Low Gravity

[Gmull70]

I just did my second all grain ipa

9.5 2 row pale malt
1.0 crystal
0.5 melanoidin

1oz chinook
1oz cascade
1oz centennial

mashed at 152f for 75 min sparg at 170f took abot 40 min to yeild about 6.5 gal my og should have been about 1.062 i got 1.042 what should i do or what shouldnt i do

 

[Grizzlybrew]

First record your results and adjust your efficiency in your calculations so your next recipe will yield a beer closer to what you are looking for. Then, if you feel your current efficiency is low (which the above example seems very low), review your mash tun design and sparging method to see if you can increase your efficiency.

As far as the current brew - add 2 lbs of DME or 3 lbs LME. I would boil the extract at least 30 min (if not an hour), chill and pitch when the current beer is at high Krausen. Of course, the water you boil the extract in is going to further dilute your gravity - so, you may want to add an extra lbs of either extract if you are boiling in 1 gallon of water.

 

[enkamania]

Here is a link I found on this site for gravity adjustment. http://www.ahomebrewlog.com/gravity_adjustment/

 

[Gmull70]

First record your results and adjust your efficiency in your calculations so your next recipe will yield a beer closer to what you are looking for. Then, if you feel your current efficiency is low (which the above example seems very low), review your mash tun design and sparging method to see if you can increase your efficiency.

As far as the current brew - add 2 lbs of DME or 3 lbs LME. I would boil the extract at least 30 min (if not an hour), chill and pitch when the current beer is at high Krausen. Of course, the water you boil the extract in is going to further dilute your gravity - so, you may want to add an extra lbs of either extract if you are boiling in 1 gallon of water.

What do you mean by adjust efficiency. how is that done still a new brewer here

 

[Grizzlybrew]

What do you mean by adjust efficiency. how is that done still a new brewer here

Well, adjusting efficiency is not cut and dry. What I meant, is for example, look at your false bottom or manifold design. Is it designed in a way that there is an equal draw of liquid from all parts of the mash tun (where is the pick-up tube? is there a symetrical design?)? Could you mash with a tighter grain/water ratio and reserve more of the sparge water to further rinse the grains? Could the perforations/slots of the false bottom.manifold be sized differently?...

If you understand how the design of your mash tun and how your mashing/sparging techniques can affect your efficiency, you can make small adjustments to those processes/equipment and see a change in your efficiency.

 

[Bernie Brewer]

Did you take your reading pre-boil or post- boil? and at what temp? When I finish sparging my temp is usually around 130F. Adjusting for temp, that gives you a pre-boil gravity of 1.056. after boiling for an hour and ending with a volume of 5.5 gallons, you should have ended up with a gravity of 1.066 at 60F. how and when did you take your readings?

 

[emdiar]

What do you mean by adjust efficiency. how is that done still a new brewer here

Efficiency refers to how much sugar you extract in your conversion process as a percentage of the maximum amount that could be extracted under certain idealized lab conditions (there are two or three standardized tests that are used to determine the potential for different malts).

I'm pretty new at this too, but the gist of it is that after you've brewed enough batches you can figure out what your efficiency is, which will help figure out the water/grain ratio that will yield the gravities you want from your recipes. Recipes have to assume some baseline efficiency, but it may be necessary to use more grain if your process is less efficient.

Here's a Wiki article about it.

 

[Grizzlybrew]

What do you mean by adjust efficiency. how is that done still a new brewer here

Oops. I just realized I didn't really understand your question the first time. Or, at least, I over analyzed it. The post quoted below is what I should have written.

Efficiency refers to how much sugar you extract in your conversion process as a percentage of the maximum amount that could be extracted under certain idealized lab conditions (there are two or three standardized tests that are used to determine the potential for different malts).

I'm pretty new at this too, but the gist of it is that after you've brewed enough batches you can figure out what your efficiency is, which will help figure out the water/grain ratio that will yield the gravities you want from your recipes. Recipes have to assume some baseline efficiency, but it may be necessary to use more grain if your process is less efficient.

Here's a Wiki article about it.

Your efficiency can change from batch to batch depending on grist makeup, temps, mash/sparge ratios, etc. But, it should remain somewhat constant.

When I initially said "adjust your efficiency", I was referring to adjusting your expectations of efficiency when calculating your recipes. Brewing software has this built into the interface. If you've read Designing Great Beers, then you would take your efficiency into the equations you work out. In both scenarios, I was assuming you design the recipe yourself; in which case, you need to know your efficiency to get the beer you plan to brew.

 

[midfielder5]

sparge w hotter water (not 170* water; grain bed should be 170-175*) and after adding sparge water, stir the grain to dissolve the remaining sugars, then vorlauf.

You might need to add 1-2 pounds of base malt if your system has poor efficiency. Most recipies assume 70-75% eff.