controlling mash temperature.

[The_blue]

Hi guys, I'm about 60 brews in and still struggle to hold the mash temperature.

My last batch was a pain, I got the water to temperature and added the grain. The temperature sat must right but since I'm using an uninsulated boiler the temperature soon drops..?

I normally give it a 2 minute blst and stir to even out the added heat but this means I go from 67 to 64 to 68 to 65 etc etc... The last time I forgot to turn off the 2 min blast and ended up with a 82c mash with 30 mins remaining ..

I tend to mash with 20 litres of water and thern rince the grain with a kettle full of boiled water 2 or 3 times in a separate bucket. Total water of about 30 litres.

Would I be better adding all the water and skipping the rince? My thoughts being the larger volume in the boiler would be more stable to control.

I know I need to insulate the boiler. I have some silver bubble wrap at work waiting to be 'borrowed'.

[Fuggley Duckling]

I've got a cheap single duvet cover and pillow case and stuffed them with polyester insulation offcuts I got for cheap. The insulated duvet wraps around my pot (held where the ends meet with clothes pegs) and the pillow case sits on top. I only lose 2-3 deg f when doing a 60 min mash and not much more if I mash for longer. I do full volume mash.

[killer]

I also used to struggle with this quite a bit. In fairness you've mostly answered your own question. I was losing about 2°C every 30 min in an uninsulated polypropylene boiler. I upped my mash volume to the absolute maximum (about 24L in my case.) I also insulated with camping mats from decathlon and now only lose about 1°C per hour. I also tend to stir every 20 min or so.

I used to give a blast of heat every so often but this ended up over heating the wort in the bottom of the boiler as the bag stopped the heat being evenly distributed so I don't do this anymore. While this method works fine I have just added a pump to the tap and will recirculate in future (hopefully with the added benefit of filtering the mash).

[Manngold]

I wrap it in an old sleeping bag. Doesn't lose any temp over 90 minutes.

[pete69]

I used to BIAB and like Manngold used a sleeping bag - was perfect, never lost any heat.

[Cxp073]

When I used to have an in insulated tun I also used a sleeping bag.. Worked good.

[The_blue]

Thanks guys, my next batch will be a trial run of insulating and not kettle sparging

[orlando]

I tend to mash with 20 litres of water and thern rince the grain with a kettle full of boiled water 2 or 3 times in a separate bucket. Total water of about 30 litres.

Would I be better adding all the water and skipping the rince? My thoughts being the larger volume in the boiler would be more stable to control.

I know I need to insulate the boiler. I have some silver bubble wrap at work waiting to be 'borrowed'.

Look up batch sparging. You first of all drain the first runnings and then add your sparge water in 2 or 3 lots. I'm not familiar with BIAB but sparging will help with your mash efficiency, which is usually a little lower with this technique.

[Cxp073]

I think the best you can do with BIAB is to lift the bag, drain, lower the bag and then fill with 68c water (to the amount that you need), stir the grain and water and let sit for 10 minutes, lift bag, drain.

[alexlark]

^^^ That's what I do. Nice and simple. 70% efficiency no problem.