Hello Grainfather Brewers
The recent conversations on this thread are about mash efficiency and the various effects of grain bill size, mill crush and sparging technique. As I'm new to AHB and brewing in general I've been scrolling through a lot of the forum threads recently. The information I have learned from this thread in particular has been invaluable. So thank you all. Given that many of us have come up against similar problems I thought I should summarise the best recommendations (dating back to to the threads beginnings!) and throw in my two cents worth after the grand total of two GF brews. I'll try to stick to GF specifics.
1.
Pay attention to water chemistry and mash pH
This may be obvious to the seasoned brewers but it wasn't something I paid much attention to initially, just threw in some Gypsum and didn't test pH. Many of you may be using RO or distilled water and are building your water profile from scratch (so you must know what your doing). I'm using boiled tap water and adding salts/distilled water. For my second brew I used the Bru'n water spreadsheet. Contacted my local water authority for average scheme water salt and pH values.
The first brew I didn't have a pH meter and I suspect my mash pH was nowhere near low enough and was a factor in poor mash efficiency (56%). The second time around I tested pH. I boiled the mash and sparge water the evening before to drive off chlorine. To my surprise the pH went from 7.1 pre-boil to 9.1 post boil. This is because boiling tap water drives C02 out of solution, lowering the bicarbonate concentration (removing temporary hardness). I therefore had to revise my salt and acid additions to achieve the desired mash pH (5.2 to 5.5). A pH meter is very helpful and got one for $49 at the LHBS . Also remember to add salts and acid to your sparge water to achieve a pH of 5.5.
2. Grain crush size does matter.
My first brew's mash efficiency was poor and consequently under shot OG by 20 points. In retrospect grain crush was a factor amongst others. I bought the grain pre-crushed and now that I know more about it realise it was far too coarse. It's said LHBS generally undermill (if you don't specify) as they don't want to be accused of creating a stuck sparge. For my second brew I purposely used a Grainkids Kit (The Belgian Witbier) as I wanted to see the crush size Amake used. The crush was a lot finer and I hit the OG bang on. I have a mill on order and will be playing around with crush size. Carniebrews share yesterday of graincrush recommendations on the GF Weekly Mash post is a good guide.
http://www.grainfath...839464746745922
3. Sparging
There has been lot's of talk regarding the best method to sparge. I haven't even come close to a stuck sparge (probably to do with crush size.) Start sparging straight after I pull up the mash tun and all over in 5 minutes, both times. The premature sparge, don't tell my wife. I was so concerned the first time that I might have been channeling sparge water through the grain bed that I removed the top mash plate half way through and gave it a good stir. It didn't seem to make any difference, probably worse. Others in this thread have reported sparge times as low as 5 minutes and some up to an hour. I think that if it goes through easily then don't worry too much, the GF people seem to think it should take up to 15 minutes. If you experiencing a slow/stuck sparge perhaps give it a stir. Advice in this thread suggests that if you wait too long for the mash tun to drain before sparging, the grain bed will compact too much and you are more likely to get a stuck/slow sparge. Use rice hulls if you have a big grain bill with lots of unhusked grain (e.g., rye or wheat). A 10 min mashout at 75C before sparging will also help the wort be more fluid and provide an easier sparge.
4.
The Boil
You should have hit the boil button as soon as you started sparging. Faster that way. Wait for the hot break before starting the timer for the boil. Even though Amake don't think it's required, use a Hop Spider or Sock, especially for large hop additions. So many brewers on this thread have found their pump has clagged with hops during the chill when they have big hop additions. My first brew was a hoppy APA and I dumped the hops straight in. It took me almost an hour to pump the wort into the fermenter because of the massive hop trub around the filter. Consequently my 5 minute hop addition hung around at 80+ degrees for ages so I way overshot on IBUs and didn't get the aroma I wanted. Second brew had a puny hop addition as it was a Belgian Wit but there was 5 minute Coriander and (powdered) Orange Peel addition. Chucked all this in the hop spider and had no problems with the pump. Piss easy to clean up as well.
5.
Using the Counterflow Chiller
What a cool piece of kit eh? Some debate in this thread about how long you should recirculate before dumping into the FV. The argument is that if you re-circulate until you get the wort down to 40 degrees or so you leave the cold break in the boiler rather than transferring it to the FV. But cold break is supposed to be good food for Yeasties and you should be able to leave the cold break in the primary anyway. Still haven't worked out what is best but I'm siding with the 'dump it straight into the FV camp' for now.
The chiller is most efficient if there is a high temperature gradient between the cooling water and the wort. On hot days when ground water is 28 degrees plus and you are anal about rapid chilling it is worth using a pre-chiller. A few months ago there was good advice given about using an immersion chiller coil in a bucket of ice water laced with pool salt to cool your tap water before it enters the counterflow. Tried this is on the weekend and it worked a treat. I'll take a photo next time. Other threads state that rapid chilling is over-rated and as you know there is whole tribe of no-chillers out there. It probably matters most if you are brewing a lager and don't want to hang around for ages whilst your wort chills in the fridge down to pitching temp.
Start counterflow chilling with the side-arm tap barely open and adjust the flow of wort and tap water to achieve cool wort. When the wort out hose feels cool lift it out of the boiler and direct it into the FV. If you are really worried about temp measurement you can stick a thermometer in a sample, or if you are really fancy there is something called a 'Thrumometer' which you can plumb in and measures the wort temp in the line. Around $50 at my LHBS but I don't think I'll bother.
I reckon that if you don't achieve a rapid chill don't sweat it. Some on this forum have said that Palmer's advice about the importance of rapid chilling is over-rated. Just let the wort cool in the FV until it reaches pitching temp and chuck it in the fermenting fridge to speed things up if you have one.
6. Cleaning Up
Clean up straight away. Clean your mash tun whilst the wort is boiling. Dismantle it entirely and dry throroughly. I have seen pictures of rusty bottom perforated plates where the nut traps water against it. Best to dismantle. The Grainfather cleaner solution seems to work fine especially if you recirculate at 50 degrees as per the recommendation. There may be just as suitable and cheaper cleaning solutions but for now I'm happy with the recommended stuff.
Well there you have it. A newbies limited experience. Please take me to task if i've said anything outrageous.
Cheers
Chris
