Table of Contents

## What is BIAB efficiency?

Extraction Efficiency The efficiency of any brewing process depends primarily on the water to grist ratio that you are using. Generally speaking, the efficiency of BIAB should be between 74-84% for beer OG’s between 1.040 – 1.075, lower OG having higher efficiency than high OG.

**How do you calculate grain absorption?**

1) Grain Absorption: Figure 1/2 quart per pound of grain. This comes out to ~1 pint (0.125 gallons) / pound of grain. Some reports are as high as 0.2 gallons per pound. During the mash process the grains soak up water.

**How do you calculate mash thickness?**

- Strike water volume = weight of grain X Desired mash thickness.
- Mash Water Volume = Strike Water Volume + Grain absorption.
- Total Mash Tun Volume = Volume of strike water + Volume of Grain.

### What do I need to BIAB?

The most noteworthy part of BIAB is the minimal amount of equipment needed. All you need is a Kettle, Large Bag, Heat Source and something to stir with. Your kettle needs to be big enough to handle the full volume of liquor (hot water) and grain.

**How do you calculate mash efficiency?**

To calculate your mash extraction in terms of ppg, you need to multiply the number of gallons of wort you collected by its gravity and divide that by the amount of malt that was used. This will give you the gravity (points per gallon) per pound of malt used.

**How are mash and sparge volumes calculated?**

First is to work backwards from the batch size to the preboil volume:

- Batch Volume + Boil Losses + (Boil Length * Boil Off Rate) = Preboil Volume.
- 23 L + 2 L + (1 x 3 L) = 28 L.
- Grain weight x Mash thickness + Mash Tun Dead Space = Mash Volume.
- 5 x 2.7 + 3.5 = 17 L of Mash Water.
- 1L @ 4°C = 1.002L @20°C.
- 1L @ 20°C = 1L @20°C.

#### What happens if mash is too thin?

A thinner mash results in better conversion efficiency, conversion efficiency being the % of total starches in the MLT being converted to sugars. In this case we increased the mash water from 1.25qt/lb to 2.0t/lb.

**How can we calculate the efficiency?**

To calculate the efficiency of a machine, proceed as follows:

- Determine the energy supplied to the machine or work done on the machine.
- Find out the energy supplied by the machine or work done by the machine.
- Divide the value from Step 2 by the value from Step 1 and multiply the result by 100.
- Congratulations!