Brazhnaya gravitsapa appeared a couple of years ago after the positive effect of marble on the fermentation and acidity of the must was proven. But it is inconvenient to get marble from the mash before distillation, so the distillers have developed special submersible devices.
Principle of operation. Brazhnaya gravitsapa is a container, in the bottom of which there are holes for the entry of mash, and the upper part has a conical shape for the normal exit of the water-gas mixture under pressure. Inside the container is filled with pieces of marble gravel. Upon contact with the mash, carbon dioxide is released on the surface of the gravel.
Thanks to active gas formation, a pump is obtained from the gravitsapa, which works without pumps and external energy sources, replacing a similar aquarium pump, which is used by some distillers for accelerated fermentation.
Benefits of a beer gravitap:
- increases the speed of fermentation – on average, the mash will win back in 2-3 days on baker’s or alcohol yeast;
- reduces the acidity of the mash;
- indicates the end of fermentation more accurately than the absence of gas from the water seal, and sometimes the saccharometer.
Regarding the last advantage. For example, due to a measurement error, the saccharometer may show 0% sugar, but if the mash over the gravitsa continues to boil or there is a slight gushing, it means that there is still some sugar left and needs to be fermented.
Disadvantages of a gravipap:
- suitable only for liquid mash, which do not have large particles of pulp or grain that can get stuck in marble, mainly the device is used for sugar mash;
- the hydromodule 1:5 is desirable.
How to make a gravitsapa for mash
You need:
- marble gravel (crushed stone) – 1 kg (approximately);
- plastic bottle with a volume of 1,5 liters with a conical top – 1 piece;
- nylon cable ties – 9 pieces;
- the length of the lace – for immersing the gravitsapa in braga;
- drill – for making holes.
Suitable for any PET mineral water bottle with a cone-shaped top. The optimal weight of pieces of marble gravel is 40-80 grams, approximately like a quail egg. If the pieces are too small, then this will make it difficult for the mash to move inside the gravity cap and the useful effect of the device will be lower. Too large pieces of marble reduce the useful area of contact between marble and mash.
Manufacturing technology:
1. Remove the label from the bottle and remove the remaining glue – the easiest way is to wipe the glue with vegetable oil, then rinse with dish detergent.
2. Divide the bottle into 2 parts. Make an incision about a third of the length, counting from the neck.
3. At the bottom of the bottle, at the bottom of each protrusion, make a hole with a drill with a diameter of 12-14 mm. Then along the hole 8-10 mm in the recesses closer to the center of the bottom.
4. At the top of the bottle, drill 3 pairs of holes at about 120 degrees each pair. In total, 6 pieces with a diameter of 8-10 mm should be obtained.
5. Insert the top of the bottle into the bottom so that both halves are securely held. On the bottom, mark the end of the overlap.
6. At the bottom of the bottle below the overlap line, also make 3 pairs of holes at 120 degrees.
7. Insert 1 cable tie into each pair of side holes, tighten, then cut off excess cable ties. You will get loops, thanks to which it will then be possible to connect both parts of the beer gravitsapa.
8. Fill the bottom of the bottle with marble.
9. Put the top of the bottle on the bottom. Fasten both parts securely with loop cable ties (made in step 7). Trim the ends of the ties.
10. Tie a string to the neck of the bottle for easy immersion and extraction of the gravity cap.
More on video.
How to use a beer gravitap
Instructions:
1. Put the mash at the rate of 5 liters of water per 1 kg of sugar. Bring in yeast.
2. After the start of active fermentation (a lot of foam is released), install a gravicap. Close the mash with a water seal (preferably).
Attention! When using a beer gravitsapa, over time, the mass of marble decreases due to contact with the acidic environment of the beer. Also, during fermentation, grains of sand break off, which also reduce weight. This phenomenon does not affect the quality of the mash and the safety of moonshine.