Easy Partial Mash Brewing (with pics)

[smitty8202]

Partial boil refers to the amount of water being boiled. If you want a 5 gal batch of beer you would only boil say 2-3.5 gallons of water. That way when you add your grains and your at max capacity of your kettle you don't overflow your kettle

 

[DeathBrewer]

This is a long thread so I apologize if someone already addressed this, but I'm wondering why you would add all of the extract at the beginning of the boil if you're only doing a "partial boil"? Thanks!

Some people don't. The more sugars you have in solution (the higher the specific gravity of your wort), the less utilization you get out of your hops. Many recipes call for "late-addition" extracts so that the hop amounts are the same whether you do a full boil all-grain or a partial boil with some extract. In other words, follow the recipe or plan accordingly if you change it.

I always tell people to plug a recipe into BeerSmith and play with the pre-boil volumes (uncheck that silly "calculate boil volume box) to see how it changes your IBUs.

Partial boil simply means not boiling the full amount (typically 6.5-7 gallons down to five over the course of an hour) and topping off instead, after the boil is finished.

If you do a partial boil, be sure to use pre-boiled water for your top-off.

 

[DPveritasGold]

Some people don't. The more sugars you have in solution (the higher the specific gravity of your wort), the less utilization you get out of your hops. Many recipes call for "late-addition" extracts so that the hop amounts are the same whether you do a full boil all-grain or a partial boil with some extract. In other words, follow the recipe or plan accordingly if you change it.



I always tell people to plug a recipe into BeerSmith and play with the pre-boil volumes (uncheck that silly "calculate boil volume box) to see how it changes your IBUs.



Partial boil simply means not boiling the full amount (typically 6.5-7 gallons down to five over the course of an hour) and topping off instead, after the boil is finished.



If you do a partial boil, be sure to use pre-boiled water for your top-off.

Great info! Thanks!

 

[DPveritasGold]

Great info! Thanks!

 

[madbewer]

Can you provide a list of the ingredients?

 

[DeathBrewer]

For what now? To play with BeerSmith? You can use any recipe. Find one in the database here that lists IBUs and compare.

 

[jlinz]

Great thread. I can't wait to try the dunkelweizen for my next beer! Maybe somebody can help me out here and answer a couple questions: How do I know how much grain to mash in any given recipe? And what do I do differently when doing a full boil? Do I just add the extra water to the brewpot after adding the water from the mash and sparge?

 

[DeathBrewer]

I'd suggest getting some software like BeerSmith to help you design recipes. I always mash 5-6 lbs of grain with this method and adjust the amount of extract to meet the needs of the recipe and get the right alcohol content. The software really helps with calculating the right amount of hops to add and creating the right balance.

 

[unionrdr]

Yeah, I like BS2 for those reasons as well. It makes it easier to get the various hop & malt additions right for the style selected by using the bar graph it creates in real time. I hit my personal max with the kottbusser recipe. 7 1/2lbs of grain mashed in my 5 gallon SS kettle. After sparging to boil volume, it's turning out rather well. But 4 gallons is about max in a 5 gallon kettle if you're careful.

 

[Tippsy-Turvy]

Have you tried any really thin mashes with your approach? Just wondering how you sparged with so little resultant water.

I'm planning a thin mash for an upcoming IPA (say, 2 quarts/lb) and from my water calculations, that doesn't leave much water for the sparge step. I still want a sparge step as I'm finding my efficiencies are always > 80% this way. Am thinking I might add back some wort from the mash just to make the sparge easier to stir?!?!

Thanks again for your thread, DB. It was seminal in my move from extract to PM & AG.

 

[DeathBrewer]

Using the "batch sparge" method (as opposed to the "fly" or "rinse" sparge), you could certainly leave some of the mash liquid or pour some back in for the sparge. I do not know how this will affect efficiency. I tend to think that using a thicker mash and rinsing with more water will get you a higher efficiency. Doing a "dunk" sparge (batch) in part of the water and then a "rinse" (fly) with some remaining water seems to get me the highest efficiency with this method.

I have far too many names for rinsing sugar out of grain.

 

[unionrdr]

If I partial mash with 2 gallons of spring water, I'll dunk sparge with 1 1/2 gallons to get 3 1/2 gallons +/- of wort for boil volume. I've tried sparging with part of the main wort, & it worked ok in conjunction with regular sparge water amount. So either way is good to me.

 

[Bosh]

Great thread. Think I`ll do this with two partial boils going at the same time on different burners as my stove can`t handle a 5 gallon boil. Will probably be lazy and boil the mash and sparge water separately and split the hops between them unless there is some reason now to do this.

You recommend against heating the pot while mashing. How vital is this? I don`t think SWMBO would be pleased by me wrapping a cooking pot in her blankets...

 

[unionrdr]

I couldn't maintain the mash temp on the stove. So I wrap the mash tun in my quilted winter hunting coat.

 

[DeathBrewer]

I've used old beach or bathroom towels. Anything helps.

 

[lazarwolf]

Great thread. Think I`ll do this with two partial boils going at the same time on different burners as my stove can`t handle a 5 gallon boil. Will probably be lazy and boil the mash and sparge water separately and split the hops between them unless there is some reason now to do this.

You recommend against heating the pot while mashing. How vital is this? I don`t think SWMBO would be pleased by me wrapping a cooking pot in her blankets...

If your stove is like mine, you will find that after the mash is over, you can actually boil full volume on your stove. Just separate it into two pots. 3.25 gallons each. Your wort doesn't know where it is being boiled. It is called "texas two step" and there are lots of threads about this method.

I used to apply gentle heat to my stovetop mash brews all the time. I have a small cake pan for a false bottom. I never had any problems.
https://plus.google.com/u/0/photos?pid=6136918768239605570&oid=109844831557777229002

You can also just mash in one of these. These were $6 at Walmart.

Or you can do it on your stove top like this, with a false bottom.

 

[freisste]

Or put the pot into your oven (after heating to the lowest temp setting and turning off).

Assuming it will fit.

 

[Bosh]

Pot won't fit in oven. Not close

lazarwolf: images aren't appearing but hard to get some stuff in Korea...

But what I do have is a big 5 gallon or so dumpling steamer pot (with false bottom with big piles in it to let steam rise to steam the dumplings) and a smaller 2.5 gallon or so soup pot. The soup pot is solid with big thick walls while the dumpling steam is thin and crappy.

Am thinking of mashing in the dumpling pot, using the false bottom, wrapping it in aluminum foil to keep heat in and keep if over really low heat and check temp periodically.

Then sparge the in the soup pot. It's not really big enough but better than nothing. Then try to split the wort between the pots and boil the hops and have some boiled water on hand to top off.

 

[lazarwolf]

Perfect for partial mash. And with a false bottom? You're all set. Goodman plan

 

[lazarwolf]

By the way pm brewers, I am working hard at posting actual partial mash recipes on brewtoad. Just type in " ( real partial mash ) ". With the parenthesis.

Also my brew partner and I both got Cajun injector electric turkey fryers... best rig ever for partial mash. Mine was $80.

 

[Others]

Ive always had great luck doing my partial mash brews by using a 3 gallon igloo water cooler. Inexpensive and seems to hold the temperature for the full hour.

 

[dasjules]

This is a method I've been looking for ! Thanks for helping out a new brewer

 

[unionrdr]

Hm...use my biab grain bag inside that one to simplify maybe? The three gallon size might be a bit small for some of my bigger PM's. But I could use something that holds temp more accurately. Intriguing...

 

[CoffeenCraftBrewer]

Here are a few questions for those on the forum. Thanks to DeathBrewer for the photos and description of how to do this. I was slightly misled and or assumed by the response from my LHBS, BIAB could not be done at home with a 5 gallon pot. He or I was wrong. Guess one should not assume!

After brewing my first Partial Mash I had a big issue.
I missed my OG, bad, by 14 points. 1.032 instead of 1.046. I think that means poor conversion rate of my grains.
Here is what I did that I believe to be relevant, aside from testing the ph of my water, which is filtered:
1. I held my mash temp at 152F
2. I did not mash out to 170.
3. I fly sparged at 60 min.
I removed the BIAB w/grains to separate pot at 60min., sparged with 3 gallons of water - some heated some not. By sparge I mean pouring slowly from a glass pitcher over top of the grain bag. Then I squeezed as much out of it as I could. The grain was so hot I needed latex gloves.
3. I added my LME at boil, then hops per instruction.
4. I used 6 quarts of water at start for the 4.5 lbs. grain.

I thought I was doing good when I ended up with 4.5 gallons to boil.
I only had to top off with 1.5 gal. pre-boiled water after 60 min. boil.
Though some online assistance, I learned I could add honey with little adverse affects and raise my OG by 8 points.
I ended up adding about a pound of honey once wort cooled. I aerated all of the crap in the glass carboy, like the Hulk, before each reading (2x) and factored in actual temperature of wort.

This leads me to think next time I do this:
A. Mash for longer than 60 min. - probably 90 to be on safe side.
B. Mash out for the last 10-20 minutes of mash at 170F. (bought a ss colander for false bottom)
C. Batch sparge (tea bag style) in 170 degree water while my wort is increasing to boil temps. 10-15 min.
(combine lauter and wort, then boil)
D. Iodine test Wort at end of 60 min. boil
E. Ask LHBS to mill grains a second time to ensure grains are cracked
F. Have some DME on hand in case my OG is short.

What are your thoughts on why my OG was so far off? What effect does missing my OG have? Lighter alcohol content than intended? Should I worry about missing the recipe OG?

Thanks again for your post and photos. Without them, I would still be on the LME/DME route. This involves way more learning and hence the craft. Cheers!

 

[Bosh]

Did your adjust your OG reading for temperature? I didn't my first time and got freaked out by my apparent horrific efficiency.

 

[CoffeenCraftBrewer]

Yes, I added a point or two for that. First reading was at 70F so only added a point at 60 deg. calibration.

 

[Deckers_Beers]

Thanks for the post! I'm definitely going to be trying this method out for my next batch.

I've tried doing a partial mash at 150* for 45 minutes before, but I'm pretty sure I got almost nothing out of it in terms of conversion. I think not sparging was my problem? Either way, I'm going to get another stock pot and use this method for the lager I'm planning to brew next weekend.

 

[unionrdr]

I usually mash at 153F. for darker beers, I mash at 155-156F. Since I mash a lot of grains, as much as 8.3lbs in 2 1/2 gallons spring water, I batch sparge in 1 1/2 gallons at 168F for ten minutes. Using a nylon grain bag allows me to stretch it over the lip of the kettle to stir the grains. My OG's have gone up as a result. These two volumes give me about 3 1/2 gallons boil volume in my 5 gallon kettle.

 

[lazarwolf]

Partial mash is my favorite method of brewing. I make consistently excellent beer with PM. I use an electric turkey fryer. I BIAB my grains in 3 to 4 gallons of water depending upon the amount of grain I am using. I mash at 150 for "lighter beers" and up to for thicker darker beers. I split my remaining sparge water. Into one pot goes 2 gallons of water and the DME (always extra light DME if Possible). Into the other pot goes my sparge rinse water, usually about 2 gallons.
At the end of the mash, I pull the bag/ basket. I add the DME water. Then I rinse to volume. I almost never miss my targets by more than a point or two.
You truly can not tell the difference between Partial Mash and All grain.
I have loads of recipes at my blog. And on brewtoad if any one is interested. I
I just sampled a cream ale that is truly the best I have ever had. Made partial mash right on my kitchen counter.

 

[Dirt_McGirt]

I just did my first partial mash / BIAB using a tweaked version of this method last night to brew a Kölsch, and it worked great. Took a little longer than I'm used to (esp. since I forgot to turn the burner on for my mash water after pre-heating my sparge water), but I'm sure it'll get faster as I dial in the process.

I was a bit worried about my efficiency matching the recipe I was working from, so I copied the 75 min. mash at 149 that was called for, and did a 15 min. sparge with a mix of dunk and pour over method. I was pleasantly surprised when my OG reading came in dead on at the 1.050 I was shooting for. I'll definitely be using this method again - I was especially surprised how well I was able to control the mash temp in the brew pot on my stove. Turns out I can return that new cooler back to Lowe's, after all. That's $40 I can use on another batch!

Thanks for a great thread!

 

[cholder777]

Do you recommend oxygenating the wort after adding the yeast by shaking it? I have seen it in a few videos on youtube. One guy shook his for 3 minutes straight!

 

[unionrdr]

I pour the chilled wort through a fine mesh strainer to not only get the gunk out, but aerate it as well. Then, since I also top off, I use my paddle to stir vigorously for a few minutes before taking hydrometer sample. Since I top off with fridge chilled spring water, that also helps, especially when poured in the primary from a decent height.

 

[Deckers_Beers]

I pour the chilled wort through a fine mesh strainer to not only get the gunk out, but aerate it as well. Then, since I also top off, I use my paddle to stir vigorously for a few minutes before taking hydrometer sample. Since I top off with fridge chilled spring water, that also helps, especially when poured in the primary from a decent height.

I do the same thing! I leave the water I'll use to top off in the fridge, and this works wonders for getting the wort under 75* before pitching (I try for 68*), which can be a lengthy process while brewing in the summer in southern California...

 

[gok]

tnx for the pics.
step 5: using it again? for what?

 

[unionrdr]

I do the same thing! I leave the water I'll use to top off in the fridge, and this works wonders for getting the wort under 75* before pitching (I try for 68*), which can be a lengthy process while brewing in the summer in southern California...

I chill mine to about 75F in the ice bath, then when topping off with the chilled spring water, I can get the temp down to 65F or lower. This also produces some decent cold break as well.

 

[Zigs6]

It may have already been covered in the other 1 million previous pages, but is there a flaw in this idea? I'll be doing a BIAB partial mash in my 5 gallon igloo cooler this weekend. After the mash is done, couldn't I just tea bag the grain bag in my 30 gallon boil kettle that is already heated to 165 F. My boil kettle will have around 15 gallons of water already heated up for my 15 gallon batch. Why can't I just rinse by grain bag in there to maximize extraction? Will 12 pounds of grain in a huge bag be harmed in some way if I do that?

 

[unionrdr]

No, it'll be fine. But only tea bag, or " batch sparge" with just enough water to get you to your boil volume. I do it for 10 minutes @ 168F.

 

[matthaney74]

Death- Maybe this question was asked and answered along the way thru the post, but I searched and searched, but didn't see it.

In some PM instructions out there I see an extra step of "mashing out" by raising the temp in mash kettle to 170 after the hour mash... and then sparge. In your PM recipes posted and in your pic-tutorial it wouldn't seem you use a mash out step if you sparge in 160-ish water to get conversion to continue? Insight to give? Is there some chemical importance to the mash out step as it relates to PM brewing?

 

[RM-MN]

Death- Maybe this question was asked and answered along the way thru the post, but I searched and searched, but didn't see it.

In some PM instructions out there I see an extra step of "mashing out" by raising the temp in mash kettle to 170 after the hour mash... and then sparge. In your PM recipes posted and in your pic-tutorial it wouldn't seem you use a mash out step if you sparge in 160-ish water to get conversion to continue? Insight to give? Is there some chemical importance to the mash out step as it relates to PM brewing?

I'm not deathbrewer but I have answered this question before. If you do an all grain batch and if you decide you need to fly sparge (which should take between 30 to 60 minutes) you would do a mash out step to denature the enzymes so they wouldn't keep working while you did that extended fly sparge. Since you are doing a partial mash, you will likely be bringing the wort to a boil soon which takes the place of the mash out by denaturing the enzymes quickly. You would be removing the grains and perhaps pouring some water over them to capture more sugars (pseudo batch sparge) and then going to the boil.

 

[Mothman]

Newb questions, which may be answered elsewhere in this thread, but it's sooo long! lol.

OP says he does partial boils and adjusts the hops accordingly... am I understanding correctly, this means he is using recipes that call for a full boil, and adjusting due to using a smaller brew pot? And the hops adjustment is done via a tool like Beersmith?

And where he says he shoots for a certain starting gravity, but doesn't test this until everything is topped off... am I understanding this to mean that he figures his process will get him to the desired gravity... but if it's off, he just leaves it, as there is nothing that can be done to alter it once topped up in the fermenter?