What's Wrong With My Partial

[RobboMC]

I started with 4.5 litres of water at 70 deg C, and added 1 kg of Vienna grain and 0.5 kg of Crystal grain,
temp dropped to about 55 deg C

Held temp at 65-68 deg C ( metal backed liquid in glass thermometer ) for 60 minutes, stirring almost continuously,
but slow heating on my hotplate.

Removed grain ( used a grain bag ) washed grain with about 1 litre amount of water heated to 75 deg C.

Ended up with around 5.5 litres of wort; measured the gravity and it was 1030.

Now I've used 3.3 lbs in 1.5 US gal, so I have ended up with a paltry 13.6 ppg.

What have I done wrong? How can I increase my efficiency and get more lovely grain flavours in my partial?

 

[buttersd70]

The thought that immediately comes to mind for me (bearing in mind that I don't do biab and know little about it, and this is basically a small scale biab) is not enough water for the sparge; you probably left a lot of luverly sugars in the grain.

Other possibility is too coarse a crush, and incomplete conversion as a result....next time round, this can easily be checked with an iodine test.

 

[RobboMC]

Thanks buttersd,

This time round I did something of a batch sparge by dunking the full grain bag into more hot water, swirling the grain around a bit to wash it, and keeping the runnings. The second pot contained some loverly dark coloured wort of obvious gravity and strength.

I also got some thin wort from a third pot of water, but didn't count this in my efficiency calculation.

In the end I got about 7.5 litres of 1050 wort from 1.5 kg ( 3.3 pounds ).

How do I calculate the ppg? Do I use a 3.78 litre US gallon?

If yes, then 50x1.98/3.3 = 30 ppg which seems too good to be true for a beginner
but means my mash conditions are on the money.

Grain was 2/3rds Munich and 1/3 Medium Crystal, so total potential about 35 ppg, leaving my efficiency at 85%.
Seems too good to be true, but all the measurements were only rough.

If no, then it's only 1.65 gallons and 50x1.65/3.3 = 25 ppg, which is still Ok but needs improving.

The next step would be to weigh grain and calibrate volume in boil pot.

Also, am I risking HSA by pouring the warm wort ( about 60-70 deg C ) into the boil pot?
I've read it's more a problem above 80 deg C.

 

[buttersd70]

Robbo, yes you would use US gallons for working out ppg.
so (points X gal)/lb = 50x 1.98 / 3.3 =30ppg. So yes, you are correct.

From the POV of efficiency, you divide total points by the max potential of the grains used. (potential a Xweight/vol +....etc) which appears to be what you've done. Munich is more likely to be around 38ppg if it's JW or Weyermann.The crystal would be around 34-35ish ppg. Even so, this still gives 81%. Good stuff indeed. :super: Ecellent efficiency for a partial.

HSA? some say it's a myth, some say it's a real threat....I won't get into that one. You need to get the wort out somehow, just do it as carefully as you practically can to minimise splashing, and then everyones happy. If you take sensible, practicle precaution, you should be fine.

 

[pint of lager]

As a partial ag brewer, you are aiming to get some of that malty goodness into your beer. Do not worry too much about efficiency. Only the people that fly sparge and have a very well tuned system achieve high efficiencies.

Next time, aim to hit your mash temp a bit closer, try having your strike water about 10 degrees above your mash temp. With the temperature drop you had, you may even want to try closer to 80 degrees strike water temperature.

HSA, as a partial ag brewer, do not fret too much about it. As your techniques and skills improve, you will want to take steps to minimise.

 

[hazard]

I started with 4.5 litres of water at 70 deg C, and added 1 kg of Vienna grain and 0.5 kg of Crystal grain,
temp dropped to about 55 deg C

Held temp at 65-68 deg C ( metal backed liquid in glass thermometer ) for 60 minutes, stirring almost continuously,
but slow heating on my hotplate.

Removed grain ( used a grain bag ) washed grain with about 1 litre amount of water heated to 75 deg C.

Ended up with around 5.5 litres of wort; measured the gravity and it was 1030.

Now I've used 3.3 lbs in 1.5 US gal, so I have ended up with a paltry 13.6 ppg.

What have I done wrong? How can I increase my efficiency and get more lovely grain flavours in my partial?

I've started doing partials a few months ago, I have used beer smith to calculate OG and after a bit of a disaster with the first one, I am now matching the Beer Smith estimated OG to 1 or 2 points, based on 75% efficiency. Basically, I treat a partial just like a full AG mash, and I think your process will leave too much sugar behind.
Firstly, to extract everything, you need the right equipment. I bought a plastic bucket with false bottom from G&G for $50 at their last 20% off sale. My process is:
1. Use 2.5 litres water for each kg grain. Beer Smith tells me to heat this water to 74% to get a medium body beer (approx 65 deg).
2. Put the lid on and pull sleeping bag over the mash bucket to keep warm for 60min
3. After 60 min add approx 1 litre water for kg grain, at 91 deg, to bring mash temp up to 80 deg. Beer Smith provides exact amout.
4. Leave for 10 min, then recirculate wort until clear and collect first running.
5. Add sparge water - same amount as initial lot ie 2.5 litres per kg of grain, at 80 degrees. Lid back on and sleeping bag on, and leave for 10 min.
6. recircualte and collect second running. Done!!
7. Include all specialty grains in the mash, to maximise extraction.

Washing the grain bag under running water (or dunking it) will not get the same efficiency.

My kettle is only 19 litre, and the largest partial I have done was about 2.75kg grain which just about filled the kettle. This was an English ESB. I added 2 kg of extract and following the boil I managed an OG of 1060 and FG of 1014 (Beer Smith estimated 1062 and 1018 @75% efficeincy, so I am very happy with this outcome). Whilst elapsed time for this process is a few hours, there is plenty of rest time to read the paper etc. Not too hard.

Hope this helps.

 

[buttersd70]

Haz
Yes, your method is a smaller scale variant of a 'regular' mash. It's a good method, it works, and no doubt you are getting good efficiencies.
Robs method is a smaller scale variant of BIAB method (slightly hybridised). It's a good method, it works, and he is getting good efficiencies.

and I think your process will leave too much sugar behind.

This is obviously not the case. If he's getting 81% efficiency, how on earth can that be considered leaving too much sugar behind?

If the glove doesn't fit, you must acquit....

 

[Bribie G]

Although I'm AG brewing my UK style beers I still make a partial 'fake lager' that I really like. Nowadays I do a full 5kg brew and split the wort into four cubes and use one cube for each brew, but when doing individual partial mashes I used:



It's a 9 litre Decor container sold in all Woolies stores etc, and it fits neatly into my Esky brand sports esky where it sits in a 70 degree water bath, mashing at 68. I usually have to strike at around 78 but there's heaps of room for quick adjustment using boiling or cold water. I just about fill the Decor and adjust the water bath only a couple of times over the hour using boiling water. Easier than stove top and quite cheap if you already have a suitabl esky.

Then I would strain it through a big round wire strainer (four bucks from Sams warehouse) into a ten litre stockpot and collect about 8 litres, (edit: with 'fly' sparging from a kettle) then boil with the hop additions...

I once did a 2 kilo mash but it was pushing it to the extremes.

I don't worry about efficiency, the grain is just there for the malty flavour and goodness, body head and lacing... hence the warmish mash. I use the partial mash with a can of Coopers Lager and a kilo of dex, anything I get from the grain is just a bonus. Usually a small addition of bittering hops.. using POR atm and two smallish flavour aroma additions, BSaaz.

Like previous posters say, why are you using the grain? If it's for flavour and body then the efficiency isn't paramount. But if you are aiming for a super grainy malty strong beer then go AG, IMHO.

 

[RobboMC]

Why use the grain?

Primarily to get those grainy flavours and body - to improve the beer,
but having spent the cash on the grain I would like to maximise the benefits.

But also to gain eperience in mashing; so if I can do a great partial and get experience at mashing
then the step to AG is one of practicalities, not expertise. I am already hitting limits on heating, cooling,
sparging and so on. I am already dreaming of cooling coils and mash tuns.

The volume is a WAG ( wild ar*e guess) based on a 8.5 litre pot being nearly almost full,
the half kg of grain was, um, well pour half the bag. So the final efficiency calc could easily be out by 5% or more.

So don't get worried about just how good the efficiency was, I'm on the right track which is the main thing.

60-70 deg was roughly the temp of the wort AFTER I removed the grain, sat on the bench while I got ready, etc.
The mash was carried out from 65 up thru 72 deg mash out on a hot plate.

My wife has 2 of those square plastic boxes in the pantry for storage, and I have been eyeing them off, thinking 2 kg of grain per box, add the boiling water to the esky, 4kg of grain here I come. Glad to hear they work.

(un) fortunately I have now looked into a swirling pot of 1050 AG wort, luckily it was too hot to taste,
however I am starting to feel the draw towards the dark side.

 

[Bribie G]

Hey Robbo, if you are thinking of doing quite a few partials, I just ducked out to ALDI to do some shopping and I see that today they've got in a heap of little 7.8L round esky coolers with a tap for only $16. I reckon they would be the ducks nuts for doing just a kilo or even 1.25 mash and you could even do a batch sparge. Would prolly have got one myself if I was still doing the one-at-a-time partial mashes.

Yes the call of the dark side is irresistible isn't it

 

[buttersd70]

they've got in a heap of little 7.8L round esky coolers with a tap for only $16. I reckon they would be the ducks nuts for doing just a kilo or even 1.25 mash and you could even do a batch sparge. Would prolly have got one myself if I was still doing the one-at-a-time partial mashes.

I would have to strongly disagree, Bribie. A cooler of that size for that price is not the ducks nuts. Its the dogs bollocks.Pretty much the same, but able to be licked.

:lol: