Author Topic: First partial mash....and Im confused.  (Read 1503 times)

Offline whitey

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First partial mash....and Im confused.
« on: August 03, 2011, 06:07:39 AM »
So, I did my first partial mash yesterday. Pumpkin Ale kit from Austin Home Brew. Followed the recipe, and ran into some problems.

1) I had pellet hops, and a new plate chiller. In the past, I was cooling the wort in an ice bath, as a result the hops residue and other trub settled below the valve in my brew pot. So when it came to pour off, I didn't have a problem with the residue getting into the primary. Now, running hot wort thru the plate chiller has the problem with trub and hops still in the mix. What's the best way to address this?

2) Recipe called for a combination of 3 gal of liquid once sparge and addition before boil. Once boiled, i was left with 1.5 gal in the  primary, and easily a gallon below the valve in the pot. Does the liquid requirements on paper need to compensate for this difference?

3) After the mash I added 4 lbs of LME, and once my 1.5 transfer was done, I began to add the water to get my OG. I was only able to add 1 gal before I hit OG. So I have 3 gal of wort tormenting. Not cool. Clearly, I didn't mash quite right. So, is the 1 gallon of liquid that was below the valve in my pot the reason? Do I need to add 1 extra gal initially to compensate?

Looking forward to the input.
« Last Edit: August 03, 2011, 06:25:00 AM by whitey »
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Re: First partial mash....and Im confused.
« Reply #1 on: August 03, 2011, 07:40:53 AM »
1) You'll also find that excess trub and hops will clog your plate chiller.  This is usually fixed by a combination of whirlpooling (stirring to get trub/hops to accumulate in the center) and using a tube to draw wort from the edge of the pot, or using various screens or false bottoms (google bazooka screen).

2) Your using a plate chiller with a 3 gallon boil? This is overkill. How big is your pot? I assume quite large if you have a valve on it. I'd boil with as much water as you can for your pot. Yes, most recipes need to be adjusted for the amount of wort left in the kettle below the valve. This adjustment includes both water and malts, since that water also contains lost sugars.

3) Speaking of lost sugars. If you transfered 1.5 gallons to your fermenter and left 1 in the pot, that is 40% of your sugars lost that didn't make it to the fermenter. By coincidence (not really) 3 gallons is 40% less than 5 gallons. The more wort you're boiling, the less the effect will be of leaving behind some wort in the pot. Another part of the solution would be to use an angle tube of some sort, attached to the valve inside your pot, so that less wort is left behind.
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Offline whitey

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Re: First partial mash....and Im confused.
« Reply #2 on: August 04, 2011, 12:30:12 PM »
Well Jimmy, as I'm sure you realised by all the n00b questions, and the title, this is my first crack at a partial mash. So things you take for granted, I'm still learning about. As always I'm grateful for anyone's insight and help, however after reading your response, which had a lot of good info, I came away from it feeling like child being admonished by an adult for not understanding how a fuel injection system works.

Perhaps a plate chiller is over kill, in the past with all my extract brews, I used close to a 5gal boil and became tired of waiting an hour to chill my wort in an iced bath tub, and a regular submersible wort chiller costs $30 bucks less than what I paid for the plate chiller, but most importantly I wanted it. I don't even understand why its important whether having one is over kill or not. Also, the recipe called for 2.5 gal to mash (more like steep if you ask me) the grains and another quart and a half to sparge them.

I don't have a large pot, I think it'd a 7 gal entry level pot, I added the valve at the suggestion of my lhbs owner. It had a bazooka screen of sorts but got clogged up by the hops pellets in the wort. So I pitched it. Folks on the AHA forums suggested leaf hops in a hops  bag, I was hoping to corroborate that once more by my question. Unless a brand name bazooka screen will perform better than the generic one I had before.

Is there a formula to ensure the correct efficiency and hops exposure considering the doubling of the boil volume,?  I ask because I have another kit for an Oktoberfest which I don't want to screw up.

Once again, I'm always grateful for insight and instruction.
« Last Edit: August 04, 2011, 12:51:05 PM by whitey »
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Re: First partial mash....and Im confused.
« Reply #3 on: August 04, 2011, 12:48:24 PM »
Hey, sorry... I didn't mean to come off sounding that way.

I wouldn't worry about changing the hops additions, any change would be very small.  7 gallons is a large pot and you can use pellet hops in a hop bag too, just make sure you use a big one. They'll absorb water and expand a lot.
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Re: First partial mash....and Im confused.
« Reply #4 on: August 04, 2011, 01:24:42 PM »
Sounds like you're using the same pot and valve for the partial mash as you used previously for all extract batches.

If that's true, you shouldn't be losing any more wort than previously, so I wouldn't expect you to see such a difference.  Maybe I'm mis-reading your post.

Perhaps the efficiency of your mash is lower than what the recipe calls for?  What temp did you mash at and for how long?  Are you sure your thermometer is calibrated? 

Is there anything else different for this batch from previous?  Do you usually do Austin kits?  Or do you use recipes?  It could be that the kit as formulated is not ideal for your system and you need to tweak something.

My hops always go in hop bags.  My grains for partial mashes go in grain bags.  When I transfer to the fermenter, I run the wort through a mesh filter to catch all the mess and I get darn near 100% of the wort.

If anything, I often overshoot my target gravity.  But I rarely consider that a bad thing.  But I've been doing partial mashes for years and am very familiar with what to expect from my process.
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Offline dirk_mclargehuge

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Re: First partial mash....and Im confused.
« Reply #5 on: August 04, 2011, 01:31:31 PM »
So, I did my first partial mash yesterday. Pumpkin Ale kit from Austin Home Brew. Followed the recipe, and ran into some problems.

1) I had pellet hops, and a new plate chiller. In the past, I was cooling the wort in an ice bath, as a result the hops residue and other trub settled below the valve in my brew pot. So when it came to pour off, I didn't have a problem with the residue getting into the primary. Now, running hot wort thru the plate chiller has the problem with trub and hops still in the mix. What's the best way to address this?

2) Recipe called for a combination of 3 gal of liquid once sparge and addition before boil. Once boiled, i was left with 1.5 gal in the  primary, and easily a gallon below the valve in the pot. Does the liquid requirements on paper need to compensate for this difference?

3) After the mash I added 4 lbs of LME, and once my 1.5 transfer was done, I began to add the water to get my OG. I was only able to add 1 gal before I hit OG. So I have 3 gal of wort tormenting. Not cool. Clearly, I didn't mash quite right. So, is the 1 gallon of liquid that was below the valve in my pot the reason? Do I need to add 1 extra gal initially to compensate?

Looking forward to the input.

1) when you finish the boil, stir your wort in one direction for a few minutes.  Slap the lid on it, put it where you won't be moving it until it's empty, and let it sit for 15-20 minutes.  The hop trub and hot break should form a cone in the bottom of your kettle, away from your spigot.  At least, that's the plan.

2) You need a false bottom with a pick up tube for your kettle to get that last gallon or so or wort.  That's too much left in the kettle.  If you add water to what's in the fermenter to get to five gallons, your OG will be too low.  Or you could get a stainless racking cane and some sort of clamp to siphon the remainder out, and leave the cone of stuff behind.

3) If you want to leave "a good gallon and a half" of wort in your kettle, then yes, add more water up front to compensate.  You might have to add more LME to hit your OG.

The first few batches will teach you mostly about your equipment--what it can and can't do.  The next few will help you become consistent.  Fermenting 3 gallons at the correct OG is the right thing to do for the beer, but not the best for you wallet.