This is done simply by multiplying the potential points for each grain by the weight of the grain. Recall that points are simply the fractional part of the potential — so an extract with a potential of 1. So for a simple stout with 8 lbs of pale malt 1. The potentials given for the grain are the maximum possible amount you could draw from the grains if you crushed them under laboratory conditions with no losses.
The brewhouse efficiency number includes all of the losses in the system into the fermenter including mashing, lautering, boiling, trub loss and transferring the finished wort to fermenter.
And that is the original gravity estimate if we convert it back to specific gravity — Now that we have our OG estimate, we can measure our OG when we brew the beer and see how well we did. Assuming you hit your target volume which also has a large effect on OG and your OG comes in low, you can reduce your brewhouse efficiency number next time which will make you use more grains to drive it up again.
Similarly if your OG comes in high you can raise your efficiency number making you use less grains to get back on target. We can also use the OG to get a rough estimate of the final gravity FG for our recipe. The simplest way to do this is to apply the average yeast attenuation to the OG to get the FG. You can also estimate the OG using mash efficiency which accounts only for losses in the mash instead of brewhouse efficiency. Multiplying the 57 by my 70 percent brewhouse efficiency gives us Which means, if I took a gravity reading at the end of the brew day and discovered I extracted more than 70 percent of the sugars.
I could dilute the batch with more water bringing down the OG. If I extracted less than 70 percent, I could boil longer or add an easily dissolvable fermentable like honey 36 PPG or corn sugar 46 PPG at the end of a boil to achieve the target Original Gravity. A brewer with the same recipe and an 85 percent efficiency could achieve the same 1.
Conversely, if they brewed with my 9 pounds and 4 ounces their 85 percent efficiency would result in a 1.
This substantial difference is why professional brewers talk in percentages - rather than pounds or kilograms - when describing a recipe, e. Jump to navigation. Sign-In Create Account. My Cart Account Support. Search form Search. Podcast Livestream Buying Events. What Is Original Gravity?
When discussing specific gravity, brewers tend to read 1. A hydrometer is one instrument used to measure specific gravity a refractometer and sacchorometer can also be used. Gravity readings are typically taken before pitching the yeast and after visible signs of fermentation have ceased. It is generally not recommended to take more samples than necessary because each time the fermenter is opened to draw out wort, you are introducing the risk for contamination.
To pull a sample, use a wine thief, siphon or turkey baster and take extra care with sanitation. Place the wort sample in a vessel big enough to allow the hydrometer to freely float without hitting the bottom or sides of the container. Some homebrewers buy a test tube, or you can sometimes use your wine thief or the container the hydrometer came in. Once the liquid is in the container, place the hydrometer in the sample and give it a gentle spin. The hydrometer will eventually settle and you can take your reading.
Sometimes the hydrometer will stick to the side of your vessel, so make sure it is floating freely before you take the reading. After you are finished, do not return your sample to the fermenter, as it could cause contamination.
Please wait The perfect libation for hot summer days. These steps are defined below: 1. Measure the SG of the finished beer, wine or mead a.
Calculate ABV The difference between these two specific gravities multiplied by is known as the spirit indication. Facebook Twitter Pinterest.
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