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Jivinwilly70

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Consistently my pre-boil gravity numbers after mash out and sparging have been around 10 points lower than the recipe calls for.  Lots of factors involved, but don't know what the problem may be. Any ideas greatly appreciated.  :mad:
 
Start by looking at your brewed beers.  Are you hitting the volume targets consistently?  You don't need to be nuts on, but you do need to be close for all the important volumes:  Est Pre-boil volume, Batch size, loss to trub and chiller.  If you are way off from the targets in these fields, then you need to straighten out your volumes in BeerSmith to match your measured values.  From water into the mash and pre-boil volume, you should be able to get loss in your mash tun and absorption value.  Pre-boil measurement to post boil measurement will give you a rough idea on boil off rate.  Update your equipment profile with these calculated values. then look at your efficiencies.

On the 'session' tab, there will be a calculation for 'Meas Efficiency' and right above that is the BH Efficiency that the recipe was designed for.  If your measured volumes are in line or close to the targets, then you are not extracting the amount of sugars that you are designing the recipe around from the grains.  Adjust your BH efficiency in your equipment profile to match what you have been achieving. 
 
Thanks Oginme.  Checking back on past brewing, volume numbers are for the most part on target. So that leaves me to think that not enough sugars are coming out of the mash tun.  Is the sparge process not achieving what it should? or, is my grain bed incorrect for that particular recipe?  By the way, most of my brews turn out ok, by the numbers, but this particular recipe for my Wit beer has always been short on OG.  Should have mentioned that. Thanks.
 
Here is an easy to follow tutorial for setting up an equipment profile for your particular system. This channel also has tutorials on setting up custom mash profiles.

https://www.youtube.com/watch?v=QmW7pwQP5mQ
 
Jivinwilly70 said:
Thanks Oginme.  Checking back on past brewing, volume numbers are for the most part on target. So that leaves me to think that not enough sugars are coming out of the mash tun.  Is the sparge process not achieving what it should? or, is my grain bed incorrect for that particular recipe?  By the way, most of my brews turn out ok, by the numbers, but this particular recipe for my Wit beer has always been short on OG.  Should have mentioned that. Thanks.

If you are hitting your pre-boil volume and gravity coming from the mash, then it is not your mash efficiency out of line, but your losses during the boil.  You also cannot be hitting your pre-boil volume and gravity figures without getting your post boil numbers correct if you have your process defined correctly in your equipment profile.  This would indicate either your boil off is incorrect, your volume measurements are not correct and/or your gravity readings are incorrect.

Start with what Kevin58 has recommended for getting your equipment profile set up properly.  Once you have your process defined well, see how your past numbers fit that model.
 
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