We then tested the impact that manual extraction has on overall filtration and body. By manual extraction, we mean that last step of the brewing process when it is allowed to drain on its own or squeezed to extract every last drop. To test this, we did a series of test batches where one was not even allowed to drain, one was drained but not squeezed and one drained and squeezed .
TDS - One of the ways to determine extraction/filtration is to measure the Total Dissolved Solids. Typical ranges of TDS for cold brew concentrates are between 3.00% to 3.50% (also referred to as a TDS of 300 to 350).
- Not Drained - 316
- Drained Only - 317
- Squeezed - 310
Sediment - One of the defining characteristics of cold brew is the body, and sediment plays a big role in that. Every batch we’ve ever made has had sediment in it, but to varying degrees. While not a perfect test, we tipped the glass jars to see how much sediment had collected after 24 hours.
- Not Drained - low sediment
- Drained Only - low sediment
- Squeezed - high sediment
Conclusion - From our preliminary tests, manual extraction had a minimal effect on the TDS but did significantly affect the level of filtration. We found that squeezing had a large and direct impact to the level of sediment and mouthfeel of the final product.
Keep in mind that we are brewing a concentrate. Another way to adjust the TDS, body and mouthfeel of your cold brew is to adjust the dilution ratios to perfect your ready-to-drink offerings.
Thanks for following along! Monday, we will tackle Grind Size.