Homebrewers Association | AHA Forum

General Category => All Grain Brewing => Topic started by: andrew000141 on January 01, 2013, 04:07:45 AM

Title: first AG questions
Post by: andrew000141 on January 01, 2013, 04:07:45 AM
i did my first AG on christmas, it was my LHBS moose drool clone. I did a 3 gal batch instead of a 5 gal because i only have a 5 gal kettle as of now. Anyways had a few questions.

1. the O.G. for the kid was 1.056-1.057 and i got 1.071, i batch sparged and there was roughly 7lbs of grain in the mash tun, the amount was scaled down from the 5gal recipe, i feel like thats a huge gap for just efficiency . Is there another factor im missing?

2. cleaning my mash tun was quite the endeavor how do you guys go about doing it?

3. how do i calculate efficiency? and if i was to make my own recipes what should i assume for most base malts ppg if it is unknown

my brew day actually went very smoothly besides for being shocked at my 1.071 gravity
Title: Re: first AG questions
Post by: tygo on January 01, 2013, 02:25:15 PM
1.071 would be somewhere in the 82-87% efficiency range depending on the exact recipe.  That's on the high side but easily achievable, especially for a smaller batch.

Cleaning the mash tun is what it is.  I just lift and dump.  If there's too much grain to do that easily I shovel it out until it gets light enough.  Then I hose it out.

Base malts are in the 35-37 pppg range.

Title: Re: first AG questions
Post by: hopfenundmalz on January 01, 2013, 02:49:26 PM

2. cleaning my mash tun was quite the endeavor how do you guys go about doing it?

If you ever have to scoop out the spent grains from a 7 bbl mash tun with no manway on the hottest day of the year in a hot brewhouse, the amount we deal with is "no problem". Just saying.
Title: Re: first AG questions
Post by: malzig on January 01, 2013, 02:49:52 PM
1. It looks like NB calculated the OG on only ~70% efficiency.  If you got good conversion efficiency and the 85%+ lauter efficiency you would expect from a batch sparge of a malt bill that large, ~1.070 is reasonable (Edit: Sorry, Tygo, I see you already covered this while I was typing).  Also, efficiency measurements are dependent on very accurate gravity and volume measurements, so if you were off a bit on either of these you might get this gravity reading without such excellent efficiency. 

That is higher efficiency than most brewers get on their first mash, but it is what I would expect from my brewery.  Make sure that you have an accurate way to measure volume and check that your hydrometer reads 1.000 in water.

2. I turn my tun upside down into the compost bin then rinse it out with the hose (I use the handheld shower in the winter).  Takes about 2 minutes.  What made it so difficult?

3. For calculating mash efficiency (a result of combined conversion efficiency and lauter efficiency), it is best to use the actual potential of the grain, but most brewers don't usually have that information.  Most base malts have a potential of 36 points per pound per gallon, after correcting for moisture content.  Crystal and roasted malts are usually in the 29-34 range.  For an all base malt recipe, 36 is a good value to use for estimating efficiency.  For a recipe with a lot of specialty malts, 35 isn't a bad value for an estimate. 

Mash Efficiency = (gravity x wort volume) / (grain potential x weight)
(multiply time 100% if you want it in %)

For estimating the expected gravity of your beer, you take the potential of your grain and correct for your efficiency:
Gravity of beer = mash efficiency x (grain potential x weight) / volume

Edit: Kai's site will do a great job giving an understanding of mash efficiency (http://braukaiser.com/wiki/index.php?title=Understanding_Efficiency) and an effective approach for troubleshooting mash efficiency (http://braukaiser.com/wiki/index.php?title=Troubleshooting_Brewhouse_Efficiency).
Title: Re: first AG questions
Post by: davidgzach on January 01, 2013, 03:48:08 PM
Congrats on your first all grain!  If you got to 85% efficiency, well done!
Title: Re: first AG questions
Post by: euge on January 01, 2013, 06:53:50 PM
Congrats on your first all grain!  If you got to 85% efficiency, well done!

My words exactly!

A can of worms has been opened...

But no fear it is mostly straightforward though it may take some time to reach a comfort level. You could adjust your brewhouse efficiency in your calculations based on this one session. However, maybe a few more brew sessions to dial things in a bit? Take some good notes.

I've found that the thicker your mash- as you start to max out the tun and effeciency and conversion suffers so must be planned for. When pushing the limits an effective technique is to mash longer with some good stirring and to sparge a third time if you batch-sparge.

Title: Re: first AG questions
Post by: andrew000141 on January 01, 2013, 08:00:30 PM
wow thanks for all the replies guys! i dont know why i had such difficulty with my mash tun i threw it out where i used to with my specialty grains and then i just could not get all the extra grains off the side and bottom(i may have to use that shower handle idea). This actually wasnt NB's caribou slobber it was my LHBS's clone, the owners of the shop wrote "beer captured" and "clone brews". I ordered a refractometer off amazon with a gift card i received a few days ago for first/second runnings gravity and preboil gravity and such so next time ill have enough time to make adjustments. now i just have to figure out what to make next!
Title: Re: first AG questions
Post by: theDarkSide on January 02, 2013, 02:18:55 PM
This is the grain bill from the 6 gallon Can you Brew it? version.  Does their grain bill look similar to this, when you adjust it down for 3 gallons? 

11 lbs 1 2.5 oz  Pale Malt (2 Row) US (2.0 SRM)  86.9 %
1 lbs 5.8 oz      Caramel/Crystal Malt - 80L (80.0 SRM) 10.1 %
6.1 oz             Chocolate Malt (350.0 SRM)  2.8 %
0.4 oz             Black (Patent) Malt (500.0 SRM) 0.2 %

As far as my mash tun, I do the same as above...dump and rinse.  Maybe I'll take it apart once a year and give it a thorough cleaning ( 72 coleman xtreme rectangular cooler - blue of course  ;) )
Title: Re: first AG questions
Post by: weithman5 on January 02, 2013, 02:48:18 PM
i do 2-3 gallon batches.  i use a grain bag in my mash tun and just lift the whole thing out.
Title: Re: first AG questions
Post by: kgs on January 06, 2013, 01:34:40 PM
Did you adjust for temperature for your hydrometer reading? That won't account for a lot, but it could count for a couple of points. Also, as a small-batch brewer, I agree that a small variation in volume can lead to wide variations in gravity (something that also works in your favor if you want to tweak your gravity pre- or post-brew).

I routinely mash batches that size in my 5-gallon mash tun. I carry the tun to our composting bin, dump it out, then rinse it out on the deck with a garden hose (with the spout on the tun open so the spout gets rinsed). Not a deal, as long as I do it within the hour or so, before the grain starts to stick.
Title: Re: first AG questions
Post by: repo on February 09, 2013, 09:33:57 PM
There is no way of knowing your mash efficiency, it is not calculated with o.g. and batch size.
You need your preboil volume and gravity, or your post boil volume and o.g.
Your batch/fermentor volume will be less than your post boil volume due to a number of things, some of which will be unique to your system.

I would need at least 3.5 gallons post boil on my system for a 3 gallon batch. Meaning at 36 ppg possible from the "7ish" #s of grain you would have 252 points possible(generous). I would need 248.5 of them to have 3 gallons of 1.071 wort, or about 99% mash efficiency.
This should illustrate how very accurate detailed measurements are needed to start determining your diffferent efficiencies.