I keep getting lower than expected original gravity.

[dannymars]

It would also depend on where you are measuring the temp that controls the STC... You lose some heat through the hoses as the wort is being pumped, the amount of loss also depends on how fast you are pumping it through, how long the hoses are, whether they are insulated or not.

 

[CyberAle]

It would also depend on where you are measuring the temp that controls the STC... You lose some heat through the hoses as the wort is being pumped, the amount of loss also depends on how fast you are pumping it through, how long the hoses are, whether they are insulated or not.

My temperature probe is located right where the pump comes out at the top right above the grain bed

 

[CyberAle]

So I did another brew yesterday, my grain bill was:
5.25 kg of Maris Otter Ale Malt
0.25 kg Vienna Malt

I made this grist with the efficiency in Beersmith at 60%. I mashed at 67C for 60 minutes.

I got a brix reading of 7.5 Plato at 30C after cooling the boiled wort, so we can rule out Joe White malt as the cause. This is ridiculous. The wort though looked very very dark, it should not be that dark considering the grain quantity adjusted at 60%. I beginning to think that maybe my refractometer is stuffed and my mash tun may actually have no efficiency problems at all.

 

[MHB]

As you are in Adelaide, it is also worth considering that your water may be quite alkaline, if the pH is too high, you will get low OG's, Dark beer and really rough bitterness.
Worth owning an hydrometer you can trust and making sure your sensors are telling the truth.
Mark

 

[Lethaldog]

Also consider the speed of your flow out of the tun and whilst sparging, how long does your transfer from mash tun to kettle take? In my first few all grain brews I had a similar problem then slowed up the flow out of the tun and get 80%+ consistently and a lot of that was with JW so I can't see that being your problem, I'm sure it could be a number of things but there's just one more for you to check[emoji106]

 

[Mantis]

Getting low effs too and using JW malts for the base. I did experiment with very slow draining of first runnings which improved things a bit but not worth the wait. Will try different malts in future as well to see if that helps with my setup. Beer still comes out great so not too concerned

 

[CyberAle]

Awesome, I think I may go to west end brewery and grab some of their water, as they supply their treated water for free. I have my water pump going at full ball, I will definitely slow down heaps and see if that helps thanks a lot guys

 

[Mantis]

Water chemistry helps too, ask them about stuff to put in the mash water to acidify it. This helped me too but I have let it slip as I am happy with my results just using rain water. Try different stuff as we all do but if you get a good result that you like drinking dont get too concerned. Enjoy brewing

 

[manticle]

Getting low effs too and using JW malts for the base. I did experiment with very slow draining of first runnings which improved things a bit but not worth the wait. Will try different malts in future as well to see if that helps with my setup. Beer still comes out great so not too concerned

OT but welcome back.

 

[TheWiggman]

Looking through the thread nobody has talked about volumes (except indica). A simple way to reduce your gravity is to add water to the brew, or dilute it in one part of the process. You're talking about OG and efficiency and forgetting about all the other important stuff.

Eg:

1. Mash in 5kg grain to 15l water
2. Sparge until you get 30l in the boiler

If you have 23l in the fermenter at 1.050, you have the same efficiency if you have 29l of 1.040. However if you lose any of that 29l elsewhere in the process and end up with 23l in the fermenter your problem is wastage, not extraction efficiency / getting sugar out of the grain.

How much has been left in the mash tun? If you have 10l of dead space - which seems extreme - you're throwing a fair portion of your sugars away with your grain when you tip out your mash tun on the compost. This is what manticle was hinting at, you need to tune BeerSmith to your system to get the results you want. Prior to that, optimise your system so you're minimising waste and in general supporting good brewing practice so everyone wins.

 

[manticle]

Once you get a brand spanking new hydro and check your refrac, go through every step and measure gravity and volume as you go. You need to find out where any weak/suspect points are before you know how or what to fix.

Make sure your thermometer is accurate too.

 

[Lyrebird_Cycles]

Also consider the speed of your flow out of the tun and whilst sparging, how long does your transfer from mash tun to kettle take?

I did experiment with very slow draining of first runnings which improved things a bit but not worth the wait.

It's not the flow rate as such that is the problem, it's the differential pressure*, especially the DP of the forerunnings which is the period that sets the bed.


Fore run hook

I've been thinking about controlling this for a while and recently built this device to help. It's held in place by a pulley system which controls the height difference between the top of the hooked portion and the fluid level which in turn defines the differential pressure. The clamp controls the flow rate at the set DP.

I might have to add a short length of clear tube to the vent but if I can keep the DP below 0.3 kPa I won't need to. I use a different method on the main runnings.




*Of course the two are related: for a given average Darcy permeability of the bed one will track the other but that's actually the point: you want low DP and medium permeability which will define the flow rate.

 

[CyberAle]

How much has been left in the mash tun? If you have 10l of dead space - which seems extreme - you're throwing a fair portion of your sugars away with your grain when you tip out your mash tun on the compost.

Sorry, no I don't have 10L deadspace, 10L is just the gap between the false bottom and the base of the Mash Tun. I have very little deadspace, 1-2L max (if I understand correctly deadspace is the wort you cannot mash out because it is not higher then the mash out tap).

 

[mckenry]

Terminology is a bit wrong there. Mash out is raising temperature to end conversation. Mash out tap? I think you might mean outlet tap? Dead space is the volume of wort you can't get out post mashing, to the boiler. If it's a single vessel it's therefore 0 but you then have kettle dead space anyway.

 

[CyberAle]

Yes thanks, I was struggling to think of the proper term for the outlet tap lol.

 

[Rumper]

Not sure on your water to grain ratio but i usually run about 3.1 to 3.2 litres per kilo

 

[Jack of all biers]

As you are in Adelaide, it is also worth considering that your water may be quite alkaline, if the pH is too high, you will get low OG's, Dark beer and really rough bitterness.
Worth owning an hydrometer you can trust and making sure your sensors are telling the truth.
Mark

A bit of a myth about Adelaide water being quite alkaline. The average pH values are stated to be between 7.2 and 7.4 for just about all of the Metro area water supplies. The majority of the Adelaide water supply comes from Central which has a recorded 2016 average of 7.4. I measure it out of my tap every brew day (pH meter two point calibrated accurate to 0.01) and consistently get around the 6.8 mark.

 

[CyberAle]

Hi guys,

I hit my target gravity last brew with a setting at 70%. I used West End's Brewing water from their Well, had my pump set to about half the flow I usually do, however, the embarrassing thing is, I decided to actually measure with electric scales the measuring container I had been using to measure out my quantities and it turned out that what I had been measuring out to 1 kg on the container was only 750g ! Thus I was only putting 75% of the amount I was planning to. But this is only valid for the last couple brews, before that when I was using 4 kg bags of milled grain from my local store I was still getting a much lower target gravity, so I am suspecting that these 3 changes I made at once all seemed to have fixed my problems. Anyway thanks heaps for all your help! I learned a valuable lesson about being thorough with all my brewing practices.

 

[klangers]

Yeah cannot agree more with sorting out your metrology first. I had pretty crap efficiency, until I actually sat down and sorted out my measurements. Turned out it was how I measure my sparge water and I was consistently under-sparging.

 

[dblunn]

I have a question regarding sparge technique which is somewhat related to this thread and I would like to hear the views of some of you experienced folk. I have a 3 vessel system with a separate HEX.
Which of the two following scenarios would be better a) sparge until the predetermined volume of sparge liquor has been added to the mash tun, stop adding sparge liquor and then continue draining the mash tun until the required kettle volume is reached (which should coincide with the mash tun running empty) or, b) keep adding sparge liquor to the mash tun until the required kettle volume is reached? Are the two methods equivelent or is one method totally wrong?
Regards, Dave