Efficiency is a huge variable and can even change from recipe to recipe.
It has a lot to do with your process and your ingredients but a few things you can do to help with efficiency include;
- Crush your grain slightly finer
- Make sure your mash pH is between 5.2-5.6
- Ensure you have enough base malt in your recipe to fully convert any specialty grain
- Make sure you mash in thoroughly, all grain should be soaked and there should be no dry clumps. Every 20 minutes, turn off the recirculation and stir the grainbed
- Make sure you sparge slowly, allow the water to drain fully when you first pull the grain basket up and then start your sparge, never allowing the water to build up too much on top of the perforated plate.
- Your sparge water should be at 75°C (167°F)
- Include a mash out – the effect on efficiency of a mash out is low but can help you get a few extra points.
It's a combination of these things that will help improve your efficiency so just trial different things until you find your maximum efficiency.
If it is quite low, see further information here - Your efficiency could be low for a number of reasons.
Gravity is measured in the amount of fermentable sugar present in the wort, these are made available through choosing your grain bill, milling and mashing.
- Make sure that your crush is correct - a medium crush is recommended, you also need to make sure that the grains you are using have the correct diastatic capacity for what you want to make.
- Make sure you are recirculating the whole time during the mash and that you are using the correct mash temp. The sparging process should last at least 20 minutes. Anything less will result in a lower OG since the grains will not be fully rinsed, and you will risk leaving fermentable sugars in the spent grain. Also, make sure the sparge water is 75°C (167°F). Sparging at this temperature will ensure that the residual sugars in the mash are collected efficiently since the sugar will dissolve into the sparge water more easily.
- We recommend pushing the top plate to gently rest on the grain bed, do not press too hard as this will compact your grain bed and impair proper flow. Use a jug to pour the sparge water over the top plate, and make sure to at all times have a 2 cm water level above the plate - doing this will maintain grain bed integrity whilst adding enough pressure to rinse out to sugars.
Why is the Mash Efficiency off?
- The mash efficiency might be set too high for this recipe, could be crush, raw materials or user error.
- The fastest way to get accurate brewing is to do the recipe again, but adjust the mash efficiency from 80% down to 75%, adjust the grain bill so that you get an OG back to 1.047 and re-brew the recipe.
- When you brew, after you have finished the sparge and removed the grain basket, stir the wort and take a gravity reading. Use the mash efficiency calculator on the Grainfather app to get what your mash efficiency is.
- If the mash efficiency calculated is different to the 75% used then next time use this new mash efficiency for the calculations.
- If the mash efficiency is the same (75%) and then you still get low or high on your OG then you need to adjust your boil-off rate (difference in volume between pre-boil and post-boil) to account for the change in gravity as a result of the loss of water.