Mash Thickness and Step Infusions

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.

momobono

Well-Known Member
Joined
Dec 4, 2011
Messages
56
Reaction score
1
Location
Somerville
I'm a beginner AG brewer, but I have a few batches under my belt. I'm also a proponent of tweaking my recipes to make them my own, which means I'm also brewing different styles all the time. Changing mash thickness per style is advice I've gleaned from books and forum posts here, but there's no reference to the "idea" of mash thickness in an operational capacity.

For example, I'm planning a wit recipe and aiming for a mash thickness of around 1.5 qt/lb. My mash schedule includes a 111F ferulic acid rest, a 154 saccharification rest, a mash out, and a batch sparge. All of these steps, on my igloo-cooler and turkey-burner system, require me to add boiling mash water.

The question: where in the mash process do I target my final thickness? On my lowest rest, or in my mash out? Maybe on my saccharification rest, since that will be my longest rest (60min)? I've brewed a few batches where my ending mash thickness (after mash out) has been 2.0 qt/lb or higher, and I'm unsure if that's making it more difficult for me to hit my gravity numbers (I'm usually below my target post-boil OG).

Any help would be appreciated, I already have learned toooo much from the experience that's documented here.
 
A quick followup: I asked a pro brewer (Battle Road Brewing Co.) this question. He recommended that if you're using boiling water to increase the temperature in your mash, the target mash thickness should be hit around the saccharificaiton temperature rest in order to best manage your sugar extraction. Just FYI.
 
When I saw the ferulic thing, I figured some kind of wheat beer was in the works. A thicker mash, early in the mash process, at a certain pH and temp, increases enzymatic effectiveness. Which helps with conversion later on. A thin mash at sacc. temp of 149/150 favors maltose production. You're hung up on the target mash thickness and boiling water thing. I hate Charlie Crapasians RDWHAHB acronym. But, in this case it fits. So, RDWHAHB. Here's the thing. Using the step mash method. A certain volume of boiling water is needed to hit a certain rest temp, in a certain grain bill. The volume can vary, because, of initial grain temp, tun temp and how much heat the tun will lose during the rest. So, if the 1st rest is at 111F, it will take a certain volume of water to hit the temp. The certain volume of water infused, is going to create a certain mash thickness. Same thing with the sacc. rest of 154F. So, how can mash thickness be regulated, when it takes a certain volume of boiling water to hit the rest temps? It can't. If you adjust the volume of boiling water infusion, you change the rest temp and mash thickness. Get my drift? So, to answer. "The question: where in the mash process do I target my final thickness?" You are going to get a mash thickness, based on the volume it takes to hit the rest temps. The mash is going to be thicker at the 111F rest, than later, when you dump in enough water to go from 111 to 154 and thinner, when you mash out. You pickin up, what I'm throwin down? Since, you are doing an acid rest of some kind. The mash pH will be in the park, a decoction can be pulled, and boiled without stripping tannins. (Do you have a pH meter and a good thermometer?) Instead of infusing water, use a decoction to go from the acid rest of 111F to the sacc. rest of 154F. Then, if you need to add boiling water infusions for temp maintenance, a lot of water won't be needed. Same thing with mashing out. After conversion, pull the mash liquid and boil it and add it to the tun for the 168-170F mash out temp. You may need a small volume of boiling water to hit the temp. Wit beers were originally double decoctioned. Why mash out? The batching method doesn't necessarily need one. Mash out is used to denature enzymes and to heat up the mash to allow extract (sugar) to flow through the grain bed filter during sparging. Like the pro. brewer said, "to manages sugar extraction." Got that? He didn't say to manage conversion. Use the boiling water that you are using for mash out as a big part of the sparge water. If 2qts. or more per pound of boiling water is needed to hit the temps, the recipe calls out. But, you aren't getting the yield, the recipe says you should. Either, the recipe is haywire, or the brewing process is. On the other hand, since you like to tweak stuff. If you created the recipe, you may need to de-tweak it or reformulate. The 1.5 qt/pound thing was written as a base volume for infusion mashing. A one temp rest, with no consideration of mash out. It is used to create a standard mash thickness, that can easily be run off, through a slotted or perforated plate. The volume isn't written in stone, for every beer brewed. Keep at it. It takes time.
 
Not sure why you're doing a ferulic acid rest for a witbier.

The generally acceptable range is from 1 to 3 qt/lb. You will just get slightly higher fermentability at higher dilution rate.

Thicker mash is beneficial for a protein rest as it protects the proteolytic enzymes better.

From Kai Troester:
"The temperature steps necessary for this mash schedule can be achieved through infusions of boiling water or direct heat. If boiling water will be used the mash should be doughed in with a water to grist ratio of about 2.5 – 3 l/kg (1.25 – 1.5 qt/lb). Don’t be afraid of thinning out the mash through the hot water infusions. It will become easier to handle and enzymes and gelatinization also work better in a thinner mash."

http://braukaiser.com/wiki/index.php?title=Infusion_Mashing
 
Not sure why you're doing a ferulic acid rest for a witbier.

Since I want that clove-y, 4-vinyl guaiacol coming off of my belgian wit yeast, feruilc acid rest is a must.

@Vladoftrub, I brewed this yesterday, targeting my mash thickness at 1.33 during the saccharification rest. If I had the time, experience, and resources (read: pH meter) to double-decoct this brew it would certainly be a better option. I may have misquoted my pro brewer friend - it was indeed the sugar conversion that he was referring to, and I figured in the mash-out to hit my pre-sparge volume collection. Looking back at my notes, my efficiencies really stay around 60-65% over the last few brew days, so the RDWHAHB mantra re:mash thickness may be in play as it's not as important as having the correct amount of grain to hit my numbers on my system. As I get more dialed in I can worry more about that stuff. But it's an interesting question to think about, no?
 
The OP mentioned he likes to tweak things. That's not a bad way to learn.
Ferulic acid can't be produced until the mash pH is around 5.6-5.8. He is focused on the ferulic thing, kind of like being focused on mash thickness in an operational capacity. The pH range, not only produces the ferulic stuff. It sets the alpha amylase in gear, to break down complex starches. As the mash pH drops during the rest, beta amylaze kicks in gear, working on the starch that the alpha amylase broke down. I drank Hoegaarden Wit and didn't taste of bananas nor cloves. It was a little sweet, light yellow haze and white head. Smelled and tasted of oranges and a little spice. I'm not big on wheat beer, but that wasn't too bad. It bangs ya up pretty quick, it goes down real good.
 
4-VG is more dependent on the type of yeast you use. To my taste wit yeast makes other "rubbery" phenols.

Wheat beer brewers worry more about doing a protein rest.
 
A couple ideas to keep mash thickness constant:
You could mash in your kettle. Mash in at your target thickness at 111, then turn the burner on low and stir constantly while bringing it up to your sachrification rest.

Do a decoction. Its actually not that hard.

Try your recipe without the 111 rest and see if you even need it. Might be fine without it. Also, since you like to tweak, it would give you a baseline to compare against when you try the same recipe with a rest. Keep it simple first, then get complicated.

Cheers!
 
As far as I know, the ferulic acid rest is most useful for WEIZEN yeast, not witbier yeast. In my experience, wit doesn't have that much clove, though strains vary, obviously.

But yes, I agree that the mash thickness to target is for your main 154F rest. And I also agree that decoctions are an important tool to have in mind when you need to hit multiple temperatures but can't heat the mash tun. With more than 2 rests, it can be hard to hit each one with boiling water to the right precision. A quick decoction can help raise things a few degrees if you need to.
 

Latest posts

Back
Top