first partial-mash brew

Brewing processes and methods. How to brew using extract, partial or all-grain. Tips and tricks.

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MattieSy
Posts: 3
Joined: Thu Oct 06, 2005 1:36 pm

first partial-mash brew

Post by MattieSy »

Hey all. I'm trying to make the leap up to partial mash brewing. I have a few questions thou.

OK. Say I have an all grain recipe that calls for 9 lbs of 2-row and 1 lb of crystal with an estimated OG of 1.050

I have a 3-4 gallon brew kettle. I figure I can hold a maximum of 5 - 6 lbs of grain plus the nessicary water in my small mash tun.

I know that I am going to need my boil to have a gravity reading of 1.070 in order to dilute to the right OG once I top off to 5 gallons with water.

How do I adjust the grain bill to work with the smaller boil?

How can I figure out how much malt extract I will need to make up for the amount of grain that i cant mash?

Also, if i take a sample of my boiled wort, and the gravity isnt where it's supposed to be, is there a way to figure out how much dry malt to add to make up for it?

I know this is a little long winded, but I had to get all these questions out while they were still fresh in my mind.

Thanks everyone

-Matt
Dutchbrew
Light Lager
Light Lager
Posts: 12
Joined: Mon Sep 19, 2005 11:52 am
Location: Chicago, IL

Re: first partial-mash brew

Post by Dutchbrew »

<How do I adjust the grain bill to work with the smaller boil?>

your boil should be around 1.070 at a 4 gallon boil already assuming that recipe is a 5 gallon batch. adding more or taking away malt is the only thing that will affect your gravity as it will stay constant when you add water

<How can I figure out how much malt extract I will need to make up for the amount of grain that i cant mash?>

its approximately .75 lbs of extract per lb of grain

<is there a way to figure out how much dry malt to add to make up for it?>

you will have to adjust your gravity reading if the wort is hot. i know at 120 degrees you would add something like .016 but ray danials book "how to make great beers" has a correction chart in it. otherwise cool it to 60 degrees.
total gravity = 1- gravity / volume
(1-gravity from boil) X starting volume / final volume = OG
-so say you add all your ingrediants to start the boil and your gravity = 1.072 so 1-1.072 = 72 X 4 gallons = total gravity of 288 / 5 gallons = 57.6 so 1.058. now take your total volume (288) divided by OG in recipe (50) and you will have the final volume you need for a 5 gallon batch with an og of 1.050 (288/50 = 5.76 gallons) in this case you could spoon out some from your pot to get the gravity lower, or you can stick with 5.76 gallons if you have 6.5 gallon primary fermentor bucket and you will have extra beer :P .

Maybe somebody can help me with how much extract to add if the og turns out lower than 50. there is an equation in the book but i havent memorized it as i usually just adjust my finishing volume instead of adding or subrating malt. you would then have a batch a bit smaller than 5 gallons if you can live with it.
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