can someone explain this..

so far I've done a handful of partial mashes from austin homebrew. in their instructions, it says bring 2.5 gallons of water to mash temp, 155-160. then soak base/specialty grains in there for ~45 min.
then to sparge, use 1 qt. per 2lb. grain to rinse.. then on with boil.


now on brewwiki, they define single infusion mash and temperature mash.

On single infusion mash, it says this is the step that you use 1.25 qt. water per pound of grain, when actually mashing in a container of sorts.

it seems so far I've done temp mash, because i always just use about 2.5-3 gal of water regardless of grain bill, and i keep it in the pot, although i may soon make a mash tun.
temp mash says "Rather than adding a known quantity of hot water, the mixed water and grains are simply raised to the target mashing temperature and held at that temperature until the starch conversion is complete."



so can someone clear some of this up.. i'm a bit confused. when and why do you use 1.25 qt. water per lb. grain, and where/when do you top off to get 6 or 7 gallons to begin boil?

that temp mash and infusion mash seem the same to me, except that infusion mash has a known amount of water.

I don't know what a "temp mash" is...you may be mistaken on that term.

There is a "step mash", which means you start at a lower temp, rest, and then bring the temp to another temperature, rest, etc. Step mashes can involve acid rests, protein rests, saccharification rests, etc.

The "single infusion mash" just means you don't have a lower temp and you let it rest at your saccharification rest until conversion is complete.

"Infusion" simply means you are adding water to reach your temps. Another option is "decoction" which means you remove a portion of the grist, boil it, and then return it to the mash tun.

http://brewwiki.com/index.php/Mashing

this is where temperature mash is defined.


outside of that term, why would AHS have instructions that say put 2.5 gal. of water in the pot, regardless of how much grain i have?

Ahh, I see. So you just add them together and then apply direct heat? That's odd...I've used direct heat for step and mash out, but they just mix cold water with the grains and raise the heat? weird.

As for AHS having instructions with a set amount, it may be because all of their kits will work that way? I have a set volume (2 gallons) for my partial mash thread, that allows for 5-6 lbs of grain and will fall in the right range and temperature.

I generally use 1.25-1.5 quarts per pound of grain and use this calculator to mash in:

http://www.rackers.org/calcs.shtml

In the description of the temperature mash, it explains that this procedure is sometimes used commercially, but rarely by homebrewers. I've done it on the stove when I mashed in a SS pot, and didn't find it too difficult; and when I did it, I always knew how much water I had added.

As for mashing, You need to use between 1 and 2 qt water per lb grain. If you use much less water than that, you will not wet the grain sufficiently and could have difficulty converting. If you use much more water, you will dilute the mash to such an extent that the pH could rise above acceptable levels, again giving poor conversion. Within those limits, the buffering capacity of the grain should keep the pH in bounds.
After the mash is complete, you need to sparge (rinse) to get what you want out of the grains, and to discard the spent grains. You can then add as much top off water as you need.

-a.

I haven't used any of the AHS kits, but usually the homebrew shops have one set of instructions they try to apply to all of their kits. This means you basically shouldn't follow the instructions verbatim unless you are a complete beginner with no other resources for info.

ajf just covered the water to grist ratio for mashing, so I'll clear something up about that wiki. If you're not using a variable temperature mash schedule (i.e. step mash, decoction) then its single infusion. Regardless of what vessel you're mashing in, or how you achieve your temperature. What you describe as your process is a single infusion mash and batch sparge.

Your last question about topping off is an 'it depends' situation. Personally I'm more concerned with what gravity I'm at before boil. Knowing what your evaporation rate is (rough estimate is fine) will lead you to the proper pre-boil volume. Don't worry about having exactly X gallons of wort at the end of the boil, so long as the gravity is what you were shooting for. Topping up a beer blindly to hit a certain volume can ruin a beer.

well this makes me wonder about the AHS instruction sheet. the brew i did only had 1.25 lb Base Grains and 1.5 lb Specialty Grains, yeh the sheet said start with 2.5 gallons of water.

that is way too much according to this standard 1-2 qt. per lb.

I've done many AHS kits according to their instructions and had good success. Not gold medal beer, but good enough that it disappears in a hurry. Lately, I have mashed @ 1.33 gal/lb in a separate pot. But that is still in the secondary so the jury is still out.

I think the reason they instruct that way is because many may be brewing using a single large pot. The low grain bill in their mini-mash kits would call for only enough water to barely cover the bottom of the pot.

Forgot to add that in a partial mash brew you're not exactly worried about efficiency of the mash portion. So while 2.5 gallons might make your mash thinner or thicker than you'd normally prefer, its not a huge deal because you're making the rest of the OG up in extract. Now is a good time to experiment with strike volumes in a partial mash setting when there's less on the line. If/when you decide to go all grain you'll have some good experience to fall back on.