New AG garage brewer - sparge advice please

[davespencer999]

Hi everyone - This seems like the perfect place to get all sorts of wonderful help and advice. So here goes..

I have recently built an AG brewery in my garage (A typical home built affair, using lots of advice from the internet and books etc). I use Graham Wheelers bok which contains a great deal of advice, but also some great recipes. I regularly enioy Ringwood best, and a recipe for a similar beer is in Graham's book. So, I have now brewed it twice. The first time things went wrong (I expect mistakes for the first few brews so this is not a surprise or an issue) and I ended up with just 15L instead of 23L. On the plus side though, the beer should have been 3.8%abv, but turned out to be 5.4%.

Last weekend, I tried again using the same recipe to see if I could improve on it. However, I seem to have the same problem a second time - or is it a problem, or something I just am worrying unnecessarily about? (I use the word 'worrying' but it is never worrying to experiment with homebrew [emoji3])

Essentially, the recipe calls for just over 32L of liquor, with about 10L of it needed for the mash. So, I filled my mash tun (MT) with the 10L of hot liquor (HL), and after allowing a few mintes for the heat to be abosrbed into the MT, I started doughing-in the grist. I took a temperature reading after doughing-in, and the temperature had settled to a lovely 66'. I also took a pH reading after approx 5 mins of mashing, and it was a little low but ok (probably about 5.1 though difficult to get real accuracy with pH papers).
Anyway, the mash duration is 90m, after which time I start the sparge. My sparge arm is essentially 3 inter-connected copper pipes with a number of 1mm holes drilled into it (probably about 75 or so) below. I start to sparge and drain off the wort into my boiler, The first couple of pints of run-off are collected and put back into the MT.

Now, I have the sparge rate set as slow as possible to enable a nice gentle rinse from the sparge - much slower and the HL will not release itself as a nice rinse, but cling to the underside of the pipework, and form in small collective, more concentrated channels in half a dozen places along the sparge arm. The sparging takes about 15-20 minutes, by which time the wort is starting to become quite clear. The advice is that if the gravity of this run off falls close to 1.008 then to stop, otherwise some astringents will enter the wort.

This is my problem. By the time my wort has become almost clear, I am still about 10L short of wort in my boiler. The first brew I simply put down to bad technique, and boiled away, until I was left with 15L of fermentable beer.

Last weekend, on my second attempt, the same thing happened, so I simply topped up the boiler with cold water (I had run out of HL), and then started the boil.

My mash tun still had about 10L of HL in it which I discarded as its run-off was clear and fell to a gravity of close to 1.008. What, if anything, am I doing wrong? Is the sparge rate too quick? If so, I may beed to redesign my sparge arm (Picture attached). Any advice would be much appreciated.

Thanks
Dave

View attachment ImageUploadedByTapatalk1429249612.607482.jpg

 

[ManseMasher]

Are you starting to sparge straight away, or are you draining/lautering the mash tun first, then starting to sparge? 15 -20 minutes does seem a bit quick, 30 mins seems to be closer to the mark. How much dead space do you have in your tun and boiler? It only takes a couple of litres in each, plus grain absorption, to add up to a fair bit. Maybe try a batch sparge, and see if it changes anything?

Welcome to the forum by the way!

 

[clibit]

It doesn't seem like a problem to me, unless you are ending up under gravity. Which it would seem you are not. You simply need to add water to the boiler to make sure you start the boil with the correct amount. Which means you need to be able to measure the amount of wort in the boiler. If I'm understanding things correctly. It's odd that you are extracting all the sugars so quickly though. If you are, your system sounds super efficient.

 

[Godfather50]

It does take a little bit of time to get the volumes accurate. I can still be 5 liitres out on a brew which is 23 litres! Most are within about 2 litres. I sparge at a rate of about 1/2 litre a minute. The sparge lasts up to an hour. It normally uses 18 -20 litres. I don't use a sparge arm. I have a loop of silicon tube which sits on top of the grain bed. An inch or so of wort is maintained on the top of the grain bed. I don't take SG's at sparge. Don't taste any tannins. I get 80% - 85% efficiency.

So things I would look at are efficiency and if it is low may be look at the grain bed. Is all the sugar being washed out the grain. If not, may be look at sparge temperature. I keep my HL temp up about 90c. A temp probe in the grain bed shows the temp slowly rising during sparge from 70c to about 75c.

A simple test of residual sugar in the grain is to eat a pinch. You can taste residual sugar in grain in the corners of my mash tun where the rinsing is less than elsewhere.

I use Brewlog app to calculate volumes. Then write out my volumes which are something like:

Strike Water - 13 litres (78c)
Mashout - 6 litres (near boil)
Sparge - 19 litres (85c)

Then keep an eye on the total volume collected prebuilt, which for me is 35 litres.

All these volumes are adjusted according to amount of grain and boil time.

I've moved to 33 litre FV's, so if I produce 28 litres of wort (by mistake) it can still all fit!

Just remember that it all tastes great whatever the volume.

 

[davespencer999]

Thanks everyone. Lots of good advice to ponder over.

 

[Dads_Ale]

My initial thoughts are that your run off is much to short, you need to slow this down.
I must say that I do not bother measuring the gravity of my sparging but just keep going until I get the amount of wort I want'. This is usually about 35 litres.