Mashtun drainage/filter vs efficiency

[svenito]

I have a square Igloo cooler with a round false bottom (kinda like this one https://www.brewuk.co.uk/delux-insulated-mash-tun.html) and my efficiency isn't great. I was wondering if I were to make a copper "grid" like this https://cdn2.brewersfriend.com/copper1.jpg can I expect a better extraction from that alone?

I've adjusted a few things already like temp, sparge steps, etc, but would like to know if it's worth making one of these or not. Or can I expect a similar boost from the braided hose option, if I do a single loop?

 

[ACBEV]

I have a cooler type mash tun with a braided hose filter and get good conversion, around 80%+.

For me I need to get my ducks in a row to achieve this... Mash PH, temperature and time are the three most important things I need to get right.

I mostly do an old fashioned double mash with no sparging, this give plenty of time (2 hours) for the grain to do its thing. I always start my mash schedule at 2.5L of water to 1kg of grain i.e. for 5kg of grain = 12.5L of water.

Example: my house bitter mash schedule...

4kg Grain.
1st mash...
62c for 20 minutes - 10L strike water @ 69.4c (mash in)
67c for 40 minutes - 1.8L boiling water added (mash in)
72c for 30 minutes - 6.7L top-up water @ 73c (mash in)
Slowly drain mash tun to bucket (first runnings)
2nd mash...
75c for 30 minutes - 15L water @ 76c (mash in)
Slowly drain mash tun to bucket (second runnings)
This gives me around 27.5L for boiling and around 22L for my FV.

For other beers I may have a simpler mash schedule i.e. 60 mins @ 67c, 30 mins @ 72c and 30 mins @ 75c... Whatever suits the beer I'm brewing.

 

[Ciaran12s]

I like the braid personally. Prior to that I used a bazooka type and it kept sticking. The braid doesn't stick.

Thoughts for improvement when I get the time and inclination;

Replace the 50cm braid with 1m.

Weight this at intervals with some tube as it tends to float.

Get the sewing machine out and make a sleeve to fit round the braid from some old pillowcase or something. The idea here being to add an extra filter to cut down on particulates coming through.

Although I have improvements in my mind I'm still very happy with it.

 

[svenito]

Thanks for the replies. I've started doing a double sparge by splitting the sparge water into two and letting each sit for 15minutes before lautering. With my current setup I managed to get 73% which was a big increase from around 60% before.

Seeing as the braided hose is going to run much cheaper, I reckon I will go with that. I can fit around 1m in there with a Tee connector to the ball valve. I think I might slide some copper tube bits into the braid then to weight it down, thanks @Ciaran12s

I'm not too worried about little particulates.

 

[Clint]

My efficiency jumped considerably when I changed to 2 spares,also looking through my notes my highest seems to be when I had to leave the mash for 2 hours. ACBEV, interesting method...I must try!
Edit. ..why does increasing the mash temp gradually affect the efficiency against say,my 2 additions that keep it at around 66°c?
Where can the braided hose be found?

 

[BeerCat]

Get a refractometer and check it as the mash progresses. I always mash for more than an hour. I don't use one of these but when i mashout i always get 4 extra gravity points.

 

[ACBEV]

Where can the braided hose be found?

Google search for "stainless steel braided sleeve", also can be found on ebay. You can also find braided flexible pipes at B & Q, but you will need to dismantle and remove rubber inner hose. bunge one end and clamp the other.

 

[svenito]

I saw some on ebay for 8quid a meter. At screwfix you can get a braided hose for 3quid a meter, but as @ACBEV said, you have to dismantle it. I'm going to go for the screwfix one, as I can also pickup the rest of the bits I need there. I'll post about the build on my blog when it's done. :)

 

[ACBEV]

when i mashout i always get 4 extra gravity points.

This is a very good point... Getting the temp. up at the end helps quite a bit. I don't quite mashout, but raise the temp for my second mash to 75-76c for 30 mins. Also I think stirring at each stage helps too.

 

[Wouter]

I sparge with water of 95C, works like a charm for mashing out ^^,.

 

[Clint]

thanks ...out of interest here's brew dog slot machine mash schedule. ..if you can see it!

 

[Spoon]

As long as it's consistent it's not the end of the world, a 10% jump in efficiency might cost/save you £1 in grain, its not like a commercial brewery where 1% is costing £100s Or £1000s in grain and power.

My mash tun is round with a slightly undersized round false bottom, the logic behind that is that the pressure drop down the side of a packed bed is always less so you need to draw liquid away from the walls rather than down them otherwise the sparge water is bypassing the grain.

I only do a single 60min mash and 15min mash out and I get mid 70's brewhouse efficiency (so that includes losses in the kettle etc).

62c for 20 minutes - 10L strike water @ 69.4c (mash in)
67c for 40 minutes - 1.8L boiling water added (mash in)
72c for 30 minutes - 6.7L top-up water @ 73c (mash in)
Slowly drain mash tun to bucket (first runnings)
2nd mash...
75c for 30 minutes - 15L water @ 76c (mash in)

I'm not sure that's doing much from a chemistry point of view? The first mash at 62 will convert the starches to simple sugars, then the second step at 67 can't produce longer unfermentable sugars. Then mashing out at 72 denatures the enzymes which will stop any further conversion. Conversion is usually complete in the first 20min, hour long mashes are more about tradition than science.

Breweries have sometimes reused the mash, but add more grain to give it fresh enzymes. The other variation is to take second runnings so a mash is done with full volume of water, drained then re-filled with water, this gives you two beers, one strong and one weaker. IIRC Fullers still do this and blend the first and second runnings to produce a variety of beers (I.e. Pride, ESB etc are all the same mash).

 

[svenito]

As long as it's consistent it's not the end of the world, a 10% jump in efficiency might cost/save you £1 in grain, its not like a commercial brewery where 1% is costing £100s Or £1000s in grain and power.

True, you can account for efficiency in your recipes. In my case though it's about curiosity to see if a different draininage solution will make a difference. My current setup also doesn't allow me to stir properly during mash in. If I stir it too far down, it tends to lift the false bottom which causes some of the grain to go under it. This has caused some stuck sparges in the past, to the point that I have even reached in and removed the filter entirely and relied on the grain bed to its job. The braided steel should alleviate this problem I reckon.

 

[Fil]

when calculated my 3v bhe has been high 70's low 80's using a simple batch sparge, granted by habit i always throw in an extra handful of un-weighed grain into the tun as a rule of thumb counter for the mythical loss of efficiency due to the batch sparge..

When it comes to sparging i simply heat upto my sparge temp 78c-82c usually depending on time of year, and top up the tun to the brim before giving it a good mix in..

20-30 minutes later i drain the tun into the kettle and measure the volume recovered. I then subtract that from my preboil voulume target to determine the volume of water to add for batch sparge #2 which i perform while the 1st drawings are heated.

for tun drainage ive used both SS mesh tubes and false bottoms, i prefer false bottoms.. if you do use mesh tubes, be mindful to clean well, i found soaking alone insufficient, post clean flex violently, if no 'dust' is generated your done but if you generate a cloud of flour clean and flex test again.. that flour if left unchecked can result in a stuck mash..

and if concerned about the grain mass crushing your mesh tube, insert short lengths of copper tube butting up against each other inside the mesh, you could drill a few holes but off square cut ends work best

to counter a wobbly fb,
1) underlet, filling the tun via the drain with the strike liquor seems to saturate the grain more efficently than when added from above requiering less mashing in.

2) use a grain bag to contain the grain mass if you upset the fb no grain will fall thru

 

[Wouter]

1) underlet, filling the tun via the drain with the strike liquor seems to saturate the grain more efficently than when added from above requiering less mashing in.

This also makes your wort less clear because you are disrupting the filter (the husks! not! the big filter, but the husks!).
Wether or not that matters is debatable.

 

[svenito]

I put the filter together this weekend, have yet to give a proper try though. For anyone interested, here's what I did https://wurstbrewery.co.uk/2018/04/mashtun-upgrade/