A Few Questions Regarding Partial Mash...

So I'm making the step-up to partial mash, and have a few questions. I've read tutorials, and the best one had a guy draping a large nylon bag over his pot. So the grain was basically floating in the pot, but when he pulled the bag out, the grains came out with it.

My LHBS and the places I generally order from do not have bags large enough to fit over the entire opening of my pot. So I'm wondering, for a partial mash, do the grains need to be "loose" floating in the water, or can I divide the grain between a few steeping bags? Looking at it another way, can the grains be added directly to the pot, and strained out after the mash and sparge with a standard metal strainer...or is this asking for a mess?

Regarding water volume: I understand the amount of water one has dictates how much grain can be used. I recall reading about a ratio of 1.2 quarts of water for every pound of grain. Is that ratio for all grains, or just for the "base" grains. To give an example, lets say I had a 1.2 quart mash volume (I'd never go that low, but to keep it simple). Would my grains have to be 1.2 total or could I have 1.2 of 2-row and an additional compliment of specialty grains?

Does the sparge volume have to equal your mash volume? The primer I read used 2 gallons mash volume and 2 gallons sparge volume for a combined 4 gallon boil. 3 gallons in the boil is about the max I want to deal with at this point, just because I have to carry the heavy pot down a flight of stairs, etc etc, and don't want to drop it. In an effort to get the most I can out of that 3 gallon boil, could I maybe use a 2 gallon mash volume and a 1 gallon sparge volume, or is this asking for problems?

Finally, about how much grain do I need to use in order to get proper hop utilization? I prefer to add as much of the extract at the end as possible, and with a partial mash I'd like to get to the point where all of it is being added at the end, if possible.

Thanks very much for your time.

So I'm making the step-up to partial mash, and have a few questions. I've read tutorials, and the best one had a guy draping a large nylon bag over his pot. So the grain was basically floating in the pot, but when he pulled the bag out, the grains came out with it.

My LHBS and the places I generally order from do not have bags large enough to fit over the entire opening of my pot. So I'm wondering, for a partial mash, do the grains need to be "loose" floating in the water, or can I divide the grain between a few steeping bags? Looking at it another way, can the grains be added directly to the pot, and strained out after the mash and sparge with a standard metal strainer...or is this asking for a mess?

There are various methods you can use, incliding strainers or making your own bag or leaving it loose in the water. Most AG brewers do this and fit a manifold to the mash tun.

Regarding water volume: I understand the amount of water one has dictates how much grain can be used. I recall reading about a ratio of 1.2 quarts of water for every pound of grain. Is that ratio for all grains, or just for the "base" grains. To give an example, lets say I had a 1.2 quart mash volume (I'd never go that low, but to keep it simple). Would my grains have to be 1.2 total or could I have 1.2 of 2-row and an additional compliment of specialty grains?
Does the sparge volume have to equal your mash volume? The primer I read used 2 gallons mash volume and 2 gallons sparge volume for a combined 4 gallon boil. 3 gallons in the boil is about the max I want to deal with at this point, just because I have to carry the heavy pot down a flight of stairs, etc etc, and don't want to drop it. In an effort to get the most I can out of that 3 gallon boil, could I maybe use a 2 gallon mash volume and a 1 gallon sparge volume, or is this asking for problems?

I'd say the mash ratio is more important than matching the sparge volume.
The amount of sparge water is limited by 2 factors.

• The size of the boil you can do.
• Not letting the gravity of the drained wort going below 1010

Finally, about how much grain do I need to use in order to get proper hop utilization? I prefer to add as much of the extract at the end as possible, and with a partial mash I'd like to get to the point where all of it is being added at the end, if possible.

I'll leave that for the experienced PMers to answer.

Thanks very much for your time.

Go to Home Depot and pick up a 2 pack of "Nylon Paint Strainer Bags". They are 5 gallon size bags with a stretchy top like a shower cap that fit over your pot. They will be close to the paint mixing counter. For 2 of these, you pay the same you would for 1 that a homebrew shop would sell you (about $5.00)

And yes, it helps if the grain is loose so you can stir it up and get rid of any dough balls.

/I said balls.

I'll chime in here and say that DeathBrewer's tutorial is about the best one that I've seen regarding PM. The paint strainer bags from your local big box store are indispensable as a separation medium when doing countertop partial mashing. The best thing about that particular setup is that it doesn't require any addition equipment save the paint strainer bag.

The mash thickness and temperature will influence the fermentability of the wort and the efficiency of enzyme conversion. Too thin of a mash, and the enzymes have trouble getting to and converting all the available starches. Too thick, and you have the same problem.

The amount of grain in the mash will dictate the amount of liquor used in both the mash infusion and the subsequent sparging. I typically use a water:grain ratio of 1.25 qts:1 lb of grain, and sparge to get to my preboil volume. Grain will absorb .10-.12 gallons per pound, in my experience. So let's go through the math with a 5 lb grain bill:

- Infusing 1.25 qts/lb gives us a mash liquor volume of 1.562 gallons. For simplicity's sake, I'll round down to 1.5 gallons. Mash at the temperature dictated by the recipe- say, 152, for 45 minutes- 1 hour to allow for full conversion.
- Given the absorption factor of .10 gallons/lb, I'm going to see first runnings of approximately 1 gallon.
-To achieve my 3 gallon preboil volume, I'm going to sparge with 2 gallons. The grain isn't going to absorb any more water, so it's just simple arithmetic from here on out.

noremorse1 said:

/I said balls.

Click to expand...

Heh. I'll be going to the De Pot soon, so I'll pick up a few of those bags.

I have obsessed over partial mashing and there are so many good ways to do it I really do not think one is better then the next. Some people do it one way and others another way and all turn out great.

for instance - one expert will say pour 170 degree water gently over the grains at the end while another well known expert says to steep the grain bag in 2 gallons of 170 degree water for 10 minutes at the end.

This is the beauty of brewing. There are so many "right" way to do things it's hard to go wrong.

The key to brewing is understanding the WHY and not the HOW - there are many HOW's.

BTW - I go with 1.5quarts of water per pound. As for your problem. I think you can use a number of bags but the key is to make sure the grains are floating free and not bunched together. They need to be able to have water floating and mixing.

Regarding hop utilization, I partial mash using converted AG recipes shooting for a 4-5 lb grain mash with the rest as extract. I can boil 3 gallons, so typically I'll add about a small amount (a cup or so) of the extract to the mash runnings and start my boil, adding hops per the original recipe. This seems to get me pretty close to the IBUs I'm looking for and I've yet to be disappointed. The rest of my extract goes in with 10 minutes left where it doesn't really affect the late aroma hop additions.

If your partial mash is smaller than 4 lbs, you'll probably want to increase the early extract addition proportionally. I tend to shoot for about 1/3 of the total fermentables for my partial boil when I'm using a hop schedule geared toward a full boil AG recipe.

Water volume - I do the mash using a 1.25 qt per pound of grain (plus a little to make up for the grain soaking), then sparge with whatever volume is I need to reach my boil volume. For instance, 3 gallons is 12 quarts so with 5 lbs of grains I'd mash with 6.5 quarts of water, then sparge with another 6.5 quarts (the grain will soak up close to a quart). For a 4 lb mash it would be 5.25 quarts for mash, 7.5 or so for the sparge.