference in mashing.

David Grinnell
Boston Beer Company

We are currently making 14 different beers here and we have different mash techniques for different beers. For our flagship brand, Boston Lager, we use a decoction mash.

Part of the reason we use a particular mash for a particular beer is tradition. Part of it is equipment related. In the case of the Boston Lager, we had a historical recipe that we wanted to do our best to faithfully interpret so it required that kind of mashing program.

The type of mash you choose really depends on what your objectives are. If we are going to do a decoction mash it’s going to mean we want certain things in the finished beer. We believe that there is a flavor impact from taking part of the mash to the cooker and boiling it that is a kind of handling that the main mash does not see. Those temperatures. Also if you are going to drop a boiling mash from a cooker into the mash mixer you’re going to get a very rapid gain in the temperature when those two mashes are blended. That’s going to result in a certain kind of final beer. What it’s going to do its give you a high final attenuation. It’s going to really put body in your beer. That’s one of the techniques to making the beer kind of chewy. Boston Lager is a beer that requires a pretty decent final gravity in order to carry all the flavor we put in the beer.

Our choice of mashing technique is built around what we want to acheive. If we were going to make a traditional kind of ale with a single temperature infusion mash then there’d be no need to go with decoction. You would just mash in at your conversion temperature and rest for some suitable period of time. You get your malt wet at 149° or 150° F or something and then read the paper and have a dozen donuts and come back and run it off.

If you were going to do a decoction mash on your stove you would need to have some kind of confidence about what temperature you were at in both mashes. You need to know you are at a boil or at some specific temperature in your cooker mash. Then you are going to drop that into another mash and you should know pretty precisely what that temperature is. When you blend those two mashes you are going to get a third temperature. In order to get repeatablity–the ability to make that brew week after week–you have to have confidence in your temperatures.

Also when you are dropping the cooker mash you have to have good agitation, good mixing into the main mash. When you drop the cooker in there you don’t want pockets of very hot mash.

It sounds like a two-person job. One person holds whatever vessel you use as the cooker, and slowly adding it to the main mash while the other person stirs the main mash to make sure there is even distribution. You don’t just bomb it in.

In the brew house you are really laying the ground work for the base beer. Really laying in all the important numbers relative to fermentability. Depending on how fast you go through the conversion temperature and how much time you spend there you’re going to determine what your final degree of fermentability is going to be. How much alcohol your beer’s going to have and all of that. Those are variables that you can manipulate to make different beer styles. If you want a really chewy beer with a lot of mouth feel then you would want to execute that cooker drop very quickly. In which case put some face shields on and drop it in real quick. Stir it real quick and don’t spend much time at all in conversion.

The other thing you need to do if you’re going to do a very agressive drop like that is once the cooker is empty, check for conversion. Do your iodine test. If you have conversion, proceed to your mash off temperature, which in most cases is 168° to 170° or something in that range.

If you go back 100 years, (doing the decoction at a fast pace) is what all brewers had to do. The thing that has happened in the past 100-plus years is a lot of breeding on the malt side. Now we have malts that have good enzyme levels that are easily converted and are highly modified coming right from the maltster. It used to be that you had to cook the hell out of this stuff to get some results. You would have triple decoctions. Taking material out of the main mash not once but twice and boiling it and returning it to achieve different temperature levels.

From my perspecive, we enjoy being production brewers. We enjoy being consistant with our final product. We find that even though we do the same thing the same way day after day in order to give our customers the same familiar taste in each of our brands, there are enough variables in brewing to keep things exciting. There are issues on the sanitation side, two of your main ingredients are agricultural so there’s some variability there. In terms of mashing we just try to be as consistent as possible. If you are interested in making If you come across a batch of your beer that you consider to be perfect or right on, I would get as much information as to how you did that as possible. How did you do it? even if you stirred with your right hand rather than your left hand. It depends on how rustic your homebrew set up is, if you want to have repeatablitily with your system you have to take good notes. If you go to a production brewery, then you ran the agitator for five minutes at medium speed. The details are important.

Have a couple of good thermometers you trust. Have a way of stirring your mash that is effective–that can really get the whole mash up and mixed well with the cooker mash. Be careful. You are boiling a liquid here and you can have some burn problems. But it’s not something that anyone should be shy about.

Issue: November 1995